{"gene":"CRADD","run_date":"2026-06-09T22:57:19","timeline":{"discoveries":[{"year":1997,"finding":"RAIDD/CRADD is a bipartite adaptor molecule: its C-terminal death domain (DD) binds the DD of RIP (a serine/threonine kinase), and its N-terminal CARD (caspase recruitment domain, homologous to ICE/CED-3 prodomains) mediates homophilic binding to caspase-2 (ICH-1) and C. elegans CED-3, directly linking death proteases to signaling pathways.","method":"Yeast two-hybrid, co-immunoprecipitation, domain mapping with mutations equivalent to inactivating ced-3 mutations","journal":"Nature","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal binding assays with domain mutants, independently replicated in same year by separate lab (PMID:9044836)","pmids":["8985253"],"is_preprint":false},{"year":1997,"finding":"CRADD has an NH2-terminal caspase homology domain that interacts with caspase-2 and a COOH-terminal death domain that interacts with RIP, and CRADD is constitutively expressed in many tissues.","method":"Co-immunoprecipitation, domain deletion constructs, overexpression apoptosis assay","journal":"Cancer research","confidence":"High","confidence_rationale":"Tier 2 / Strong — independent replication of RAIDD mechanism by separate lab using reciprocal co-IP and domain mapping","pmids":["9044836"],"is_preprint":false},{"year":1998,"finding":"NMR solution structure of the RAIDD CARD reveals six tightly packed helices in a topology homologous to the Fas death domain, with a basic patch and an acidic patch on opposite sides that mediate CARD/CARD interaction with ICH-1/caspase-2; mutagenesis of these patches disrupts the interaction.","method":"NMR structure determination, homology modeling, mutagenesis","journal":"Cell","confidence":"High","confidence_rationale":"Tier 1 / Strong — high-resolution NMR structure combined with mutagenesis validating the interaction surface","pmids":["9695946"],"is_preprint":false},{"year":2000,"finding":"Endogenous RAIDD localizes predominantly to the cytoplasm and, to a lesser extent, the nucleus; co-expression with caspase-2 recruits a fraction of RAIDD to the nucleus and causes CARD-dependent colocalization at discrete subcellular structures. Overexpression of the RAIDD-CARD alone forms filamentous oligomeric structures similar to death effector filaments, partially colocalizing with FADD/FLICE DEFs, suggesting CARD-mediated higher-order complex formation is regulated by intramolecular folding.","method":"Subcellular fractionation, immunofluorescence/confocal microscopy, transfection of domain mutants","journal":"Cell death and differentiation","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — direct localization experiments with functional domain dissection, single lab, multiple imaging approaches","pmids":["10713730"],"is_preprint":false},{"year":2005,"finding":"PIDD-induced apoptosis and growth suppression in embryonic fibroblasts require the adaptor protein RAIDD; RAIDD-deficient MEFs are resistant to PIDD-induced cell death, which is associated with early activation of caspase-2 and later activation of caspases-3 and -7. Caspase-2 knockout MEFs are only partially resistant, indicating caspase-2 contributes but is not the sole effector downstream of RAIDD.","method":"Genetic knockout (RAIDD-/- and caspase-2-/- MEFs), caspase activity assays, cell death assays","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"High","confidence_rationale":"Tier 2 / Moderate — clean genetic epistasis using knockout cells with defined apoptotic readouts and caspase activity measurements","pmids":["16183742"],"is_preprint":false},{"year":2000,"finding":"RAIDD is dispensable for Fas ligand-induced apoptosis in lymphoid cells; loss of RAIDD does not affect FasL-mediated cell death.","method":"Genetic studies in RAIDD-deficient cells, cell death assays","journal":"Journal of immunology","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — negative finding from knockout/deficient cells, single study","pmids":["10903735"],"is_preprint":false},{"year":2