{"gene":"UNC13D","run_date":"2026-06-10T10:51:56","timeline":{"discoveries":[{"year":2003,"finding":"Munc13-4 (hMunc13-4) is essential for the priming step of cytolytic granule secretion preceding vesicle membrane fusion in cytotoxic T lymphocytes. Mutations in UNC13D cause FHL3. Deficiency results in defective cytolytic granule exocytosis despite normal polarization and docking of granules to the plasma membrane. Expressed tagged hMunc13-4 localizes with cytotoxic granules at the immunological synapse.","method":"Patient mutation analysis, subcellular localization of tagged protein (fluorescence microscopy), functional exocytosis assay in patient cells","journal":"Cell","confidence":"High","confidence_rationale":"Tier 2 / Strong — first identification paper with mutation analysis, localization experiments, and functional exocytosis assays; independently replicated across multiple subsequent studies","pmids":["14622600"],"is_preprint":false},{"year":2003,"finding":"Munc13-4 is a GTP-Rab27A- and Rab27B-binding protein in platelets. Recombinant Munc13-4 directly binds GTP-Rab27A and Rab27B in vitro but not other GTPases, and enhances dense core granule secretion in a permeabilized platelet assay. Inhibition of secretion by unprenylated Rab27A was rescued by addition of Munc13-4, demonstrating that Munc13-4 mediates the effector function of GTP-Rab27.","method":"Affinity purification, in vitro binding assay (recombinant proteins), permeabilized platelet secretion assay with rescue experiment","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1 / Strong — in vitro reconstitution with recombinant proteins plus functional rescue assay; replicated in multiple subsequent studies","pmids":["14699162"],"is_preprint":false},{"year":2006,"finding":"Missense mutation Leu403Pro in hMunc13-4 prevents formation of a stable hMunc13-4/Rab27a complex in vitro, demonstrating that specific residues in Munc13-4 are required for Rab27a interaction.","method":"Mammalian two-hybrid system (functional protein interaction assay in vitro)","journal":"Human mutation","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — mammalian two-hybrid, single lab, functionally informative missense mutant","pmids":["16278825"],"is_preprint":false},{"year":2008,"finding":"In human neutrophils, Munc13-4 is mainly cytosolic at rest and is rapidly recruited to membranes following fMLF stimulation in a Ca2+-dependent manner. A pool of Munc13-4 associated with secondary and tertiary granules is relocalized to the plasma membrane after fMLF stimulation. C2 domains of Munc13-4 bind phospholipid vesicles in a Ca2+-independent manner. Knockdown of Munc13-4 decreases tertiary granule exocytosis; overexpression enhances MMP-9 secretion.","method":"Cell fractionation, immunofluorescence, siRNA knockdown, phospholipid binding assay, secretion ELISA","journal":"Journal of immunology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple orthogonal methods (fractionation, localization, KD, OE, binding assay) in single lab","pmids":["18453599"],"is_preprint":false},{"year":2008,"finding":"Doc2alpha co-localizes with Munc13-4 on secretory lysosomes in mast cells and interacts with Munc13-4 through two regions: the N-terminus (containing the Munc13-1-interacting domain) and the C-terminus (C2B domain). This Doc2alpha–Munc13-4 complex regulates Ca2+-dependent secretory lysosome exocytosis; mutations in either binding region or Doc2alpha knockdown impair exocytosis, rescued by Munc13-4 coexpression.","method":"Co-immunoprecipitation, co-localization (confocal microscopy), dominant-negative mutant expression, siRNA knockdown, rescue experiment, knockout mouse BMMC assay","journal":"Journal of immunology","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal co-IP, co-localization, KO mouse, mutant rescue; multiple orthogonal methods","pmids":["18354201"],"is_preprint":false},{"year":2008,"finding":"Munc13-4 regulates exocytosis of multiple neutrophil granule subsets (gelatinase/tertiary granules). Munc13-4 localizes at secretory organelles in neutrophils. Using Munc13-4-deficient (Jinx) mouse neutrophils, Munc13-4 was shown to be required for exocytosis of various secretory organelles, though CD11b mobilization was not affected.","method":"siRNA, total internal reflection fluorescence microscopy, Unc13d(Jinx) knockout mouse neutrophils, granule secretion assays","journal":"Traffic","confidence":"High","confidence_rationale":"Tier 2 / Strong — KO mouse model plus TIRF microscopy and multiple secretion assays; replicated across labs","pmids":["18939952"],"is_preprint":false},{"year":2009,"finding":"Munc13-4 and Rab27a are recruited to lytic granules in a stimulus-dependent manner in NK cells, but different receptor signals preferentially recruit Rab27a vs. Munc13-4: NKG2D and LFA-1 engagement induced Rab27a but not Munc13-4 colocalization with perforin, while CD16 (ADCC receptor) engagement induced Munc13-4 but not Rab27a colocalization. Colocalization of Munc13-4 with perforin was Rab27a-dependent.","method":"Immunofluorescence confocal microscopy of primary NK cells, receptor-specific stimulation, patient cells (Rab27a- and Munc13-4-deficient)","journal":"Blood","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — live-cell and fixed co-localization in primary patient and control cells with defined receptor stimulation conditions; single lab","pmids":["19704116"],"is_preprint":false},{"year":2010,"finding":"Munc13-4 is a limiting factor in platelet secretion and hemostasis. Unc13d(Jinx) platelets lack Munc13-4 and show complete ablation of dense granule release and severe impairment of alpha-granule and lysosome secretion, reduced aggregation, and prolonged tail-bleeding times. The secretion defect is not due to altered SNARE expression or granule biogenesis. Recombinant Munc13-4 added to permeabilized Unc13d(Jinx) platelets rescues secretion. Munc13-4 levels directly correlate with extent of granule release.","method":"Unc13d(Jinx) mouse platelets, granule secretion assays, rescue with recombinant protein in permeabilized cells, tail bleeding time, aggregometry","journal":"Blood","confidence":"High","confidence_rationale":"Tier 1 / Strong — reconstitution with recombinant protein in permeabilized cells, KO mouse model, multiple granule types assessed, dose-response correlation; rigorous multi-method study","pmids":["20435885"],"is_preprint":false},{"year":2011,"finding":"The Munc13-4–Rab27a complex is specifically required for tethering secretory lysosomes at the plasma membrane during degranulation. A non-canonical Rab27a-binding motif in the N-terminus of Munc13-4 was identified; point mutants impairing Rab27a binding fail to rescue degranulation in FHL3 patient CTLs and mast cells silenced for Munc13-4. TIRF microscopy revealed that the complex corrals motile secretory lysosomes beneath the plasma membrane; loss of Rab27a binding abolishes this tethering/docking function while not affecting secretory lysosome maturation.","method":"Mutagenesis of Rab27a-binding motif, complementation assay in FHL3 patient CTLs, mast cell siRNA knockdown, TIRF microscopy","journal":"Blood","confidence":"High","confidence_rationale":"Tier 2 / Strong — mutagenesis combined with TIRF imaging, patient cell complementation, and mast cell rescue; multiple orthogonal methods in single rigorous study","pmids":["21693760"],"is_preprint":false},{"year":2012,"finding":"Munc13-4 binds Ca2+ through its C2A and C2B domains and reconstitutes Ca2+-dependent granule exocytosis in permeable cells (platelets, mast, and neuroendocrine cells) dependent on putative Ca2+-binding residues in both C2A and C2B. Munc13-4 exhibits Ca2+-stimulated SNARE interactions dependent on C2A, and Ca2+-dependent membrane binding dependent on C2B. Munc13-4 stimulates SNARE-dependent liposome fusion in a Ca2+- and C2 domain-dependent manner. Munc13-4 is the first priming factor shown to promote Ca2+-dependent SNARE complex formation and SNARE-mediated liposome fusion.","method":"In vitro Ca2+ binding assay, permeable cell exocytosis assay with mutagenesis of Ca2+-binding residues, SNARE binding assay, liposome fusion reconstitution assay","journal":"The Journal of cell biology","confidence":"High","confidence_rationale":"Tier 1 / Strong — in vitro reconstitution of liposome fusion, Ca2+ binding measurements, mutagenesis, permeable cell assay; multiple orthogonal methods in one rigorous study","pmids":["22508512"],"is_preprint":false},{"year":2012,"finding":"MUNC13-4 is essential for phagosomal maturation and bacterial killing in neutrophils. MUNC13-4-deficient (KO) mouse neutrophils show impaired p22phox-expressing granule trafficking to the plasma membrane, defective extracellular and intracellular ROS production, impaired delivery of azurophilic granules and multivesicular bodies to the phagosome, and markedly impaired intracellular killing of P. aeruginosa. This phagosomal maturation function is RAB27A-independent.","method":"Munc13-4 KO mouse neutrophils, vesicle trafficking assays, ROS measurement, bacterial killing assay, comparison with Rab27a KO","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 2 / Strong — KO mouse model, multiple phenotypic readouts (ROS, phagosome maturation, bacterial killing), RAB27A KO comparison establishing independence","pmids":["23115246"],"is_preprint":false},{"year":2012,"finding":"PIP2 regulates Munc13-4 compartmentalization in NK cells. Granule secretion triggering induces transient Munc13-4 raft recruitment followed by AP-2/clathrin-dependent internalization. PIP5K-gamma silencing impairs granule secretion with increased raft-associated Munc13-4 due to defective AP-2 recruitment, impairing Munc13-4 reinternalization. This Munc13-4 endocytic recycling is required to maintain an intracellular pool necessary for serial NK cell killing.","method":"siRNA silencing of PIP5K-gamma, biochemical fractionation (membrane raft isolation), co-immunoprecipitation, serial killing assay in primary NK cells","journal":"Blood","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — siRNA, fractionation, functional killing assay; single lab, multiple methods","pmids":["22271450"],"is_preprint":false},{"year":2013,"finding":"In mast cells, Rab27b (not Rab27a) acts as a positive regulator of degranulation through its effector Munc13-4. Munc13-4-deficient (Jinx) BMMCs phenocopy Rab27b KO and Rab27a/b double-KO secretory impairment, consistent with Munc13-4 acting downstream of Rab27b in granule exocytosis.","method":"Knockout mouse BMMCs (Rab27a ashen, Rab27b KO, Munc13-4 Jinx, double KO), degranulation assays, pharmacological actin disruption","journal":"The FEBS journal","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple KO mouse models with genetic epistasis; single study but rigorous genetic dissection","pmids":["23281710"],"is_preprint":false},{"year":2014,"finding":"Transcription of UNC13D in cytotoxic lymphocytes is regulated by an intronic enhancer/alternative promoter in intron 1. The FHL3-associated mutation c.118-308C>T disrupts binding of the ETS family transcription factor ELF1 to this conserved intronic sequence, impairing STAT4 and BRG1 (chromatin remodeling complex) recruitment, reducing active histone modifications and diminishing Munc13-4 expression. TCR engagement facilitates STAT4-dependent Munc13-4 expression in naive CD8+ T cells.","method":"Electrophoretic mobility shift assay, chromatin immunoprecipitation, reporter assay, quantitative PCR in patient PBMCs, histone modification analysis","journal":"The Journal of experimental medicine","confidence":"High","confidence_rationale":"Tier 2 / Strong — ChIP, EMSA, reporter assay, patient cells; multiple orthogonal methods establishing transcriptional mechanism","pmids":["24842371"],"is_preprint":false},{"year":2014,"finding":"Rab27a mutations at residues R141, Y159, and S163 selectively disrupt Rab27a interaction with Munc13-4 without impairing Rab27a–melanophilin interaction, identifying a critical binding site for Munc13-4 on Rab27a.","method":"Patient mutation analysis, functional interaction assays in patient cells, protein interaction studies","journal":"The Journal of allergy and clinical immunology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — patient-derived mutations with selective binding disruption established by functional assays; single study","pmids":["25312756"],"is_preprint":false},{"year":2015,"finding":"Munc13-4 binds Rab11a (but not dominant-negative Rab11a) and regulates trafficking and docking of Rab11-positive vesicles at the plasma membrane in neutrophils. A Ca2+-binding-deficient Munc13-4 mutant significantly impairs Rab11 trafficking. Munc13-4-deficient neutrophils show normal endocytosis but impaired Rab11-vesicle trafficking, up-regulation, and retention at the plasma membrane, correlating with deficient NADPH oxidase activation.","method":"TR-FRET binding assay, co-immunoprecipitation, super-resolution microscopy, vesicular dynamics analysis, Munc13-4 KO mouse neutrophils, Ca2+-binding mutant expression","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 2 / Strong — novel TR-FRET assay plus co-IP, super-resolution microscopy, KO neutrophils, mutagenesis; multiple orthogonal methods","pmids":["26637356"],"is_preprint":false},{"year":2015,"finding":"Munc13-4 acts as a Ca2+-dependent tether during platelet secretion. Ca2+-dependent enhancement of SNARE-dependent proteoliposome fusion requires both C2 domains of Munc13-4 and the Ca2+-coordinating aspartate residues of C2B specifically. Munc13-4 clusters PS-containing liposomes in response to Ca2+. Analytical ultracentrifugation shows Munc13-4 is a monomeric prolate ellipsoid with dimensions compatible with bridging two fusing membranes. Dense granules are highly mobile in Munc13-4-null platelets at rest and during stimulation with no stimulation-dependent release, indicating Munc13-4 plays a vesicle-stabilizing/tethering role.","method":"In vitro SNARE-dependent proteoliposome fusion assay, mutagenesis of C2 domain Ca2+-liganding residues, liposome clustering assay, analytical ultracentrifugation, live-cell mepacrine dense granule imaging in Unc13d(Jinx) platelets","journal":"The Biochemical journal","confidence":"High","confidence_rationale":"Tier 1 / Strong — in vitro reconstitution with mutagenesis, liposome assays, structural analysis (AUC), and live-cell imaging in KO platelets; multiple rigorous methods","pmids":["26637270"],"is_preprint":false},{"year":2015,"finding":"Munc13-4 interacts with syntaxin 7 (STX7) and VAMP8, with Ca2+ significantly increasing Munc13-4–STX7 binding. A STX7-binding-deficient Munc13-4 mutant fails to rescue late endosomal maturation defects in Munc13-4-deficient cells. Munc13-4 regulates late endosomal maturation: its deficiency causes enlarged late endosomes and decreased degradative capacity. Munc13-4-KO neutrophils show impaired TLR9-dependent signaling and CD11b up-regulation.","method":"Co-immunoprecipitation, high-resolution and live-cell microscopy, rescue assay with STX7-binding-deficient mutant, late endosome size/function quantification, TLR9 signaling assay in KO neutrophils","journal":"Molecular biology of the cell","confidence":"High","confidence_rationale":"Tier 2 / Strong — co-IP with Ca2+ dependence, mutant rescue, KO cells, multiple functional readouts; rigorous multi-method study","pmids":["26680738"],"is_preprint":false},{"year":2016,"finding":"Rab37, a small GTPase present on mast cell secretory granules, binds Munc13-4 in a GTP-independent manner and forms a Rab27–Munc13-4–Rab37 ternary complex. Rab37 negatively regulates mast cell degranulation; Rab37 knockdown causes hypersecretion that is suppressed by co-knockdown of Rab27a/b or Munc13-4, indicating Rab37 acts through the Rab27–Munc13-4 system.","method":"co-immunoprecipitation, siRNA knockdown, dominant-active mutant overexpression, degranulation assay in RBL-2H3 cells","journal":"Scientific reports","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — co-IP, genetic epistasis via double knockdown, functional assay; single lab","pmids":["26931073"],"is_preprint":false},{"year":2017,"finding":"Munc13-4 functions as a tethering/priming factor and Ca2+ sensor for both heterotypic secretory granule (SG)–plasma membrane and homotypic SG–SG fusion in mast cells. Ca2+ stimulation generates large Munc13-4+/Rab7+/Rab11+ endosomal vacuoles through homotypic SG fusion, dependent on Ca2+ binding to Munc13-4. Munc13-4 promotes Ca2+-stimulated fusion of VAMP8-containing liposomes with both exocytic and endosomal Q-SNARE liposomes, and directly interacts with late endosomal SNARE complexes. Vacuoles are exocytic and mediate secretion.","method":"Ca2+ stimulation live-cell imaging, TIRF microscopy, liposome fusion assay with VAMP8-containing and Q-SNARE liposomes, Ca2+-binding mutants, SNARE co-precipitation","journal":"Molecular biology of the cell","confidence":"High","confidence_rationale":"Tier 1 / Strong — in vitro liposome fusion reconstitution, Ca2+ binding mutants, TIRF imaging, SNARE interaction; multiple orthogonal methods in one study","pmids":["28100639"],"is_preprint":false},{"year":2017,"finding":"Munc13-4 is a Weibel-Palade body (WPB) tethering factor in endothelial cells. Munc13-4 is present on WPBs and its secretagogue-evoked recruitment to WPBs is increased at sites of WPB–plasma membrane contact. Munc13-4 promotes histamine-evoked WPB exocytosis. The S100A10 subunit of the annexin A2–S100A10 complex is a novel Munc13-4 interactor that participates in recruiting Munc13-4 to WPB fusion sites.","method":"Fluorescence microscopy (TIRF), co-immunoprecipitation, siRNA knockdown, von Willebrand factor secretion assay in endothelial cells","journal":"Molecular biology of the cell","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — co-IP for new interaction, TIRF imaging, functional knockdown; single lab, multiple methods","pmids":["28450451"],"is_preprint":false},{"year":2018,"finding":"Munc13-4 regulates a Ca2+-stimulated exosome release pathway in cancer cells. Munc13-4 knockdown eliminates Ca2+-triggered CD63+/CD9+/ALIX+ exosome release; Ca2+-binding-deficient Munc13-4 mutants fail to restore this release. Munc13-4 depletion reduces the size of CD63+ multivesicular bodies (MVBs) in breast carcinoma cells. Munc13-4 uses a Rab11-dependent trafficking pathway to generate MVBs competent for exosome release. Munc13-4 depletion reduces MT1-MMP trafficking to MVBs and extracellular matrix degradation.","method":"siRNA knockdown, Ca2+-binding-deficient mutant rescue, CD63-pHluorin live imaging, MVB size quantification, MT1-MMP trafficking assay, ECM degradation assay","journal":"The Journal of cell biology","confidence":"High","confidence_rationale":"Tier 2 / Strong — live imaging of exosome release, mutant rescue, MVB morphology, multiple functional readouts; multiple orthogonal methods in one rigorous study","pmids":["29930202"],"is_preprint":false},{"year":2018,"finding":"Both C2 domains of Munc13-4 are critical Ca2+ sensors for NK cell degranulation and cytotoxicity. Point mutations in aspartate residues in either C2A or C2B diminish exocytosis, alter Ca2+ sensitivity of fusion pore opening, and impair NK cell cytotoxicity against malignant cells. TIRF microscopy showed these mutations alter Ca2+ dependence and frequency of single-granule fusion events.","method":"Site-directed mutagenesis of C2A/C2B Ca2+-coordinating aspartates, expression in primary mouse NK cells and RBL mast cells, TIRF single-granule imaging, cytotoxicity assay","journal":"Journal of immunology","confidence":"High","confidence_rationale":"Tier 1 / Strong — mutagenesis of active-site residues with single-granule TIRF imaging and cytotoxicity assays in primary NK cells; multiple orthogonal methods","pmids":["29884704"],"is_preprint":false},{"year":2018,"finding":"Platelet-specific deletion of Munc13-4 ablates dense granule release and indirectly impairs alpha-granule exocytosis (Munc13-2 has no exocytic role in platelets even in absence of Munc13-4). Munc13-4 acts as a rate-limiting factor in thrombus formation in vitro and in vivo. Munc13-4 expression in platelets dose-dependently regulates venous bleeding time and arterial thrombosis. Platelet-specific Munc13-4 KO reduces airway hyper-responsiveness and eosinophilic inflammation in allergic model.","method":"Conditional Munc13-4 KO mice (platelet-specific), granule secretion assays, flow chamber thrombosis assay, in vivo bleeding and thrombosis models, airway inflammation model","journal":"Haematologica","confidence":"High","confidence_rationale":"Tier 2 / Strong — conditional KO mouse model with multiple in vitro and in vivo functional readouts; rigorous genetic study","pmids":["29674495"],"is_preprint":false},{"year":2018,"finding":"An intronic UNC13D variant (c.117+143A>G) disrupts NF-κB binding to a functional transcriptional enhancer in intron 1, reducing UNC13D transcript levels in patient PBMCs and impairing NK cell degranulation. This was demonstrated by EMSA showing disrupted NF-κB binding and in vitro transcriptional enhancer assay showing reduced activity.","method":"EMSA, in vitro transcriptional enhancer assay, qPCR of patient PBMCs, NK cell degranulation assay, partial UNC13D knockdown","journal":"Arthritis & rheumatology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — EMSA and reporter assay define molecular mechanism; patient-derived cells confirm functional consequence; single lab","pmids":["29409136"],"is_preprint":false},{"year":2019,"finding":"UNC13D-deficient cells show impaired endosomal trafficking, defective endocytic flux, and increased autophagic flux. The defective endosomal phenotype is rescued by UNC13D but not by its STX7-binding-deficient mutant. The increased autophagy in UNC13D-deficient cells is driven at least in part by TFEB-mediated upregulation of autophagic and lysosomal genes including Atg9b; TFEB knockdown reduces Atg9b and autophagy. UNC13D upregulation corrects endolysosomal trafficking and reduces autophagosome accumulation in a cystinosis cell model.","method":"KO cells, rescue with WT vs. STX7-binding mutant, autophagy flux assays, TFEB knockdown, biochemical and microscopy methods, cystinosis cell model","journal":"Autophagy","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — KO cells with mutant rescue, TFEB epistasis, multiple readouts; single lab","pmids":["30892133"],"is_preprint":false},{"year":2020,"finding":"UNC13D encodes two isoforms with distinct N-termini driven by an alternative promoter/TSS in intron 1. The alternative (lymphocyte/platelet-predominant) isoform has a unique N-terminus but does not differ from the conventional isoform in Munc13-4 localization, trafficking to the immunological synapse, or ability to restore exocytosis in FHL3 patient T cells. Both isoforms equivalently rescue degranulation.","method":"Isoform-specific antibodies, subcellular localization (imaging), complementation/rescue assay in FHL3 patient T cells, ectopic expression","journal":"Frontiers in immunology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — isoform-specific antibodies with patient cell complementation; single lab, multiple methods","pmids":["32582217"],"is_preprint":false},{"year":2022,"finding":"UNC13D co-localizes with STING on the endoplasmic reticulum and inhibits STING oligomerization. Knockdown or knockout of UNC13D promotes IFN-β production in response to DNA viruses (but not RNA viruses) and increases basal proinflammatory cytokine levels, effects abolished by a STING inhibitor. The domains on both UNC13D and STING mediating their interaction were mapped.","method":"Co-localization (fluorescence microscopy), co-immunoprecipitation/interaction mapping, UNC13D knockdown and knockout, IFN-β reporter/ELISA, STING inhibitor rescue","journal":"EMBO reports","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — co-IP with domain mapping, KO cells, functional innate immune signaling assays; single lab, multiple methods","pmids":["36125406"],"is_preprint":false},{"year":2024,"finding":"UNC13D regulates pancreatic cancer cell migration by coupling exocytosis of recycling endosomes with focal adhesion turnover through the RAB11–UNC13D–FAK axis. UNC13D directly interacts with the FERM domain of FAK and regulates FAK phosphorylation in a calcium-dependent manner. Immunoprecipitation confirmed the RAB11–UNC13D–FAK complex in endosomes during integrin recycling.","method":"Co-immunoprecipitation, immunocytochemistry, migration assays, FAK phosphorylation assay, domain interaction mapping (FERM domain)","journal":"Journal of translational medicine","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — co-IP with domain mapping, functional migration assay, Ca2+-dependent regulation; single lab","pmids":["39210440"],"is_preprint":false},{"year":2025,"finding":"Munc13-4 collaborates with HRS, Rab27, and SNAREs to facilitate PD-L1 sorting and secretion via exosomes in tumor cells, mediating immune evasion. PD-L1 sorting relies on a ternary Munc13-4–PD-L1–HRS complex regulated by IFNγ signaling. Cryo-EM analysis of the Munc13-4–Rab27a complex provided structural insights into exosome secretion. A designed peptide disrupting the Munc13-4–PD-L1 interaction inhibits PD-L1 exosomal sorting and enhances anti-tumor immunity.","method":"Cryo-EM structure of Munc13-4–Rab27a complex, co-immunoprecipitation (ternary complex), Munc13-4 deletion in tumor cells, exosome PD-L1 assay, designed peptide inhibition, in vivo tumor models","journal":"Nature communications","confidence":"High","confidence_rationale":"Tier 1 / Strong — cryo-EM structure, ternary complex co-IP, functional tumor/immune assays, therapeutic peptide validation; multiple rigorous orthogonal methods","pmids":["41083534"],"is_preprint":false},{"year":2025,"finding":"Munc13-4 is a central regulator of crinophagy (secretory granule–lysosome fusion) in mammalian endocrine cells. siRNA screening identified Munc13-4 as required for SG-lysosome merge along with Rab27A, VAMP2, PLEKHM1, HOPS subunits, and SNAREs STX7, STX8, VTI1B. SG-lysosome fusion is regulated by local or global calcium through binding and activation of Munc13-4.","method":"siRNA screen with live-cell SG-lysosome merge assay, Ca2+ manipulation, identification of required components","journal":"Research square (preprint)","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — siRNA screen plus live-cell assay; preprint, not yet peer-reviewed; single study","pmids":["40951263"],"is_preprint":true},{"year":2026,"finding":"Small-molecule ENDOtollins (ENDOs) that inhibit the Munc13-4–STX7 interaction reduce endolysosomal flux, impair endosomal TLR3/7/9 signaling in dendritic cells and ERK signaling in neutrophils in response to endosomal (but not plasma membrane) TLR ligands, and reduce CpG-induced systemic inflammation in vivo. This establishes the Munc13-4–STX7 interaction as mechanistically required for endosomal TLR signaling.","method":"High-throughput compound screen, orthogonal cell-based validation, endolysosomal flux assay, TLR signaling assays, in vivo CpG inflammation model, chemical optimization","journal":"Nature chemical biology","confidence":"High","confidence_rationale":"Tier 1 / Strong — pharmacological target validation with small molecules, in vitro mechanistic assays, and in vivo model; multiple orthogonal methods establishing Munc13-4–STX7 as required for endosomal TLR pathway","pmids":["41942734"],"is_preprint":false},{"year":2011,"finding":"A C-terminal C2B domain truncation mutation in Munc13-4 (p.Arg899X; Munc13-4(1-899)) correctly targets to CD63+ secretory lysosomes but shows reduced stability, uncoupled dynamic turnover on granule membrane, and fails to rescue degranulation in cells with silenced endogenous Munc13-4. This demonstrates that the C-terminal C2B domain is essential for Munc13-4 function.","method":"Ectopic expression of truncation mutant in patient/silenced cells, CD63 co-localization, protein stability assay, degranulation rescue assay","journal":"Pediatric blood & cancer","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — functional domain mapping via patient-derived mutation, rescue assay, localization; single lab","pmids":["21755595"],"is_preprint":false},{"year":2018,"finding":"In airway epithelial cells, Munc13-4 (but not Munc13-2) is specifically recruited to the plasma membrane and increases its interaction with syntaxin 2 in response to human neutrophil elastase (hNE) stimulation. Munc13-4 siRNA knockdown reduces hNE-stimulated MUC5AC secretion while increasing intracellular MUC5AC retention, indicating Munc13-4 mediates hNE-stimulated airway mucin hypersecretion via syntaxin 2.","method":"Co-immunoprecipitation (Munc13-4–syntaxin 2), siRNA knockdown, ELISA for MUC5AC secretion, immunofluorescence, Western blotting","journal":"Molecular medicine reports","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single co-IP and siRNA in cell lines; single lab, limited mechanistic depth","pmids":["29767240"],"is_preprint":false},{"year":2020,"finding":"Munc13-4 is required for TNF production (not just secretion) in activated RBL-2H3 mast cells. Munc13-4 KO cells show absent antigen/IgE-induced TNF production, restored by Munc13-4 re-expression. A TNF receptor antagonist blocks TNF production without inhibiting release, revealing a TNF autocrine feed-back loop that requires Munc13-4.","method":"Munc13-4 KO cell line, rescue by re-expression, ELISA for TNF secretion and intracellular levels, TNF receptor antagonist","journal":"Inflammation","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — KO with rescue and pharmacological dissection; single lab","pmids":["31897916"],"is_preprint":false}],"current_model":"Munc13-4 (UNC13D) is a dual C2-domain Ca2+ sensor and vesicle priming/tethering factor that, upon Ca2+ elevation, binds phospholipids and SNARE proteins (syntaxin 7/VAMP8 at late endosomes; exocytic SNAREs at the plasma membrane) to promote SNARE-dependent membrane fusion; it is recruited to secretory lysosomes, dense-core granules, multivesicular bodies, and Weibel-Palade bodies through direct GTP-Rab27a/b and Rab11 interactions, where it tethers vesicles at the plasma membrane and primes them for Ca2+-triggered exocytosis across hematopoietic and non-hematopoietic cells, while also regulating late endosomal maturation, phagosomal function, TLR9/endosomal innate immune signaling, exosomal PD-L1 secretion, and autophagy via a TFEB-dependent pathway."},"narrative":{"mechanistic_narrative":"Munc13-4 (UNC13D) is a Ca2+-dependent vesicle tethering and priming factor that drives SNARE-mediated membrane fusion in regulated secretory and endolysosomal pathways across hematopoietic and non-hematopoietic cells [PMID:14622600, PMID:22508512]. It is essential for the priming step of cytolytic granule secretion in cytotoxic lymphocytes that precedes membrane fusion, and loss-of-function mutations in UNC13D cause familial hemophagocytic lymphohistiocytosis type 3 (FHL3) [PMID:14622600]. Munc13-4 senses Ca2+ through its tandem C2A and C2B domains: C2A supports Ca2+-stimulated SNARE binding while C2B drives Ca2+-dependent membrane binding, and together these domains enable Munc13-4 to promote Ca2+-triggered SNARE complex formation and SNARE-dependent liposome fusion [PMID:22508512, PMID:29884704]. As a monomeric prolate ellipsoid able to bridge two membranes, it acts as a Ca2+-dependent tether that corrals motile secretory vesicles beneath the plasma membrane and clusters acidic-phospholipid membranes [PMID:26637270, PMID:21693760]. Recruitment to target organelles occurs through direct binding to GTP-loaded Rab27a/Rab27b via a non-canonical N-terminal Rab27-binding motif, and through Rab11, linking Munc13-4 to dense-core granules, secretory lysosomes, and recycling endosomes [PMID:14699162, PMID:21693760, PMID:26637356]. Beyond exocytosis, Munc13-4 binds the endosomal SNARE syntaxin 7 (and VAMP8) to govern late endosomal maturation and endosomal TLR signaling, a function pharmacologically validated as required for endosomal TLR3/7/9 responses [PMID:26680738, PMID:41942734]. This broad fusion-machinery role underlies its requirement in cytotoxic lymphocyte killing, platelet dense/alpha-granule release and hemostasis, neutrophil granule exocytosis and phagosomal maturation, mast cell degranulation, Weibel-Palade body exocytosis, and tumor-associated exosomal PD-L1 secretion [PMID:20435885, PMID:23115246, PMID:28450451, PMID:41083534].","teleology":[{"year":2003,"claim":"Established Munc13-4 as the priming factor whose loss causes a human immunodeficiency, defining its role in regulated secretion and placing it upstream of membrane fusion in cytotoxic granule exocytosis.","evidence":"Patient UNC13D mutation analysis, tagged-protein localization, and exocytosis assays in cytotoxic T lymphocytes","pmids":["14622600"],"confidence":"High","gaps":["Molecular fusion mechanism not defined at this stage","No biochemical reconstitution of the priming activity"]},{"year":2003,"claim":"Identified Munc13-4 as the direct effector of GTP-Rab27, explaining how the secretory machinery is recruited to and activated at granules.","evidence":"Affinity purification, in vitro recombinant binding assay, and permeabilized platelet secretion rescue","pmids":["14699162"],"confidence":"High","gaps":["Binding interface on Munc13-4 not mapped","Did not establish how Rab27 binding couples to fusion"]},{"year":2006,"claim":"Mapped specific Munc13-4 residues required for stable Rab27a complex formation, linking disease mutations to loss of effector binding.","evidence":"Mammalian two-hybrid analysis of the L403P missense mutant","pmids":["16278825"],"confidence":"Medium","gaps":["Two-hybrid only; no structural or biophysical binding measurement","Functional secretion consequence not directly tested here"]},{"year":2008,"claim":"Extended Munc13-4 function beyond lymphocytes to neutrophil and mast cell granule exocytosis and identified Ca2+-regulated membrane recruitment and a Doc2alpha partner.","evidence":"Cell fractionation, immunofluorescence, siRNA/KO mouse cells, phospholipid binding, and reciprocal co-IP","pmids":["18453599","18354201","18939952"],"confidence":"High","gaps":["Precise SNARE machinery engaged not yet defined","Relative contribution of Ca2+ vs Rab recruitment not resolved"]},{"year":2009,"claim":"Showed receptor-specific, Rab27a-dependent recruitment of Munc13-4 to lytic granules, revealing signal-dependent control of where the machinery assembles.","evidence":"Confocal colocalization in primary and patient-derived NK cells with defined receptor stimulation","pmids":["19704116"],"confidence":"Medium","gaps":["Mechanism of differential receptor coupling unknown","Single-lab, imaging-based"]},{"year":2011,"claim":"Defined the Munc13-4-Rab27a complex as a tether that corrals motile secretory lysosomes at the plasma membrane and mapped a non-canonical Rab27a-binding motif required for degranulation.","evidence":"Rab27a-binding motif mutagenesis, FHL3 patient CTL complementation, mast cell rescue, and TIRF imaging; C-terminal C2B truncation analysis","pmids":["21693760","21755595"],"confidence":"High","gaps":["Tethering vs priming activities not biochemically separated here","Structural basis of motif recognition not solved"]},{"year":2012,"claim":"Demonstrated biochemically that Munc13-4 is a Ca2+ sensor that promotes Ca2+-dependent SNARE complex formation and SNARE-mediated liposome fusion via its C2 domains, the first such priming factor activity reconstituted in vitro.","evidence":"In vitro Ca2+ binding, C2 Ca2+-residue mutagenesis, SNARE binding, liposome fusion reconstitution, and permeable cell exocytosis assays","pmids":["22508512"],"confidence":"High","gaps":["Identity of physiological SNAREs at each compartment not fully resolved","Stoichiometry of fusion machinery not defined"]},{"year":2012,"claim":"Revealed Rab27a-independent Munc13-4 functions in phagosomal maturation/bacterial killing and PIP2/AP-2-dependent endocytic recycling needed to sustain serial killing.","evidence":"Munc13-4 KO mouse neutrophils with Rab27a KO comparison; PIP5K-gamma silencing, raft fractionation, and serial killing assays","pmids":["23115246","22271450"],"confidence":"High","gaps":["How Munc13-4 is recruited independently of Rab27a not defined","Recycling-pathway role rests on single-lab Medium evidence"]},{"year":2013,"claim":"Established genetic epistasis placing Munc13-4 downstream of Rab27b (not only Rab27a) in mast cell degranulation.","evidence":"Multiple KO mouse BMMC models with double-knockout degranulation assays","pmids":["23281710"],"confidence":"Medium","gaps":["Tissue-specific Rab27 isoform preference mechanism unclear","Single study"]},{"year":2014,"claim":"Defined transcriptional control of UNC13D through an intronic enhancer/alternative promoter, showing how non-coding disease variants reduce Munc13-4 expression.","evidence":"EMSA, ChIP, reporter assays, and patient PBMC qPCR identifying ELF1/STAT4/BRG1 regulation and the c.118-308C>T variant; complementary Rab27a-side interaction mapping","pmids":["24842371","25312756"],"confidence":"High","gaps":["Full set of regulatory inputs not enumerated","Rab27a-side mapping is Medium-confidence patient-mutation work"]},{"year":2015,"claim":"Expanded the partner repertoire to Rab11 and the endosomal SNARE syntaxin 7/VAMP8, establishing Munc13-4 roles in recycling-endosome trafficking and late endosomal maturation distinct from classical exocytosis.","evidence":"TR-FRET/co-IP binding, super-resolution and live-cell imaging, KO neutrophils, Ca2+-binding and STX7-binding mutant rescue; AUC and proteoliposome fusion","pmids":["26637356","26637270","26680738"],"confidence":"High","gaps":["How a single Munc13-4 selects among Rab11/Rab27/SNARE partners not resolved","Structural basis of monomeric membrane bridging inferred from AUC dimensions"]},{"year":2016,"claim":"Identified a Rab27-Munc13-4-Rab37 ternary complex through which Rab37 negatively regulates degranulation, adding a brake to the priming machinery.","evidence":"Co-IP, siRNA epistasis, and degranulation assays in RBL-2H3 cells","pmids":["26931073"],"confidence":"Medium","gaps":["GTP-independent Rab37 binding mechanism unexplained","Single-lab"]},{"year":2017,"claim":"Showed Munc13-4 catalyzes both heterotypic granule-plasma membrane and homotypic granule-granule fusion and engages late endosomal SNARE complexes, broadening its fusion-machinery role; also defined it as a Weibel-Palade body tether in endothelium.","evidence":"Liposome fusion with exocytic and endosomal Q-SNAREs, Ca2+-binding mutants, TIRF imaging; TIRF/co-IP and VWF secretion assays with S100A10","pmids":["28100639","28450451"],"confidence":"High","gaps":["Recruitment determinants in endothelial cells (S100A10 role) Medium-confidence","Switch between homotypic and heterotypic fusion not mechanistically defined"]},{"year":2018,"claim":"Confirmed both C2 domains as functionally required Ca2+ sensors controlling fusion-pore Ca2+ sensitivity, and established Munc13-4 as a rate-limiting determinant of platelet-driven thrombosis and inflammation in vivo.","evidence":"C2A/C2B aspartate mutagenesis with single-granule TIRF and cytotoxicity in NK cells; platelet-specific conditional KO with thrombosis, bleeding, and airway inflammation models","pmids":["29884704","29674495"],"confidence":"High","gaps":["Quantitative Ca2+-sensing model across cell types incomplete","Indirect alpha-granule effect mechanism not resolved"]},{"year":2018,"claim":"Extended UNC13D dysregulation to additional non-coding disease variants and to autocrine TNF production in mast cells.","evidence":"EMSA/enhancer reporter and patient PBMC analysis of the NF-kB-disrupting c.117+143A>G variant; KO/rescue and TNF receptor antagonist in RBL-2H3 cells","pmids":["29409136","31897916"],"confidence":"Medium","gaps":["How a secretion factor controls cytokine production not mechanistically defined","Single-lab studies"]},{"year":2019,"claim":"Linked Munc13-4 endosomal function to autophagy regulation via a TFEB-dependent program, connecting endolysosomal trafficking to lysosomal biogenesis.","evidence":"KO cells with WT vs STX7-binding-mutant rescue, autophagy flux assays, TFEB knockdown, and a cystinosis cell model","pmids":["30892133"],"confidence":"Medium","gaps":["Direct vs indirect link to TFEB unresolved","Single-lab"]},{"year":2020,"claim":"Resolved the functional significance of UNC13D isoforms, showing the alternative N-terminal isoform is interchangeable for localization and exocytic rescue.","evidence":"Isoform-specific antibodies and FHL3 patient T cell complementation","pmids":["32582217"],"confidence":"Medium","gaps":["Possible isoform-specific functions outside exocytosis untested","Single-lab"]},{"year":2018,"claim":"Demonstrated a Munc13-4-dependent Ca2+-stimulated exosome release pathway controlling MVB biogenesis and tumor matrix degradation through Rab11-dependent trafficking.","evidence":"siRNA knockdown, Ca2+-binding mutant rescue, CD63-pHluorin imaging, MVB morphology, MT1-MMP trafficking and ECM degradation assays","pmids":["29930202"],"confidence":"High","gaps":["How Munc13-4 directs MVB-versus-secretory fates not defined","Cancer-cell specificity of the pathway not established"]},{"year":2022,"claim":"Uncovered a non-secretory regulatory role at the ER, where UNC13D restrains STING oligomerization and DNA-sensing innate immune signaling.","evidence":"Co-localization, co-IP/domain mapping, KO/KD cells, IFN-beta readouts, and STING inhibitor rescue","pmids":["36125406"],"confidence":"Medium","gaps":["How a fusion factor localizes to ER and inhibits STING unclear","Single-lab"]},{"year":2024,"claim":"Defined a RAB11-UNC13D-FAK axis coupling recycling-endosome exocytosis to focal adhesion turnover and cancer cell migration.","evidence":"Co-IP/FERM-domain mapping, Ca2+-dependent FAK phosphorylation, and migration assays","pmids":["39210440"],"confidence":"Medium","gaps":["Direct FAK interaction needs structural validation","Single-lab"]},{"year":2025,"claim":"Provided structural insight into the Munc13-4-Rab27a complex and defined a Munc13-4-PD-L1-HRS ternary complex driving exosomal PD-L1 secretion and immune evasion, validated by a disruptive peptide.","evidence":"Cryo-EM of Munc13-4-Rab27a, ternary co-IP, tumor-cell deletion, exosome PD-L1 assays, peptide inhibition, and in vivo tumor models","pmids":["41083534"],"confidence":"High","gaps":["Atomic interface of PD-L1/HRS engagement not resolved","Generality across tumor types untested"]},{"year":2025,"claim":"Implicated Munc13-4 as a central regulator of crinophagy via secretory granule-lysosome fusion in endocrine cells.","evidence":"siRNA screen with live-cell SG-lysosome merge assay and Ca2+ manipulation (preprint)","pmids":["40951263"],"confidence":"Medium","gaps":["Preprint, not yet peer-reviewed","Direct binding to the identified HOPS/SNARE machinery not biochemically shown"]},{"year":2026,"claim":"Pharmacologically validated the Munc13-4-STX7 interaction as mechanistically required for endolysosomal flux and endosomal TLR signaling, establishing it as a druggable inflammatory node.","evidence":"Small-molecule (ENDOtollin) inhibitors, endolysosomal flux and TLR signaling assays, and an in vivo CpG inflammation model","pmids":["41942734"],"confidence":"High","gaps":["Selectivity of Munc13-4-STX7 disruption versus other SNARE interactions not fully mapped","Long-term consequences of chronic inhibition unknown"]},{"year":null,"claim":"How a single Munc13-4 protein integrates competing Rab (Rab27a/b, Rab11, Rab37) and SNARE (exocytic vs syntaxin 7/VAMP8) partners to select among exocytosis, endosomal maturation, autophagy, and ER-based STING regulation in a cell-type- and signal-specific manner remains unresolved.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No unified structural/biophysical model of partner selection","Mechanism of compartment-specific recruitment incompletely defined","Non-secretory ER/STING role mechanistically isolated"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0140299","term_label":"molecular sensor activity","supporting_discovery_ids":[9,16,22]},{"term_id":"GO:0008289","term_label":"lipid binding","supporting_discovery_ids":[3,9,16]},{"term_id":"GO:0060090","term_label":"molecular adaptor activity","supporting_discovery_ids":[8,16,19]},{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[1,9,17]}],"localization":[{"term_id":"GO:0005829","term_label":"cytosol","supporting_discovery_ids":[3]},{"term_id":"GO:0005886","term_label":"plasma membrane","supporting_discovery_ids":[3,8,33]},{"term_id":"GO:0005768","term_label":"endosome","supporting_discovery_ids":[15,17,25]},{"term_id":"GO:0005764","term_label":"lysosome","supporting_discovery_ids":[4,8,30]},{"term_id":"GO:0031410","term_label":"cytoplasmic vesicle","supporting_discovery_ids":[0,1,20]},{"term_id":"GO:0005783","term_label":"endoplasmic reticulum","supporting_discovery_ids":[27]}],"pathway":[{"term_id":"R-HSA-5653656","term_label":"Vesicle-mediated transport","supporting_discovery_ids":[0,7,9]},{"term_id":"R-HSA-168256","term_label":"Immune System","supporting_discovery_ids":[0,10,31]},{"term_id":"R-HSA-109582","term_label":"Hemostasis","supporting_discovery_ids":[7,23]},{"term_id":"R-HSA-9612973","term_label":"Autophagy","supporting_discovery_ids":[25]},{"term_id":"R-HSA-9609507","term_label":"Protein localization","supporting_discovery_ids":[15,17,21]}],"complexes":["Munc13-4-Rab27a complex","Rab27-Munc13-4-Rab37 ternary complex","Munc13-4-PD-L1-HRS complex","RAB11-UNC13D-FAK complex"],"partners":["RAB27A","RAB27B","RAB11A","STX7","VAMP8","DOC2A","STING1","PTK2"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q70J99","full_name":"Protein unc-13 homolog D","aliases":["Munc13-4"],"length_aa":1090,"mass_kda":123.3,"function":"Plays a role in cytotoxic granule exocytosis in lymphocytes. Required for both granule maturation and granule docking and priming at the immunologic synapse. Regulates assembly of recycling and late endosomal structures, leading to the formation of an endosomal exocytic compartment that fuses with perforin-containing granules at the immunologic synapse and licences them for exocytosis. Regulates Ca(2+)-dependent secretory lysosome exocytosis in mast cells","subcellular_location":"Cytoplasm; Membrane; Late endosome; Recycling endosome; Lysosome","url":"https://www.uniprot.org/uniprotkb/Q70J99/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/UNC13D","classification":"Not Classified","n_dependent_lines":20,"n_total_lines":1208,"dependency_fraction":0.016556291390728478},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/UNC13D","total_profiled":1310},"omim":[{"mim_id":"619547","title":"RAB15, MEMBER RAS ONCOGENE FAMILY; RAB15","url":"https://www.omim.org/entry/619547"},{"mim_id":"613101","title":"HEMOPHAGOCYTIC LYMPHOHISTIOCYTOSIS, FAMILIAL, 5, WITH OR WITHOUT MICROVILLUS INCLUSION DISEASE; FHL5","url":"https://www.omim.org/entry/613101"},{"mim_id":"608898","title":"HEMOPHAGOCYTIC LYMPHOHISTIOCYTOSIS, FAMILIAL, 3; FHL3","url":"https://www.omim.org/entry/608898"},{"mim_id":"608897","title":"UNC13 HOMOLOG D; UNC13D","url":"https://www.omim.org/entry/608897"},{"mim_id":"605014","title":"SYNTAXIN 11; STX11","url":"https://www.omim.org/entry/605014"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Supported","locations":[{"location":"Cytosol","reliability":"Supported"},{"location":"Vesicles","reliability":"Additional"}],"tissue_specificity":"Tissue enhanced","tissue_distribution":"Detected in many","driving_tissues":[{"tissue":"bone marrow","ntpm":66.9},{"tissue":"lymphoid tissue","ntpm":65.9}],"url":"https://www.proteinatlas.org/search/UNC13D"},"hgnc":{"alias_symbol":["Munc13-4"],"prev_symbol":[]},"alphafold":{"accession":"Q70J99","domains":[{"cath_id":"-","chopping":"366-452","consensus_level":"medium","plddt":90.8063,"start":366,"end":452},{"cath_id":"-","chopping":"458-584","consensus_level":"high","plddt":89.0755,"start":458,"end":584},{"cath_id":"1.10.357.50","chopping":"594-760","consensus_level":"high","plddt":90.1453,"start":594,"end":760},{"cath_id":"1.20.58,1.20.1280","chopping":"782-886","consensus_level":"high","plddt":90.3887,"start":782,"end":886},{"cath_id":"2.60.40.150","chopping":"903-1084","consensus_level":"high","plddt":88.1184,"start":903,"end":1084}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q70J99","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q70J99-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q70J99-F1-predicted_aligned_error_v6.png","plddt_mean":84.88},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=UNC13D","jax_strain_url":"https://www.jax.org/strain/search?query=UNC13D"},"sequence":{"accession":"Q70J99","fasta_url":"https://rest.uniprot.org/uniprotkb/Q70J99.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q70J99/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q70J99"}},"corpus_meta":[{"pmid":"14622600","id":"PMC_14622600","title":"Munc13-4 is essential for cytolytic granules fusion and is mutated in a form of familial hemophagocytic lymphohistiocytosis (FHL3).","date":"2003","source":"Cell","url":"https://pubmed.ncbi.nlm.nih.gov/14622600","citation_count":694,"is_preprint":false},{"pmid":"21881043","id":"PMC_21881043","title":"Hypomorphic mutations in PRF1, MUNC13-4, and STXBP2 are associated with adult-onset familial HLH.","date":"2011","source":"Blood","url":"https://pubmed.ncbi.nlm.nih.gov/21881043","citation_count":321,"is_preprint":false},{"pmid":"16278825","id":"PMC_16278825","title":"Mutation spectrum in children with primary hemophagocytic lymphohistiocytosis: molecular and functional analyses of PRF1, UNC13D, STX11, and RAB27A.","date":"2006","source":"Human mutation","url":"https://pubmed.ncbi.nlm.nih.gov/16278825","citation_count":225,"is_preprint":false},{"pmid":"29930202","id":"PMC_29930202","title":"A Ca2+-stimulated exosome release pathway in cancer cells is regulated by Munc13-4.","date":"2018","source":"The Journal of cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/29930202","citation_count":191,"is_preprint":false},{"pmid":"14699162","id":"PMC_14699162","title":"Munc13-4 is a GTP-Rab27-binding protein regulating dense core granule secretion in platelets.","date":"2003","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/14699162","citation_count":163,"is_preprint":false},{"pmid":"17420270","id":"PMC_17420270","title":"Jinx, an MCMV susceptibility phenotype caused by disruption of Unc13d: a mouse model of type 3 familial hemophagocytic lymphohistiocytosis.","date":"2007","source":"The Journal of experimental medicine","url":"https://pubmed.ncbi.nlm.nih.gov/17420270","citation_count":148,"is_preprint":false},{"pmid":"18759271","id":"PMC_18759271","title":"Macrophage activation syndrome in patients with systemic juvenile idiopathic arthritis is associated with MUNC13-4 polymorphisms.","date":"2008","source":"Arthritis and rheumatism","url":"https://pubmed.ncbi.nlm.nih.gov/18759271","citation_count":141,"is_preprint":false},{"pmid":"16778144","id":"PMC_16778144","title":"Analysis of natural killer-cell function in familial hemophagocytic lymphohistiocytosis (FHL): defective CD107a surface expression heralds Munc13-4 defect and discriminates between genetic subtypes of the disease.","date":"2006","source":"Blood","url":"https://pubmed.ncbi.nlm.nih.gov/16778144","citation_count":137,"is_preprint":false},{"pmid":"20435885","id":"PMC_20435885","title":"Munc13-4 is a limiting factor in the pathway required for platelet granule release and hemostasis.","date":"2010","source":"Blood","url":"https://pubmed.ncbi.nlm.nih.gov/20435885","citation_count":105,"is_preprint":false},{"pmid":"21693760","id":"PMC_21693760","title":"The munc13-4-rab27 complex is specifically required for tethering secretory lysosomes at the plasma membrane.","date":"2011","source":"Blood","url":"https://pubmed.ncbi.nlm.nih.gov/21693760","citation_count":104,"is_preprint":false},{"pmid":"20823128","id":"PMC_20823128","title":"Atypical familial hemophagocytic lymphohistiocytosis due to mutations in UNC13D and STXBP2 overlaps with primary immunodeficiency diseases.","date":"2010","source":"Haematologica","url":"https://pubmed.ncbi.nlm.nih.gov/20823128","citation_count":102,"is_preprint":false},{"pmid":"21931115","id":"PMC_21931115","title":"Familial hemophagocytic lymphohistiocytosis type 3 (FHL3) caused by deep intronic mutation and inversion in UNC13D.","date":"2011","source":"Blood","url":"https://pubmed.ncbi.nlm.nih.gov/21931115","citation_count":99,"is_preprint":false},{"pmid":"19704116","id":"PMC_19704116","title":"Different NK cell-activating receptors preferentially recruit Rab27a or Munc13-4 to perforin-containing granules for cytotoxicity.","date":"2009","source":"Blood","url":"https://pubmed.ncbi.nlm.nih.gov/19704116","citation_count":85,"is_preprint":false},{"pmid":"18240215","id":"PMC_18240215","title":"Mutations of the hemophagocytic lymphohistiocytosis-associated gene UNC13D in a patient with systemic juvenile idiopathic arthritis.","date":"2008","source":"Arthritis and rheumatism","url":"https://pubmed.ncbi.nlm.nih.gov/18240215","citation_count":83,"is_preprint":false},{"pmid":"22508512","id":"PMC_22508512","title":"Munc13-4 reconstitutes calcium-dependent SNARE-mediated membrane fusion.","date":"2012","source":"The Journal of cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/22508512","citation_count":78,"is_preprint":false},{"pmid":"18710388","id":"PMC_18710388","title":"Characterization of PRF1, STX11 and UNC13D genotype-phenotype correlations in familial hemophagocytic lymphohistiocytosis.","date":"2008","source":"British journal of haematology","url":"https://pubmed.ncbi.nlm.nih.gov/18710388","citation_count":73,"is_preprint":false},{"pmid":"18939952","id":"PMC_18939952","title":"The Rab27a effectors JFC1/Slp1 and Munc13-4 regulate exocytosis of neutrophil granules.","date":"2008","source":"Traffic (Copenhagen, Denmark)","url":"https://pubmed.ncbi.nlm.nih.gov/18939952","citation_count":72,"is_preprint":false},{"pmid":"16825436","id":"PMC_16825436","title":"Novel Munc13-4 mutations in children and young adult patients with haemophagocytic lymphohistiocytosis.","date":"2006","source":"Journal of medical genetics","url":"https://pubmed.ncbi.nlm.nih.gov/16825436","citation_count":68,"is_preprint":false},{"pmid":"23281710","id":"PMC_23281710","title":"Distinct and opposing roles for Rab27a/Mlph/MyoVa and Rab27b/Munc13-4 in mast cell secretion.","date":"2013","source":"The FEBS journal","url":"https://pubmed.ncbi.nlm.nih.gov/23281710","citation_count":62,"is_preprint":false},{"pmid":"26637356","id":"PMC_26637356","title":"Munc13-4 Is a Rab11-binding Protein That Regulates Rab11-positive Vesicle Trafficking and Docking at the Plasma Membrane.","date":"2015","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/26637356","citation_count":60,"is_preprint":false},{"pmid":"18453599","id":"PMC_18453599","title":"Munc13-4 regulates granule secretion in human neutrophils.","date":"2008","source":"Journal of immunology (Baltimore, Md. : 1950)","url":"https://pubmed.ncbi.nlm.nih.gov/18453599","citation_count":58,"is_preprint":false},{"pmid":"15466010","id":"PMC_15466010","title":"Identification of novel MUNC13-4 mutations in familial haemophagocytic lymphohistiocytosis and functional analysis of MUNC13-4-deficient cytotoxic T lymphocytes.","date":"2004","source":"Journal of medical genetics","url":"https://pubmed.ncbi.nlm.nih.gov/15466010","citation_count":53,"is_preprint":false},{"pmid":"17993578","id":"PMC_17993578","title":"Spectrum, and clinical and functional implications of UNC13D mutations in familial haemophagocytic lymphohistiocytosis.","date":"2007","source":"Journal of medical genetics","url":"https://pubmed.ncbi.nlm.nih.gov/17993578","citation_count":49,"is_preprint":false},{"pmid":"20015888","id":"PMC_20015888","title":"UNC13D is the predominant causative gene with recurrent splicing mutations in Korean patients with familial hemophagocytic lymphohistiocytosis.","date":"2009","source":"Haematologica","url":"https://pubmed.ncbi.nlm.nih.gov/20015888","citation_count":47,"is_preprint":false},{"pmid":"18354201","id":"PMC_18354201","title":"Doc2 alpha and Munc13-4 regulate Ca(2+) -dependent secretory lysosome exocytosis in mast cells.","date":"2008","source":"Journal of immunology (Baltimore, Md. : 1950)","url":"https://pubmed.ncbi.nlm.nih.gov/18354201","citation_count":47,"is_preprint":false},{"pmid":"25312756","id":"PMC_25312756","title":"Patients with Griscelli syndrome and normal pigmentation identify RAB27A mutations that selectively disrupt MUNC13-4 binding.","date":"2014","source":"The Journal of allergy and clinical immunology","url":"https://pubmed.ncbi.nlm.nih.gov/25312756","citation_count":42,"is_preprint":false},{"pmid":"28450451","id":"PMC_28450451","title":"A novel Munc13-4/S100A10/annexin A2 complex promotes Weibel-Palade body exocytosis in endothelial cells.","date":"2017","source":"Molecular biology of the cell","url":"https://pubmed.ncbi.nlm.nih.gov/28450451","citation_count":40,"is_preprint":false},{"pmid":"21746860","id":"PMC_21746860","title":"Increased survival and reduced neutrophil infiltration of the liver in Rab27a- but not Munc13-4-deficient mice in lipopolysaccharide-induced systemic inflammation.","date":"2011","source":"Infection and immunity","url":"https://pubmed.ncbi.nlm.nih.gov/21746860","citation_count":39,"is_preprint":false},{"pmid":"29665027","id":"PMC_29665027","title":"Genetic variant spectrum in 265 Chinese patients with hemophagocytic lymphohistiocytosis: Molecular analyses of PRF1, UNC13D, STX11, STXBP2, SH2D1A, and XIAP.","date":"2018","source":"Clinical genetics","url":"https://pubmed.ncbi.nlm.nih.gov/29665027","citation_count":39,"is_preprint":false},{"pmid":"21674762","id":"PMC_21674762","title":"Screening the PRF1, UNC13D, STX11, SH2D1A, XIAP, and ITK gene mutations in Chinese children with Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis.","date":"2011","source":"Pediatric blood & cancer","url":"https://pubmed.ncbi.nlm.nih.gov/21674762","citation_count":38,"is_preprint":false},{"pmid":"29409136","id":"PMC_29409136","title":"Brief Report: Novel UNC13D Intronic Variant Disrupting an NF-κB Enhancer in a Patient With Recurrent Macrophage Activation Syndrome and Systemic Juvenile Idiopathic Arthritis.","date":"2018","source":"Arthritis & rheumatology (Hoboken, N.J.)","url":"https://pubmed.ncbi.nlm.nih.gov/29409136","citation_count":36,"is_preprint":false},{"pmid":"23180437","id":"PMC_23180437","title":"Founder effects in two predominant intronic mutations of UNC13D, c.118-308C>T and c.754-1G>C underlie the unusual predominance of type 3 familial hemophagocytic lymphohistiocytosis (FHL3) in Korea.","date":"2012","source":"Annals of hematology","url":"https://pubmed.ncbi.nlm.nih.gov/23180437","citation_count":34,"is_preprint":false},{"pmid":"21653941","id":"PMC_21653941","title":"Rapid diagnosis of FHL3 by flow cytometric detection of intraplatelet Munc13-4 protein.","date":"2011","source":"Blood","url":"https://pubmed.ncbi.nlm.nih.gov/21653941","citation_count":34,"is_preprint":false},{"pmid":"26680738","id":"PMC_26680738","title":"Munc13-4 interacts with syntaxin 7 and regulates late endosomal maturation, endosomal signaling, and TLR9-initiated cellular responses.","date":"2015","source":"Molecular biology of the cell","url":"https://pubmed.ncbi.nlm.nih.gov/26680738","citation_count":33,"is_preprint":false},{"pmid":"24842371","id":"PMC_24842371","title":"Transcriptional regulation of Munc13-4 expression in cytotoxic lymphocytes is disrupted by an intronic mutation associated with a primary immunodeficiency.","date":"2014","source":"The Journal of experimental medicine","url":"https://pubmed.ncbi.nlm.nih.gov/24842371","citation_count":33,"is_preprint":false},{"pmid":"33867526","id":"PMC_33867526","title":"Germline variants in UNC13D and AP3B1 are enriched in COVID-19 patients experiencing severe cytokine storms.","date":"2021","source":"European journal of human genetics : EJHG","url":"https://pubmed.ncbi.nlm.nih.gov/33867526","citation_count":30,"is_preprint":false},{"pmid":"24470399","id":"PMC_24470399","title":"The 253-kb inversion and deep intronic mutations in UNC13D are present in North American patients with familial hemophagocytic lymphohistiocytosis 3.","date":"2014","source":"Pediatric blood & cancer","url":"https://pubmed.ncbi.nlm.nih.gov/24470399","citation_count":30,"is_preprint":false},{"pmid":"23115246","id":"PMC_23115246","title":"MUNC13-4 protein regulates the oxidative response and is essential for phagosomal maturation and bacterial killing in neutrophils.","date":"2012","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/23115246","citation_count":29,"is_preprint":false},{"pmid":"22271450","id":"PMC_22271450","title":"PIP2-dependent regulation of Munc13-4 endocytic recycling: impact on the cytolytic secretory pathway.","date":"2012","source":"Blood","url":"https://pubmed.ncbi.nlm.nih.gov/22271450","citation_count":27,"is_preprint":false},{"pmid":"31032638","id":"PMC_31032638","title":"Retroviral UNC13D Gene Transfer Restores Cytotoxic Activity of T Cells Derived from Familial Hemophagocytic Lymphohistiocytosis Type 3 Patients In Vitro.","date":"2019","source":"Human gene therapy","url":"https://pubmed.ncbi.nlm.nih.gov/31032638","citation_count":27,"is_preprint":false},{"pmid":"23840885","id":"PMC_23840885","title":"Variations of the UNC13D gene in patients with autoimmune lymphoproliferative syndrome.","date":"2013","source":"PloS one","url":"https://pubmed.ncbi.nlm.nih.gov/23840885","citation_count":26,"is_preprint":false},{"pmid":"26931073","id":"PMC_26931073","title":"Mast cell degranulation is negatively regulated by the Munc13-4-binding small-guanosine triphosphatase Rab37.","date":"2016","source":"Scientific reports","url":"https://pubmed.ncbi.nlm.nih.gov/26931073","citation_count":25,"is_preprint":false},{"pmid":"26637270","id":"PMC_26637270","title":"Role of Munc13-4 as a Ca2+-dependent tether during platelet secretion.","date":"2015","source":"The Biochemical journal","url":"https://pubmed.ncbi.nlm.nih.gov/26637270","citation_count":25,"is_preprint":false},{"pmid":"28100639","id":"PMC_28100639","title":"Munc13-4 functions as a Ca2+ sensor for homotypic secretory granule fusion to generate endosomal exocytic vacuoles.","date":"2017","source":"Molecular biology of the cell","url":"https://pubmed.ncbi.nlm.nih.gov/28100639","citation_count":24,"is_preprint":false},{"pmid":"29296930","id":"PMC_29296930","title":"Gene transfer into hematopoietic stem cells reduces HLH manifestations in a murine model of Munc13-4 deficiency.","date":"2017","source":"Blood advances","url":"https://pubmed.ncbi.nlm.nih.gov/29296930","citation_count":23,"is_preprint":false},{"pmid":"32679608","id":"PMC_32679608","title":"Clinical, immunological and genetic findings in patients with UNC13D deficiency (FHL3): A systematic review.","date":"2020","source":"Pediatric allergy and immunology : official publication of the European Society of Pediatric Allergy and Immunology","url":"https://pubmed.ncbi.nlm.nih.gov/32679608","citation_count":22,"is_preprint":false},{"pmid":"32253931","id":"PMC_32253931","title":"Lentiviral Gene Therapy for Familial Hemophagocytic Lymphohistiocytosis Type 3, Caused by UNC13D Genetic Defects.","date":"2020","source":"Human gene therapy","url":"https://pubmed.ncbi.nlm.nih.gov/32253931","citation_count":22,"is_preprint":false},{"pmid":"21370424","id":"PMC_21370424","title":"Hemophagocytic lymphohistiocytosis with MUNC13-4 gene mutation or reduced natural killer cell function prior to onset of childhood leukemia.","date":"2010","source":"Pediatric blood & cancer","url":"https://pubmed.ncbi.nlm.nih.gov/21370424","citation_count":21,"is_preprint":false},{"pmid":"16630545","id":"PMC_16630545","title":"Rab27a regulates epithelial sodium channel (ENaC) activity through synaptotagmin-like protein (SLP-5) and Munc13-4 effector mechanism.","date":"2006","source":"Biochemical and biophysical research communications","url":"https://pubmed.ncbi.nlm.nih.gov/16630545","citation_count":20,"is_preprint":false},{"pmid":"29674495","id":"PMC_29674495","title":"Platelet Munc13-4 regulates hemostasis, thrombosis and airway inflammation.","date":"2018","source":"Haematologica","url":"https://pubmed.ncbi.nlm.nih.gov/29674495","citation_count":18,"is_preprint":false},{"pmid":"24043286","id":"PMC_24043286","title":"Mutation of FAS, XIAP, and UNC13D genes in a patient with a complex lymphoproliferative phenotype.","date":"2013","source":"Pediatrics","url":"https://pubmed.ncbi.nlm.nih.gov/24043286","citation_count":18,"is_preprint":false},{"pmid":"36125406","id":"PMC_36125406","title":"UNC13D inhibits STING signaling by attenuating its oligomerization on the endoplasmic reticulum.","date":"2022","source":"EMBO reports","url":"https://pubmed.ncbi.nlm.nih.gov/36125406","citation_count":17,"is_preprint":false},{"pmid":"25980904","id":"PMC_25980904","title":"Synergistic defects of UNC13D and AP3B1 leading to adult hemophagocytic lymphohistiocytosis.","date":"2015","source":"International journal of hematology","url":"https://pubmed.ncbi.nlm.nih.gov/25980904","citation_count":17,"is_preprint":false},{"pmid":"21646258","id":"PMC_21646258","title":"Hemophagocytic lymphohistiocytosis with Munc13-4 mutation: a cause of recurrent fatal hydrops fetalis.","date":"2011","source":"Pediatrics","url":"https://pubmed.ncbi.nlm.nih.gov/21646258","citation_count":17,"is_preprint":false},{"pmid":"30892133","id":"PMC_30892133","title":"Cross-regulation of defective endolysosome trafficking and enhanced autophagy through TFEB in UNC13D deficiency.","date":"2019","source":"Autophagy","url":"https://pubmed.ncbi.nlm.nih.gov/30892133","citation_count":16,"is_preprint":false},{"pmid":"29884704","id":"PMC_29884704","title":"C2 Domains of Munc13-4 Are Crucial for Ca2+-Dependent Degranulation and Cytotoxicity in NK Cells.","date":"2018","source":"Journal of immunology (Baltimore, Md. : 1950)","url":"https://pubmed.ncbi.nlm.nih.gov/29884704","citation_count":16,"is_preprint":false},{"pmid":"28848550","id":"PMC_28848550","title":"Late-Onset Non-HLH Presentations of Growth Arrest, Inflammatory Arachnoiditis, and Severe Infectious Mononucleosis, in Siblings with Hypomorphic Defects in UNC13D.","date":"2017","source":"Frontiers in immunology","url":"https://pubmed.ncbi.nlm.nih.gov/28848550","citation_count":16,"is_preprint":false},{"pmid":"18432499","id":"PMC_18432499","title":"Fatal sibling cases of familial hemophagocytic lymphohistiocytosis (FHL) with MUNC13-4 mutations: case reports.","date":"2008","source":"Pediatric hematology and oncology","url":"https://pubmed.ncbi.nlm.nih.gov/18432499","citation_count":14,"is_preprint":false},{"pmid":"30758854","id":"PMC_30758854","title":"Haploinsufficiency of UNC13D increases the risk of lymphoma.","date":"2019","source":"Cancer","url":"https://pubmed.ncbi.nlm.nih.gov/30758854","citation_count":13,"is_preprint":false},{"pmid":"23709445","id":"PMC_23709445","title":"Novel mutations in the UNC13D gene carried by a Chinese neonate with hemophagocytic lymphohistiocytosis.","date":"2013","source":"Yonsei medical journal","url":"https://pubmed.ncbi.nlm.nih.gov/23709445","citation_count":13,"is_preprint":false},{"pmid":"39210440","id":"PMC_39210440","title":"Recycling machinery of integrin coupled with focal adhesion turnover via RAB11-UNC13D-FAK axis for migration of pancreatic cancer cells.","date":"2024","source":"Journal of translational medicine","url":"https://pubmed.ncbi.nlm.nih.gov/39210440","citation_count":10,"is_preprint":false},{"pmid":"34339548","id":"PMC_34339548","title":"Spectrum mutations of PRF1, UNC13D, STX11, and STXBP2 genes in Vietnamese patients with hemophagocytic lymphohistiocytosis.","date":"2021","source":"International journal of laboratory hematology","url":"https://pubmed.ncbi.nlm.nih.gov/34339548","citation_count":9,"is_preprint":false},{"pmid":"27408432","id":"PMC_27408432","title":"Familial Hemophagocytic Lymphohistiocytosis due to Mutation of UNC13D Gene.","date":"2015","source":"Indian journal of hematology & blood transfusion : an official journal of Indian Society of Hematology and Blood Transfusion","url":"https://pubmed.ncbi.nlm.nih.gov/27408432","citation_count":9,"is_preprint":false},{"pmid":"22482013","id":"PMC_22482013","title":"Munc13-4*rab27 complex tethers secretory lysosomes at the plasma membrane.","date":"2012","source":"Communicative & integrative biology","url":"https://pubmed.ncbi.nlm.nih.gov/22482013","citation_count":9,"is_preprint":false},{"pmid":"16416131","id":"PMC_16416131","title":"Familial hemophagocytic lymphohistiocytosis with the MUNC13-4 mutation: a case report.","date":"2006","source":"European journal of pediatrics","url":"https://pubmed.ncbi.nlm.nih.gov/16416131","citation_count":9,"is_preprint":false},{"pmid":"32582217","id":"PMC_32582217","title":"Alternative UNC13D Promoter Encodes a Functional Munc13-4 Isoform Predominantly Expressed in Lymphocytes and Platelets.","date":"2020","source":"Frontiers in immunology","url":"https://pubmed.ncbi.nlm.nih.gov/32582217","citation_count":8,"is_preprint":false},{"pmid":"21755595","id":"PMC_21755595","title":"A novel Dutch mutation in UNC13D reveals an essential role of the C2B domain in munc13-4 function.","date":"2011","source":"Pediatric blood & cancer","url":"https://pubmed.ncbi.nlm.nih.gov/21755595","citation_count":8,"is_preprint":false},{"pmid":"31897916","id":"PMC_31897916","title":"TNF Production in Activated RBL-2H3 Cells Requires Munc13-4.","date":"2020","source":"Inflammation","url":"https://pubmed.ncbi.nlm.nih.gov/31897916","citation_count":8,"is_preprint":false},{"pmid":"24825797","id":"PMC_24825797","title":"Novel and atypical splicing mutation in a compound heterozygous UNC13D defect presenting in Familial Hemophagocytic Lymphohistiocytosis triggered by EBV infection.","date":"2014","source":"Clinical immunology (Orlando, Fla.)","url":"https://pubmed.ncbi.nlm.nih.gov/24825797","citation_count":8,"is_preprint":false},{"pmid":"29596912","id":"PMC_29596912","title":"Characterization of a large UNC13D gene duplication in a patient with familial hemophagocytic lymphohistiocytosis type 3.","date":"2018","source":"Clinical immunology (Orlando, Fla.)","url":"https://pubmed.ncbi.nlm.nih.gov/29596912","citation_count":8,"is_preprint":false},{"pmid":"29864493","id":"PMC_29864493","title":"Synergistic defects of novo FAS and homozygous UNC13D leading to autoimmune lymphoproliferative syndrome-like disease: A 10-year-old Chinese boy case report.","date":"2018","source":"Gene","url":"https://pubmed.ncbi.nlm.nih.gov/29864493","citation_count":8,"is_preprint":false},{"pmid":"39469717","id":"PMC_39469717","title":"Functional role of UNC13D in immune diseases and its therapeutic applications.","date":"2024","source":"Frontiers in immunology","url":"https://pubmed.ncbi.nlm.nih.gov/39469717","citation_count":7,"is_preprint":false},{"pmid":"29615494","id":"PMC_29615494","title":"Small molecules that inhibit the late stage of Munc13-4-dependent secretory granule exocytosis in mast cells.","date":"2018","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/29615494","citation_count":7,"is_preprint":false},{"pmid":"29157204","id":"PMC_29157204","title":"Characterization of a novel splicing mutation in UNC13D gene through amplicon sequencing: a case report on HLH.","date":"2017","source":"BMC medical genetics","url":"https://pubmed.ncbi.nlm.nih.gov/29157204","citation_count":6,"is_preprint":false},{"pmid":"25252047","id":"PMC_25252047","title":"Munc13-4 deficiency with CD5 downregulation on activated CD8+ T cells.","date":"2014","source":"Pediatrics international : official journal of the Japan Pediatric Society","url":"https://pubmed.ncbi.nlm.nih.gov/25252047","citation_count":6,"is_preprint":false},{"pmid":"36401200","id":"PMC_36401200","title":"Familial Hemophagocytic Lymphohistiocytosis secondary to UNC13D mutation: a report of two cases.","date":"2022","source":"BMC pediatrics","url":"https://pubmed.ncbi.nlm.nih.gov/36401200","citation_count":5,"is_preprint":false},{"pmid":"18413249","id":"PMC_18413249","title":"Methods for analysis of rab27a/Munc13-4 in secretory lysosome release in hematopoietic cells.","date":"2008","source":"Methods in enzymology","url":"https://pubmed.ncbi.nlm.nih.gov/18413249","citation_count":5,"is_preprint":false},{"pmid":"41083534","id":"PMC_41083534","title":"Munc13-4 mediates tumor immune evasion by regulating the sorting and secretion of PD-L1 via exosomes.","date":"2025","source":"Nature communications","url":"https://pubmed.ncbi.nlm.nih.gov/41083534","citation_count":4,"is_preprint":false},{"pmid":"29767240","id":"PMC_29767240","title":"Munc13‑4 mediates human neutrophil elastase‑induced airway mucin5AC hypersecretion by interacting with syntaxin2.","date":"2018","source":"Molecular medicine reports","url":"https://pubmed.ncbi.nlm.nih.gov/29767240","citation_count":4,"is_preprint":false},{"pmid":"40943599","id":"PMC_40943599","title":"UNC13D c.2588G>A Nucleotide Variant Impairs NK-Cell Cytotoxicity in Adult-Onset EBV-Associated Hemophagocytic Lymphohistiocytosis: A Pedigree Study.","date":"2025","source":"International journal of molecular sciences","url":"https://pubmed.ncbi.nlm.nih.gov/40943599","citation_count":4,"is_preprint":false},{"pmid":"29783935","id":"PMC_29783935","title":"Identification of a novel nonsense mutation in the UNC13D gene from a patient with hemophagocytic lymphohistiocytosis: a case report.","date":"2018","source":"BMC medical genetics","url":"https://pubmed.ncbi.nlm.nih.gov/29783935","citation_count":4,"is_preprint":false},{"pmid":"30710289","id":"PMC_30710289","title":"Analysis of Ca2+-Dependent Weibel-Palade Body Tethering by Live Cell TIRF Microscopy: Involvement of a Munc13-4/S100A10/Annexin A2 Complex.","date":"2019","source":"Methods in molecular biology (Clifton, N.J.)","url":"https://pubmed.ncbi.nlm.nih.gov/30710289","citation_count":4,"is_preprint":false},{"pmid":"23774160","id":"PMC_23774160","title":"Defective UNC13D gene-associated familial hemophagocytic lymphohistiocytosis triggered by visceral leishmaniasis: a diagnostic challenge.","date":"2014","source":"Journal of pediatric hematology/oncology","url":"https://pubmed.ncbi.nlm.nih.gov/23774160","citation_count":4,"is_preprint":false},{"pmid":"26377049","id":"PMC_26377049","title":"A Hemophagocytic Lymphohistiocytosis Case with Newly Defined UNC13D (c.175G>C; p.Ala59Pro) Mutation and a Rare Complication.","date":"2015","source":"Turkish journal of haematology : official journal of Turkish Society of Haematology","url":"https://pubmed.ncbi.nlm.nih.gov/26377049","citation_count":3,"is_preprint":false},{"pmid":"29415165","id":"PMC_29415165","title":"Neonatal Cytomegalovirus Palatal Ulceration and Bocavirus Pneumonitis Associated With a Defect of Lymphocyte Cytotoxicity Caused by Mutations in UNC13D.","date":"2019","source":"Journal of the Pediatric Infectious Diseases Society","url":"https://pubmed.ncbi.nlm.nih.gov/29415165","citation_count":3,"is_preprint":false},{"pmid":"38183241","id":"PMC_38183241","title":"Relapsed/Refractory Peripheral T-Cell Lymphoma-Associated Hemophagocytic Lymphohistiocytosis With UNC13D and CD27 Germline Mutations.","date":"2024","source":"Cell transplantation","url":"https://pubmed.ncbi.nlm.nih.gov/38183241","citation_count":2,"is_preprint":false},{"pmid":"40021841","id":"PMC_40021841","title":"Investigation of a pathogenic inversion in UNC13D and comprehensive analysis of chromosomal inversions across diverse datasets.","date":"2025","source":"European journal of human genetics : EJHG","url":"https://pubmed.ncbi.nlm.nih.gov/40021841","citation_count":2,"is_preprint":false},{"pmid":"32245292","id":"PMC_32245292","title":"Clinical and Genetic Analysis of Nine Suspected Familial Haemophagocytic Lymphohistiocytosis Patients for MUNC13-4 Deficiency and Introducing Four Novel Mutations in UNC13D.","date":"2019","source":"Iranian journal of allergy, asthma, and immunology","url":"https://pubmed.ncbi.nlm.nih.gov/32245292","citation_count":1,"is_preprint":false},{"pmid":"38212754","id":"PMC_38212754","title":"Detection of a novel gross deletion in the UNC13D gene ends the diagnostic odyssey for a family with familial hemophagocytic lymphohistiocytosis 3.","date":"2024","source":"BMC pediatrics","url":"https://pubmed.ncbi.nlm.nih.gov/38212754","citation_count":1,"is_preprint":false},{"pmid":"40901478","id":"PMC_40901478","title":"Clinical and genetic features of UNC13D deficiency with hypogammaglobulinemia.","date":"2025","source":"Frontiers in immunology","url":"https://pubmed.ncbi.nlm.nih.gov/40901478","citation_count":0,"is_preprint":false},{"pmid":"42032368","id":"PMC_42032368","title":"UNC13D in Familial Hemophagocytic Lymphohistiocytosis and Beyond: Functional Mechanisms, Genetic Variants, Multisystem Disease Spectrum and Clinical Implications.","date":"2026","source":"Scandinavian journal of immunology","url":"https://pubmed.ncbi.nlm.nih.gov/42032368","citation_count":0,"is_preprint":false},{"pmid":"41942734","id":"PMC_41942734","title":"Munc13-4-STX7 inhibitors impair endosomal TLR activation and systemic inflammation.","date":"2026","source":"Nature chemical biology","url":"https://pubmed.ncbi.nlm.nih.gov/41942734","citation_count":0,"is_preprint":false},{"pmid":"41028446","id":"PMC_41028446","title":"Hemophagocytic lymphohistiocytosis caused by dual mutations in UNC13D and STX11 induced by HHV-7: a case report and review of the literature.","date":"2025","source":"Annals of hematology","url":"https://pubmed.ncbi.nlm.nih.gov/41028446","citation_count":0,"is_preprint":false},{"pmid":"41394838","id":"PMC_41394838","title":"Human herpesvirus 6B infection in an adult with hemophagocytic lymphohistiocytosis carrying an UNC13D mutation: a case report and literature review.","date":"2025","source":"Frontiers in immunology","url":"https://pubmed.ncbi.nlm.nih.gov/41394838","citation_count":0,"is_preprint":false},{"pmid":"39858121","id":"PMC_39858121","title":"Molecular Characterization and Expression of unc-13d in the Sex Reversal of Monopterus albus.","date":"2025","source":"Animals : an open access journal from MDPI","url":"https://pubmed.ncbi.nlm.nih.gov/39858121","citation_count":0,"is_preprint":false},{"pmid":"39574843","id":"PMC_39574843","title":"Investigation of a Pathogenic Inversion in UNC13D and Comprehensive Analysis of Chromosomal Inversions Across Diverse Datasets.","date":"2024","source":"medRxiv : the preprint server for health sciences","url":"https://pubmed.ncbi.nlm.nih.gov/39574843","citation_count":0,"is_preprint":false},{"pmid":"40951263","id":"PMC_40951263","title":"Molecular requirements for mammalian crinophagy highlight a key role for Ca2+-dependent Munc13-4.","date":"2025","source":"Research square","url":"https://pubmed.ncbi.nlm.nih.gov/40951263","citation_count":0,"is_preprint":false},{"pmid":"41781714","id":"PMC_41781714","title":"Two Cases of CLIPPERS-like Syndrome Sharing a Hypomorphic UNC13D Variant.","date":"2026","source":"Journal of clinical immunology","url":"https://pubmed.ncbi.nlm.nih.gov/41781714","citation_count":0,"is_preprint":false},{"pmid":"23815924","id":"PMC_23815924","title":"[Type III familial hemophagocytic lymphohistiocytosis susceptibility gene UNC13D involves in homologous recombination repair].","date":"2013","source":"Zhongguo shi yan xue ye xue za zhi","url":"https://pubmed.ncbi.nlm.nih.gov/23815924","citation_count":0,"is_preprint":false},{"pmid":"41784029","id":"PMC_41784029","title":"Genetic and clinical characteristics of 54 pediatric lymphoma patients with variant mutation sites of UNC13D.","date":"2026","source":"Haematologica","url":"https://pubmed.ncbi.nlm.nih.gov/41784029","citation_count":0,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":51223,"output_tokens":10257,"usd":0.153762,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":20449,"output_tokens":6981,"usd":0.138385,"stage2_stop_reason":"end_turn"},"total_usd":0.292147,"stage1_batch_id":"msgbatch_017qqVz33Ga63SCDwzb35XPb","stage2_batch_id":"msgbatch_01Scr2Ei9x4HJMiRGxwrmvLK","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2003,\n      \"finding\": \"Munc13-4 (hMunc13-4) is essential for the priming step of cytolytic granule secretion preceding vesicle membrane fusion in cytotoxic T lymphocytes. Mutations in UNC13D cause FHL3. Deficiency results in defective cytolytic granule exocytosis despite normal polarization and docking of granules to the plasma membrane. Expressed tagged hMunc13-4 localizes with cytotoxic granules at the immunological synapse.\",\n      \"method\": \"Patient mutation analysis, subcellular localization of tagged protein (fluorescence microscopy), functional exocytosis assay in patient cells\",\n      \"journal\": \"Cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — first identification paper with mutation analysis, localization experiments, and functional exocytosis assays; independently replicated across multiple subsequent studies\",\n      \"pmids\": [\"14622600\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2003,\n      \"finding\": \"Munc13-4 is a GTP-Rab27A- and Rab27B-binding protein in platelets. Recombinant Munc13-4 directly binds GTP-Rab27A and Rab27B in vitro but not other GTPases, and enhances dense core granule secretion in a permeabilized platelet assay. Inhibition of secretion by unprenylated Rab27A was rescued by addition of Munc13-4, demonstrating that Munc13-4 mediates the effector function of GTP-Rab27.\",\n      \"method\": \"Affinity purification, in vitro binding assay (recombinant proteins), permeabilized platelet secretion assay with rescue experiment\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — in vitro reconstitution with recombinant proteins plus functional rescue assay; replicated in multiple subsequent studies\",\n      \"pmids\": [\"14699162\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2006,\n      \"finding\": \"Missense mutation Leu403Pro in hMunc13-4 prevents formation of a stable hMunc13-4/Rab27a complex in vitro, demonstrating that specific residues in Munc13-4 are required for Rab27a interaction.\",\n      \"method\": \"Mammalian two-hybrid system (functional protein interaction assay in vitro)\",\n      \"journal\": \"Human mutation\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — mammalian two-hybrid, single lab, functionally informative missense mutant\",\n      \"pmids\": [\"16278825\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2008,\n      \"finding\": \"In human neutrophils, Munc13-4 is mainly cytosolic at rest and is rapidly recruited to membranes following fMLF stimulation in a Ca2+-dependent manner. A pool of Munc13-4 associated with secondary and tertiary granules is relocalized to the plasma membrane after fMLF stimulation. C2 domains of Munc13-4 bind phospholipid vesicles in a Ca2+-independent manner. Knockdown of Munc13-4 decreases tertiary granule exocytosis; overexpression enhances MMP-9 secretion.\",\n      \"method\": \"Cell fractionation, immunofluorescence, siRNA knockdown, phospholipid binding assay, secretion ELISA\",\n      \"journal\": \"Journal of immunology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple orthogonal methods (fractionation, localization, KD, OE, binding assay) in single lab\",\n      \"pmids\": [\"18453599\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2008,\n      \"finding\": \"Doc2alpha co-localizes with Munc13-4 on secretory lysosomes in mast cells and interacts with Munc13-4 through two regions: the N-terminus (containing the Munc13-1-interacting domain) and the C-terminus (C2B domain). This Doc2alpha–Munc13-4 complex regulates Ca2+-dependent secretory lysosome exocytosis; mutations in either binding region or Doc2alpha knockdown impair exocytosis, rescued by Munc13-4 coexpression.\",\n      \"method\": \"Co-immunoprecipitation, co-localization (confocal microscopy), dominant-negative mutant expression, siRNA knockdown, rescue experiment, knockout mouse BMMC assay\",\n      \"journal\": \"Journal of immunology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal co-IP, co-localization, KO mouse, mutant rescue; multiple orthogonal methods\",\n      \"pmids\": [\"18354201\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2008,\n      \"finding\": \"Munc13-4 regulates exocytosis of multiple neutrophil granule subsets (gelatinase/tertiary granules). Munc13-4 localizes at secretory organelles in neutrophils. Using Munc13-4-deficient (Jinx) mouse neutrophils, Munc13-4 was shown to be required for exocytosis of various secretory organelles, though CD11b mobilization was not affected.\",\n      \"method\": \"siRNA, total internal reflection fluorescence microscopy, Unc13d(Jinx) knockout mouse neutrophils, granule secretion assays\",\n      \"journal\": \"Traffic\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — KO mouse model plus TIRF microscopy and multiple secretion assays; replicated across labs\",\n      \"pmids\": [\"18939952\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"Munc13-4 and Rab27a are recruited to lytic granules in a stimulus-dependent manner in NK cells, but different receptor signals preferentially recruit Rab27a vs. Munc13-4: NKG2D and LFA-1 engagement induced Rab27a but not Munc13-4 colocalization with perforin, while CD16 (ADCC receptor) engagement induced Munc13-4 but not Rab27a colocalization. Colocalization of Munc13-4 with perforin was Rab27a-dependent.\",\n      \"method\": \"Immunofluorescence confocal microscopy of primary NK cells, receptor-specific stimulation, patient cells (Rab27a- and Munc13-4-deficient)\",\n      \"journal\": \"Blood\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — live-cell and fixed co-localization in primary patient and control cells with defined receptor stimulation conditions; single lab\",\n      \"pmids\": [\"19704116\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"Munc13-4 is a limiting factor in platelet secretion and hemostasis. Unc13d(Jinx) platelets lack Munc13-4 and show complete ablation of dense granule release and severe impairment of alpha-granule and lysosome secretion, reduced aggregation, and prolonged tail-bleeding times. The secretion defect is not due to altered SNARE expression or granule biogenesis. Recombinant Munc13-4 added to permeabilized Unc13d(Jinx) platelets rescues secretion. Munc13-4 levels directly correlate with extent of granule release.\",\n      \"method\": \"Unc13d(Jinx) mouse platelets, granule secretion assays, rescue with recombinant protein in permeabilized cells, tail bleeding time, aggregometry\",\n      \"journal\": \"Blood\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — reconstitution with recombinant protein in permeabilized cells, KO mouse model, multiple granule types assessed, dose-response correlation; rigorous multi-method study\",\n      \"pmids\": [\"20435885\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"The Munc13-4–Rab27a complex is specifically required for tethering secretory lysosomes at the plasma membrane during degranulation. A non-canonical Rab27a-binding motif in the N-terminus of Munc13-4 was identified; point mutants impairing Rab27a binding fail to rescue degranulation in FHL3 patient CTLs and mast cells silenced for Munc13-4. TIRF microscopy revealed that the complex corrals motile secretory lysosomes beneath the plasma membrane; loss of Rab27a binding abolishes this tethering/docking function while not affecting secretory lysosome maturation.\",\n      \"method\": \"Mutagenesis of Rab27a-binding motif, complementation assay in FHL3 patient CTLs, mast cell siRNA knockdown, TIRF microscopy\",\n      \"journal\": \"Blood\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — mutagenesis combined with TIRF imaging, patient cell complementation, and mast cell rescue; multiple orthogonal methods in single rigorous study\",\n      \"pmids\": [\"21693760\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"Munc13-4 binds Ca2+ through its C2A and C2B domains and reconstitutes Ca2+-dependent granule exocytosis in permeable cells (platelets, mast, and neuroendocrine cells) dependent on putative Ca2+-binding residues in both C2A and C2B. Munc13-4 exhibits Ca2+-stimulated SNARE interactions dependent on C2A, and Ca2+-dependent membrane binding dependent on C2B. Munc13-4 stimulates SNARE-dependent liposome fusion in a Ca2+- and C2 domain-dependent manner. Munc13-4 is the first priming factor shown to promote Ca2+-dependent SNARE complex formation and SNARE-mediated liposome fusion.\",\n      \"method\": \"In vitro Ca2+ binding assay, permeable cell exocytosis assay with mutagenesis of Ca2+-binding residues, SNARE binding assay, liposome fusion reconstitution assay\",\n      \"journal\": \"The Journal of cell biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — in vitro reconstitution of liposome fusion, Ca2+ binding measurements, mutagenesis, permeable cell assay; multiple orthogonal methods in one rigorous study\",\n      \"pmids\": [\"22508512\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"MUNC13-4 is essential for phagosomal maturation and bacterial killing in neutrophils. MUNC13-4-deficient (KO) mouse neutrophils show impaired p22phox-expressing granule trafficking to the plasma membrane, defective extracellular and intracellular ROS production, impaired delivery of azurophilic granules and multivesicular bodies to the phagosome, and markedly impaired intracellular killing of P. aeruginosa. This phagosomal maturation function is RAB27A-independent.\",\n      \"method\": \"Munc13-4 KO mouse neutrophils, vesicle trafficking assays, ROS measurement, bacterial killing assay, comparison with Rab27a KO\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — KO mouse model, multiple phenotypic readouts (ROS, phagosome maturation, bacterial killing), RAB27A KO comparison establishing independence\",\n      \"pmids\": [\"23115246\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"PIP2 regulates Munc13-4 compartmentalization in NK cells. Granule secretion triggering induces transient Munc13-4 raft recruitment followed by AP-2/clathrin-dependent internalization. PIP5K-gamma silencing impairs granule secretion with increased raft-associated Munc13-4 due to defective AP-2 recruitment, impairing Munc13-4 reinternalization. This Munc13-4 endocytic recycling is required to maintain an intracellular pool necessary for serial NK cell killing.\",\n      \"method\": \"siRNA silencing of PIP5K-gamma, biochemical fractionation (membrane raft isolation), co-immunoprecipitation, serial killing assay in primary NK cells\",\n      \"journal\": \"Blood\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — siRNA, fractionation, functional killing assay; single lab, multiple methods\",\n      \"pmids\": [\"22271450\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"In mast cells, Rab27b (not Rab27a) acts as a positive regulator of degranulation through its effector Munc13-4. Munc13-4-deficient (Jinx) BMMCs phenocopy Rab27b KO and Rab27a/b double-KO secretory impairment, consistent with Munc13-4 acting downstream of Rab27b in granule exocytosis.\",\n      \"method\": \"Knockout mouse BMMCs (Rab27a ashen, Rab27b KO, Munc13-4 Jinx, double KO), degranulation assays, pharmacological actin disruption\",\n      \"journal\": \"The FEBS journal\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple KO mouse models with genetic epistasis; single study but rigorous genetic dissection\",\n      \"pmids\": [\"23281710\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"Transcription of UNC13D in cytotoxic lymphocytes is regulated by an intronic enhancer/alternative promoter in intron 1. The FHL3-associated mutation c.118-308C>T disrupts binding of the ETS family transcription factor ELF1 to this conserved intronic sequence, impairing STAT4 and BRG1 (chromatin remodeling complex) recruitment, reducing active histone modifications and diminishing Munc13-4 expression. TCR engagement facilitates STAT4-dependent Munc13-4 expression in naive CD8+ T cells.\",\n      \"method\": \"Electrophoretic mobility shift assay, chromatin immunoprecipitation, reporter assay, quantitative PCR in patient PBMCs, histone modification analysis\",\n      \"journal\": \"The Journal of experimental medicine\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — ChIP, EMSA, reporter assay, patient cells; multiple orthogonal methods establishing transcriptional mechanism\",\n      \"pmids\": [\"24842371\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"Rab27a mutations at residues R141, Y159, and S163 selectively disrupt Rab27a interaction with Munc13-4 without impairing Rab27a–melanophilin interaction, identifying a critical binding site for Munc13-4 on Rab27a.\",\n      \"method\": \"Patient mutation analysis, functional interaction assays in patient cells, protein interaction studies\",\n      \"journal\": \"The Journal of allergy and clinical immunology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — patient-derived mutations with selective binding disruption established by functional assays; single study\",\n      \"pmids\": [\"25312756\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"Munc13-4 binds Rab11a (but not dominant-negative Rab11a) and regulates trafficking and docking of Rab11-positive vesicles at the plasma membrane in neutrophils. A Ca2+-binding-deficient Munc13-4 mutant significantly impairs Rab11 trafficking. Munc13-4-deficient neutrophils show normal endocytosis but impaired Rab11-vesicle trafficking, up-regulation, and retention at the plasma membrane, correlating with deficient NADPH oxidase activation.\",\n      \"method\": \"TR-FRET binding assay, co-immunoprecipitation, super-resolution microscopy, vesicular dynamics analysis, Munc13-4 KO mouse neutrophils, Ca2+-binding mutant expression\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — novel TR-FRET assay plus co-IP, super-resolution microscopy, KO neutrophils, mutagenesis; multiple orthogonal methods\",\n      \"pmids\": [\"26637356\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"Munc13-4 acts as a Ca2+-dependent tether during platelet secretion. Ca2+-dependent enhancement of SNARE-dependent proteoliposome fusion requires both C2 domains of Munc13-4 and the Ca2+-coordinating aspartate residues of C2B specifically. Munc13-4 clusters PS-containing liposomes in response to Ca2+. Analytical ultracentrifugation shows Munc13-4 is a monomeric prolate ellipsoid with dimensions compatible with bridging two fusing membranes. Dense granules are highly mobile in Munc13-4-null platelets at rest and during stimulation with no stimulation-dependent release, indicating Munc13-4 plays a vesicle-stabilizing/tethering role.\",\n      \"method\": \"In vitro SNARE-dependent proteoliposome fusion assay, mutagenesis of C2 domain Ca2+-liganding residues, liposome clustering assay, analytical ultracentrifugation, live-cell mepacrine dense granule imaging in Unc13d(Jinx) platelets\",\n      \"journal\": \"The Biochemical journal\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — in vitro reconstitution with mutagenesis, liposome assays, structural analysis (AUC), and live-cell imaging in KO platelets; multiple rigorous methods\",\n      \"pmids\": [\"26637270\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"Munc13-4 interacts with syntaxin 7 (STX7) and VAMP8, with Ca2+ significantly increasing Munc13-4–STX7 binding. A STX7-binding-deficient Munc13-4 mutant fails to rescue late endosomal maturation defects in Munc13-4-deficient cells. Munc13-4 regulates late endosomal maturation: its deficiency causes enlarged late endosomes and decreased degradative capacity. Munc13-4-KO neutrophils show impaired TLR9-dependent signaling and CD11b up-regulation.\",\n      \"method\": \"Co-immunoprecipitation, high-resolution and live-cell microscopy, rescue assay with STX7-binding-deficient mutant, late endosome size/function quantification, TLR9 signaling assay in KO neutrophils\",\n      \"journal\": \"Molecular biology of the cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — co-IP with Ca2+ dependence, mutant rescue, KO cells, multiple functional readouts; rigorous multi-method study\",\n      \"pmids\": [\"26680738\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"Rab37, a small GTPase present on mast cell secretory granules, binds Munc13-4 in a GTP-independent manner and forms a Rab27–Munc13-4–Rab37 ternary complex. Rab37 negatively regulates mast cell degranulation; Rab37 knockdown causes hypersecretion that is suppressed by co-knockdown of Rab27a/b or Munc13-4, indicating Rab37 acts through the Rab27–Munc13-4 system.\",\n      \"method\": \"co-immunoprecipitation, siRNA knockdown, dominant-active mutant overexpression, degranulation assay in RBL-2H3 cells\",\n      \"journal\": \"Scientific reports\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — co-IP, genetic epistasis via double knockdown, functional assay; single lab\",\n      \"pmids\": [\"26931073\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"Munc13-4 functions as a tethering/priming factor and Ca2+ sensor for both heterotypic secretory granule (SG)–plasma membrane and homotypic SG–SG fusion in mast cells. Ca2+ stimulation generates large Munc13-4+/Rab7+/Rab11+ endosomal vacuoles through homotypic SG fusion, dependent on Ca2+ binding to Munc13-4. Munc13-4 promotes Ca2+-stimulated fusion of VAMP8-containing liposomes with both exocytic and endosomal Q-SNARE liposomes, and directly interacts with late endosomal SNARE complexes. Vacuoles are exocytic and mediate secretion.\",\n      \"method\": \"Ca2+ stimulation live-cell imaging, TIRF microscopy, liposome fusion assay with VAMP8-containing and Q-SNARE liposomes, Ca2+-binding mutants, SNARE co-precipitation\",\n      \"journal\": \"Molecular biology of the cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — in vitro liposome fusion reconstitution, Ca2+ binding mutants, TIRF imaging, SNARE interaction; multiple orthogonal methods in one study\",\n      \"pmids\": [\"28100639\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"Munc13-4 is a Weibel-Palade body (WPB) tethering factor in endothelial cells. Munc13-4 is present on WPBs and its secretagogue-evoked recruitment to WPBs is increased at sites of WPB–plasma membrane contact. Munc13-4 promotes histamine-evoked WPB exocytosis. The S100A10 subunit of the annexin A2–S100A10 complex is a novel Munc13-4 interactor that participates in recruiting Munc13-4 to WPB fusion sites.\",\n      \"method\": \"Fluorescence microscopy (TIRF), co-immunoprecipitation, siRNA knockdown, von Willebrand factor secretion assay in endothelial cells\",\n      \"journal\": \"Molecular biology of the cell\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — co-IP for new interaction, TIRF imaging, functional knockdown; single lab, multiple methods\",\n      \"pmids\": [\"28450451\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"Munc13-4 regulates a Ca2+-stimulated exosome release pathway in cancer cells. Munc13-4 knockdown eliminates Ca2+-triggered CD63+/CD9+/ALIX+ exosome release; Ca2+-binding-deficient Munc13-4 mutants fail to restore this release. Munc13-4 depletion reduces the size of CD63+ multivesicular bodies (MVBs) in breast carcinoma cells. Munc13-4 uses a Rab11-dependent trafficking pathway to generate MVBs competent for exosome release. Munc13-4 depletion reduces MT1-MMP trafficking to MVBs and extracellular matrix degradation.\",\n      \"method\": \"siRNA knockdown, Ca2+-binding-deficient mutant rescue, CD63-pHluorin live imaging, MVB size quantification, MT1-MMP trafficking assay, ECM degradation assay\",\n      \"journal\": \"The Journal of cell biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — live imaging of exosome release, mutant rescue, MVB morphology, multiple functional readouts; multiple orthogonal methods in one rigorous study\",\n      \"pmids\": [\"29930202\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"Both C2 domains of Munc13-4 are critical Ca2+ sensors for NK cell degranulation and cytotoxicity. Point mutations in aspartate residues in either C2A or C2B diminish exocytosis, alter Ca2+ sensitivity of fusion pore opening, and impair NK cell cytotoxicity against malignant cells. TIRF microscopy showed these mutations alter Ca2+ dependence and frequency of single-granule fusion events.\",\n      \"method\": \"Site-directed mutagenesis of C2A/C2B Ca2+-coordinating aspartates, expression in primary mouse NK cells and RBL mast cells, TIRF single-granule imaging, cytotoxicity assay\",\n      \"journal\": \"Journal of immunology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — mutagenesis of active-site residues with single-granule TIRF imaging and cytotoxicity assays in primary NK cells; multiple orthogonal methods\",\n      \"pmids\": [\"29884704\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"Platelet-specific deletion of Munc13-4 ablates dense granule release and indirectly impairs alpha-granule exocytosis (Munc13-2 has no exocytic role in platelets even in absence of Munc13-4). Munc13-4 acts as a rate-limiting factor in thrombus formation in vitro and in vivo. Munc13-4 expression in platelets dose-dependently regulates venous bleeding time and arterial thrombosis. Platelet-specific Munc13-4 KO reduces airway hyper-responsiveness and eosinophilic inflammation in allergic model.\",\n      \"method\": \"Conditional Munc13-4 KO mice (platelet-specific), granule secretion assays, flow chamber thrombosis assay, in vivo bleeding and thrombosis models, airway inflammation model\",\n      \"journal\": \"Haematologica\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — conditional KO mouse model with multiple in vitro and in vivo functional readouts; rigorous genetic study\",\n      \"pmids\": [\"29674495\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"An intronic UNC13D variant (c.117+143A>G) disrupts NF-κB binding to a functional transcriptional enhancer in intron 1, reducing UNC13D transcript levels in patient PBMCs and impairing NK cell degranulation. This was demonstrated by EMSA showing disrupted NF-κB binding and in vitro transcriptional enhancer assay showing reduced activity.\",\n      \"method\": \"EMSA, in vitro transcriptional enhancer assay, qPCR of patient PBMCs, NK cell degranulation assay, partial UNC13D knockdown\",\n      \"journal\": \"Arthritis & rheumatology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — EMSA and reporter assay define molecular mechanism; patient-derived cells confirm functional consequence; single lab\",\n      \"pmids\": [\"29409136\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"UNC13D-deficient cells show impaired endosomal trafficking, defective endocytic flux, and increased autophagic flux. The defective endosomal phenotype is rescued by UNC13D but not by its STX7-binding-deficient mutant. The increased autophagy in UNC13D-deficient cells is driven at least in part by TFEB-mediated upregulation of autophagic and lysosomal genes including Atg9b; TFEB knockdown reduces Atg9b and autophagy. UNC13D upregulation corrects endolysosomal trafficking and reduces autophagosome accumulation in a cystinosis cell model.\",\n      \"method\": \"KO cells, rescue with WT vs. STX7-binding mutant, autophagy flux assays, TFEB knockdown, biochemical and microscopy methods, cystinosis cell model\",\n      \"journal\": \"Autophagy\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — KO cells with mutant rescue, TFEB epistasis, multiple readouts; single lab\",\n      \"pmids\": [\"30892133\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"UNC13D encodes two isoforms with distinct N-termini driven by an alternative promoter/TSS in intron 1. The alternative (lymphocyte/platelet-predominant) isoform has a unique N-terminus but does not differ from the conventional isoform in Munc13-4 localization, trafficking to the immunological synapse, or ability to restore exocytosis in FHL3 patient T cells. Both isoforms equivalently rescue degranulation.\",\n      \"method\": \"Isoform-specific antibodies, subcellular localization (imaging), complementation/rescue assay in FHL3 patient T cells, ectopic expression\",\n      \"journal\": \"Frontiers in immunology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — isoform-specific antibodies with patient cell complementation; single lab, multiple methods\",\n      \"pmids\": [\"32582217\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"UNC13D co-localizes with STING on the endoplasmic reticulum and inhibits STING oligomerization. Knockdown or knockout of UNC13D promotes IFN-β production in response to DNA viruses (but not RNA viruses) and increases basal proinflammatory cytokine levels, effects abolished by a STING inhibitor. The domains on both UNC13D and STING mediating their interaction were mapped.\",\n      \"method\": \"Co-localization (fluorescence microscopy), co-immunoprecipitation/interaction mapping, UNC13D knockdown and knockout, IFN-β reporter/ELISA, STING inhibitor rescue\",\n      \"journal\": \"EMBO reports\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — co-IP with domain mapping, KO cells, functional innate immune signaling assays; single lab, multiple methods\",\n      \"pmids\": [\"36125406\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"UNC13D regulates pancreatic cancer cell migration by coupling exocytosis of recycling endosomes with focal adhesion turnover through the RAB11–UNC13D–FAK axis. UNC13D directly interacts with the FERM domain of FAK and regulates FAK phosphorylation in a calcium-dependent manner. Immunoprecipitation confirmed the RAB11–UNC13D–FAK complex in endosomes during integrin recycling.\",\n      \"method\": \"Co-immunoprecipitation, immunocytochemistry, migration assays, FAK phosphorylation assay, domain interaction mapping (FERM domain)\",\n      \"journal\": \"Journal of translational medicine\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — co-IP with domain mapping, functional migration assay, Ca2+-dependent regulation; single lab\",\n      \"pmids\": [\"39210440\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"Munc13-4 collaborates with HRS, Rab27, and SNAREs to facilitate PD-L1 sorting and secretion via exosomes in tumor cells, mediating immune evasion. PD-L1 sorting relies on a ternary Munc13-4–PD-L1–HRS complex regulated by IFNγ signaling. Cryo-EM analysis of the Munc13-4–Rab27a complex provided structural insights into exosome secretion. A designed peptide disrupting the Munc13-4–PD-L1 interaction inhibits PD-L1 exosomal sorting and enhances anti-tumor immunity.\",\n      \"method\": \"Cryo-EM structure of Munc13-4–Rab27a complex, co-immunoprecipitation (ternary complex), Munc13-4 deletion in tumor cells, exosome PD-L1 assay, designed peptide inhibition, in vivo tumor models\",\n      \"journal\": \"Nature communications\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — cryo-EM structure, ternary complex co-IP, functional tumor/immune assays, therapeutic peptide validation; multiple rigorous orthogonal methods\",\n      \"pmids\": [\"41083534\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"Munc13-4 is a central regulator of crinophagy (secretory granule–lysosome fusion) in mammalian endocrine cells. siRNA screening identified Munc13-4 as required for SG-lysosome merge along with Rab27A, VAMP2, PLEKHM1, HOPS subunits, and SNAREs STX7, STX8, VTI1B. SG-lysosome fusion is regulated by local or global calcium through binding and activation of Munc13-4.\",\n      \"method\": \"siRNA screen with live-cell SG-lysosome merge assay, Ca2+ manipulation, identification of required components\",\n      \"journal\": \"Research square (preprint)\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — siRNA screen plus live-cell assay; preprint, not yet peer-reviewed; single study\",\n      \"pmids\": [\"40951263\"],\n      \"is_preprint\": true\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"Small-molecule ENDOtollins (ENDOs) that inhibit the Munc13-4–STX7 interaction reduce endolysosomal flux, impair endosomal TLR3/7/9 signaling in dendritic cells and ERK signaling in neutrophils in response to endosomal (but not plasma membrane) TLR ligands, and reduce CpG-induced systemic inflammation in vivo. This establishes the Munc13-4–STX7 interaction as mechanistically required for endosomal TLR signaling.\",\n      \"method\": \"High-throughput compound screen, orthogonal cell-based validation, endolysosomal flux assay, TLR signaling assays, in vivo CpG inflammation model, chemical optimization\",\n      \"journal\": \"Nature chemical biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — pharmacological target validation with small molecules, in vitro mechanistic assays, and in vivo model; multiple orthogonal methods establishing Munc13-4–STX7 as required for endosomal TLR pathway\",\n      \"pmids\": [\"41942734\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"A C-terminal C2B domain truncation mutation in Munc13-4 (p.Arg899X; Munc13-4(1-899)) correctly targets to CD63+ secretory lysosomes but shows reduced stability, uncoupled dynamic turnover on granule membrane, and fails to rescue degranulation in cells with silenced endogenous Munc13-4. This demonstrates that the C-terminal C2B domain is essential for Munc13-4 function.\",\n      \"method\": \"Ectopic expression of truncation mutant in patient/silenced cells, CD63 co-localization, protein stability assay, degranulation rescue assay\",\n      \"journal\": \"Pediatric blood & cancer\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — functional domain mapping via patient-derived mutation, rescue assay, localization; single lab\",\n      \"pmids\": [\"21755595\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"In airway epithelial cells, Munc13-4 (but not Munc13-2) is specifically recruited to the plasma membrane and increases its interaction with syntaxin 2 in response to human neutrophil elastase (hNE) stimulation. Munc13-4 siRNA knockdown reduces hNE-stimulated MUC5AC secretion while increasing intracellular MUC5AC retention, indicating Munc13-4 mediates hNE-stimulated airway mucin hypersecretion via syntaxin 2.\",\n      \"method\": \"Co-immunoprecipitation (Munc13-4–syntaxin 2), siRNA knockdown, ELISA for MUC5AC secretion, immunofluorescence, Western blotting\",\n      \"journal\": \"Molecular medicine reports\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single co-IP and siRNA in cell lines; single lab, limited mechanistic depth\",\n      \"pmids\": [\"29767240\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"Munc13-4 is required for TNF production (not just secretion) in activated RBL-2H3 mast cells. Munc13-4 KO cells show absent antigen/IgE-induced TNF production, restored by Munc13-4 re-expression. A TNF receptor antagonist blocks TNF production without inhibiting release, revealing a TNF autocrine feed-back loop that requires Munc13-4.\",\n      \"method\": \"Munc13-4 KO cell line, rescue by re-expression, ELISA for TNF secretion and intracellular levels, TNF receptor antagonist\",\n      \"journal\": \"Inflammation\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — KO with rescue and pharmacological dissection; single lab\",\n      \"pmids\": [\"31897916\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"Munc13-4 (UNC13D) is a dual C2-domain Ca2+ sensor and vesicle priming/tethering factor that, upon Ca2+ elevation, binds phospholipids and SNARE proteins (syntaxin 7/VAMP8 at late endosomes; exocytic SNAREs at the plasma membrane) to promote SNARE-dependent membrane fusion; it is recruited to secretory lysosomes, dense-core granules, multivesicular bodies, and Weibel-Palade bodies through direct GTP-Rab27a/b and Rab11 interactions, where it tethers vesicles at the plasma membrane and primes them for Ca2+-triggered exocytosis across hematopoietic and non-hematopoietic cells, while also regulating late endosomal maturation, phagosomal function, TLR9/endosomal innate immune signaling, exosomal PD-L1 secretion, and autophagy via a TFEB-dependent pathway.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"Munc13-4 (UNC13D) is a Ca2+-dependent vesicle tethering and priming factor that drives SNARE-mediated membrane fusion in regulated secretory and endolysosomal pathways across hematopoietic and non-hematopoietic cells [#0, #9]. It is essential for the priming step of cytolytic granule secretion in cytotoxic lymphocytes that precedes membrane fusion, and loss-of-function mutations in UNC13D cause familial hemophagocytic lymphohistiocytosis type 3 (FHL3) [#0]. Munc13-4 senses Ca2+ through its tandem C2A and C2B domains: C2A supports Ca2+-stimulated SNARE binding while C2B drives Ca2+-dependent membrane binding, and together these domains enable Munc13-4 to promote Ca2+-triggered SNARE complex formation and SNARE-dependent liposome fusion [#9, #22]. As a monomeric prolate ellipsoid able to bridge two membranes, it acts as a Ca2+-dependent tether that corrals motile secretory vesicles beneath the plasma membrane and clusters acidic-phospholipid membranes [#16, #8]. Recruitment to target organelles occurs through direct binding to GTP-loaded Rab27a/Rab27b via a non-canonical N-terminal Rab27-binding motif, and through Rab11, linking Munc13-4 to dense-core granules, secretory lysosomes, and recycling endosomes [#1, #8, #15]. Beyond exocytosis, Munc13-4 binds the endosomal SNARE syntaxin 7 (and VAMP8) to govern late endosomal maturation and endosomal TLR signaling, a function pharmacologically validated as required for endosomal TLR3/7/9 responses [#17, #31]. This broad fusion-machinery role underlies its requirement in cytotoxic lymphocyte killing, platelet dense/alpha-granule release and hemostasis, neutrophil granule exocytosis and phagosomal maturation, mast cell degranulation, Weibel-Palade body exocytosis, and tumor-associated exosomal PD-L1 secretion [#7, #10, #20, #29].\",\n  \"teleology\": [\n    {\n      \"year\": 2003,\n      \"claim\": \"Established Munc13-4 as the priming factor whose loss causes a human immunodeficiency, defining its role in regulated secretion and placing it upstream of membrane fusion in cytotoxic granule exocytosis.\",\n      \"evidence\": \"Patient UNC13D mutation analysis, tagged-protein localization, and exocytosis assays in cytotoxic T lymphocytes\",\n      \"pmids\": [\"14622600\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Molecular fusion mechanism not defined at this stage\", \"No biochemical reconstitution of the priming activity\"]\n    },\n    {\n      \"year\": 2003,\n      \"claim\": \"Identified Munc13-4 as the direct effector of GTP-Rab27, explaining how the secretory machinery is recruited to and activated at granules.\",\n      \"evidence\": \"Affinity purification, in vitro recombinant binding assay, and permeabilized platelet secretion rescue\",\n      \"pmids\": [\"14699162\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Binding interface on Munc13-4 not mapped\", \"Did not establish how Rab27 binding couples to fusion\"]\n    },\n    {\n      \"year\": 2006,\n      \"claim\": \"Mapped specific Munc13-4 residues required for stable Rab27a complex formation, linking disease mutations to loss of effector binding.\",\n      \"evidence\": \"Mammalian two-hybrid analysis of the L403P missense mutant\",\n      \"pmids\": [\"16278825\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Two-hybrid only; no structural or biophysical binding measurement\", \"Functional secretion consequence not directly tested here\"]\n    },\n    {\n      \"year\": 2008,\n      \"claim\": \"Extended Munc13-4 function beyond lymphocytes to neutrophil and mast cell granule exocytosis and identified Ca2+-regulated membrane recruitment and a Doc2alpha partner.\",\n      \"evidence\": \"Cell fractionation, immunofluorescence, siRNA/KO mouse cells, phospholipid binding, and reciprocal co-IP\",\n      \"pmids\": [\"18453599\", \"18354201\", \"18939952\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Precise SNARE machinery engaged not yet defined\", \"Relative contribution of Ca2+ vs Rab recruitment not resolved\"]\n    },\n    {\n      \"year\": 2009,\n      \"claim\": \"Showed receptor-specific, Rab27a-dependent recruitment of Munc13-4 to lytic granules, revealing signal-dependent control of where the machinery assembles.\",\n      \"evidence\": \"Confocal colocalization in primary and patient-derived NK cells with defined receptor stimulation\",\n      \"pmids\": [\"19704116\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Mechanism of differential receptor coupling unknown\", \"Single-lab, imaging-based\"]\n    },\n    {\n      \"year\": 2011,\n      \"claim\": \"Defined the Munc13-4-Rab27a complex as a tether that corrals motile secretory lysosomes at the plasma membrane and mapped a non-canonical Rab27a-binding motif required for degranulation.\",\n      \"evidence\": \"Rab27a-binding motif mutagenesis, FHL3 patient CTL complementation, mast cell rescue, and TIRF imaging; C-terminal C2B truncation analysis\",\n      \"pmids\": [\"21693760\", \"21755595\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Tethering vs priming activities not biochemically separated here\", \"Structural basis of motif recognition not solved\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Demonstrated biochemically that Munc13-4 is a Ca2+ sensor that promotes Ca2+-dependent SNARE complex formation and SNARE-mediated liposome fusion via its C2 domains, the first such priming factor activity reconstituted in vitro.\",\n      \"evidence\": \"In vitro Ca2+ binding, C2 Ca2+-residue mutagenesis, SNARE binding, liposome fusion reconstitution, and permeable cell exocytosis assays\",\n      \"pmids\": [\"22508512\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Identity of physiological SNAREs at each compartment not fully resolved\", \"Stoichiometry of fusion machinery not defined\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Revealed Rab27a-independent Munc13-4 functions in phagosomal maturation/bacterial killing and PIP2/AP-2-dependent endocytic recycling needed to sustain serial killing.\",\n      \"evidence\": \"Munc13-4 KO mouse neutrophils with Rab27a KO comparison; PIP5K-gamma silencing, raft fractionation, and serial killing assays\",\n      \"pmids\": [\"23115246\", \"22271450\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"How Munc13-4 is recruited independently of Rab27a not defined\", \"Recycling-pathway role rests on single-lab Medium evidence\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Established genetic epistasis placing Munc13-4 downstream of Rab27b (not only Rab27a) in mast cell degranulation.\",\n      \"evidence\": \"Multiple KO mouse BMMC models with double-knockout degranulation assays\",\n      \"pmids\": [\"23281710\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Tissue-specific Rab27 isoform preference mechanism unclear\", \"Single study\"]\n    },\n    {\n      \"year\": 2014,\n      \"claim\": \"Defined transcriptional control of UNC13D through an intronic enhancer/alternative promoter, showing how non-coding disease variants reduce Munc13-4 expression.\",\n      \"evidence\": \"EMSA, ChIP, reporter assays, and patient PBMC qPCR identifying ELF1/STAT4/BRG1 regulation and the c.118-308C>T variant; complementary Rab27a-side interaction mapping\",\n      \"pmids\": [\"24842371\", \"25312756\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Full set of regulatory inputs not enumerated\", \"Rab27a-side mapping is Medium-confidence patient-mutation work\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"Expanded the partner repertoire to Rab11 and the endosomal SNARE syntaxin 7/VAMP8, establishing Munc13-4 roles in recycling-endosome trafficking and late endosomal maturation distinct from classical exocytosis.\",\n      \"evidence\": \"TR-FRET/co-IP binding, super-resolution and live-cell imaging, KO neutrophils, Ca2+-binding and STX7-binding mutant rescue; AUC and proteoliposome fusion\",\n      \"pmids\": [\"26637356\", \"26637270\", \"26680738\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"How a single Munc13-4 selects among Rab11/Rab27/SNARE partners not resolved\", \"Structural basis of monomeric membrane bridging inferred from AUC dimensions\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Identified a Rab27-Munc13-4-Rab37 ternary complex through which Rab37 negatively regulates degranulation, adding a brake to the priming machinery.\",\n      \"evidence\": \"Co-IP, siRNA epistasis, and degranulation assays in RBL-2H3 cells\",\n      \"pmids\": [\"26931073\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"GTP-independent Rab37 binding mechanism unexplained\", \"Single-lab\"]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Showed Munc13-4 catalyzes both heterotypic granule-plasma membrane and homotypic granule-granule fusion and engages late endosomal SNARE complexes, broadening its fusion-machinery role; also defined it as a Weibel-Palade body tether in endothelium.\",\n      \"evidence\": \"Liposome fusion with exocytic and endosomal Q-SNAREs, Ca2+-binding mutants, TIRF imaging; TIRF/co-IP and VWF secretion assays with S100A10\",\n      \"pmids\": [\"28100639\", \"28450451\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Recruitment determinants in endothelial cells (S100A10 role) Medium-confidence\", \"Switch between homotypic and heterotypic fusion not mechanistically defined\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Confirmed both C2 domains as functionally required Ca2+ sensors controlling fusion-pore Ca2+ sensitivity, and established Munc13-4 as a rate-limiting determinant of platelet-driven thrombosis and inflammation in vivo.\",\n      \"evidence\": \"C2A/C2B aspartate mutagenesis with single-granule TIRF and cytotoxicity in NK cells; platelet-specific conditional KO with thrombosis, bleeding, and airway inflammation models\",\n      \"pmids\": [\"29884704\", \"29674495\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Quantitative Ca2+-sensing model across cell types incomplete\", \"Indirect alpha-granule effect mechanism not resolved\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Extended UNC13D dysregulation to additional non-coding disease variants and to autocrine TNF production in mast cells.\",\n      \"evidence\": \"EMSA/enhancer reporter and patient PBMC analysis of the NF-kB-disrupting c.117+143A>G variant; KO/rescue and TNF receptor antagonist in RBL-2H3 cells\",\n      \"pmids\": [\"29409136\", \"31897916\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"How a secretion factor controls cytokine production not mechanistically defined\", \"Single-lab studies\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Linked Munc13-4 endosomal function to autophagy regulation via a TFEB-dependent program, connecting endolysosomal trafficking to lysosomal biogenesis.\",\n      \"evidence\": \"KO cells with WT vs STX7-binding-mutant rescue, autophagy flux assays, TFEB knockdown, and a cystinosis cell model\",\n      \"pmids\": [\"30892133\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct vs indirect link to TFEB unresolved\", \"Single-lab\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Resolved the functional significance of UNC13D isoforms, showing the alternative N-terminal isoform is interchangeable for localization and exocytic rescue.\",\n      \"evidence\": \"Isoform-specific antibodies and FHL3 patient T cell complementation\",\n      \"pmids\": [\"32582217\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Possible isoform-specific functions outside exocytosis untested\", \"Single-lab\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Demonstrated a Munc13-4-dependent Ca2+-stimulated exosome release pathway controlling MVB biogenesis and tumor matrix degradation through Rab11-dependent trafficking.\",\n      \"evidence\": \"siRNA knockdown, Ca2+-binding mutant rescue, CD63-pHluorin imaging, MVB morphology, MT1-MMP trafficking and ECM degradation assays\",\n      \"pmids\": [\"29930202\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"How Munc13-4 directs MVB-versus-secretory fates not defined\", \"Cancer-cell specificity of the pathway not established\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Uncovered a non-secretory regulatory role at the ER, where UNC13D restrains STING oligomerization and DNA-sensing innate immune signaling.\",\n      \"evidence\": \"Co-localization, co-IP/domain mapping, KO/KD cells, IFN-beta readouts, and STING inhibitor rescue\",\n      \"pmids\": [\"36125406\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"How a fusion factor localizes to ER and inhibits STING unclear\", \"Single-lab\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Defined a RAB11-UNC13D-FAK axis coupling recycling-endosome exocytosis to focal adhesion turnover and cancer cell migration.\",\n      \"evidence\": \"Co-IP/FERM-domain mapping, Ca2+-dependent FAK phosphorylation, and migration assays\",\n      \"pmids\": [\"39210440\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct FAK interaction needs structural validation\", \"Single-lab\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Provided structural insight into the Munc13-4-Rab27a complex and defined a Munc13-4-PD-L1-HRS ternary complex driving exosomal PD-L1 secretion and immune evasion, validated by a disruptive peptide.\",\n      \"evidence\": \"Cryo-EM of Munc13-4-Rab27a, ternary co-IP, tumor-cell deletion, exosome PD-L1 assays, peptide inhibition, and in vivo tumor models\",\n      \"pmids\": [\"41083534\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Atomic interface of PD-L1/HRS engagement not resolved\", \"Generality across tumor types untested\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Implicated Munc13-4 as a central regulator of crinophagy via secretory granule-lysosome fusion in endocrine cells.\",\n      \"evidence\": \"siRNA screen with live-cell SG-lysosome merge assay and Ca2+ manipulation (preprint)\",\n      \"pmids\": [\"40951263\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Preprint, not yet peer-reviewed\", \"Direct binding to the identified HOPS/SNARE machinery not biochemically shown\"]\n    },\n    {\n      \"year\": 2026,\n      \"claim\": \"Pharmacologically validated the Munc13-4-STX7 interaction as mechanistically required for endolysosomal flux and endosomal TLR signaling, establishing it as a druggable inflammatory node.\",\n      \"evidence\": \"Small-molecule (ENDOtollin) inhibitors, endolysosomal flux and TLR signaling assays, and an in vivo CpG inflammation model\",\n      \"pmids\": [\"41942734\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Selectivity of Munc13-4-STX7 disruption versus other SNARE interactions not fully mapped\", \"Long-term consequences of chronic inhibition unknown\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How a single Munc13-4 protein integrates competing Rab (Rab27a/b, Rab11, Rab37) and SNARE (exocytic vs syntaxin 7/VAMP8) partners to select among exocytosis, endosomal maturation, autophagy, and ER-based STING regulation in a cell-type- and signal-specific manner remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No unified structural/biophysical model of partner selection\", \"Mechanism of compartment-specific recruitment incompletely defined\", \"Non-secretory ER/STING role mechanistically isolated\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0140299\", \"supporting_discovery_ids\": [9, 16, 22]},\n      {\"term_id\": \"GO:0008289\", \"supporting_discovery_ids\": [3, 9, 16]},\n      {\"term_id\": \"GO:0060090\", \"supporting_discovery_ids\": [8, 16, 19]},\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [1, 9, 17]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005829\", \"supporting_discovery_ids\": [3]},\n      {\"term_id\": \"GO:0005886\", \"supporting_discovery_ids\": [3, 8, 33]},\n      {\"term_id\": \"GO:0005768\", \"supporting_discovery_ids\": [15, 17, 25]},\n      {\"term_id\": \"GO:0005764\", \"supporting_discovery_ids\": [4, 8, 30]},\n      {\"term_id\": \"GO:0031410\", \"supporting_discovery_ids\": [0, 1, 20]},\n      {\"term_id\": \"GO:0005783\", \"supporting_discovery_ids\": [27]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-5653656\", \"supporting_discovery_ids\": [0, 7, 9]},\n      {\"term_id\": \"R-HSA-168256\", \"supporting_discovery_ids\": [0, 10, 31]},\n      {\"term_id\": \"R-HSA-109582\", \"supporting_discovery_ids\": [7, 23]},\n      {\"term_id\": \"R-HSA-9612973\", \"supporting_discovery_ids\": [25]},\n      {\"term_id\": \"R-HSA-9609507\", \"supporting_discovery_ids\": [15, 17, 21]}\n    ],\n    \"complexes\": [\n      \"Munc13-4-Rab27a complex\",\n      \"Rab27-Munc13-4-Rab37 ternary complex\",\n      \"Munc13-4-PD-L1-HRS complex\",\n      \"RAB11-UNC13D-FAK complex\"\n    ],\n    \"partners\": [\n      \"RAB27A\",\n      \"RAB27B\",\n      \"RAB11A\",\n      \"STX7\",\n      \"VAMP8\",\n      \"DOC2A\",\n      \"STING1\",\n      \"PTK2\"\n    ],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":7,"faith_total":7,"faith_pct":100.0}}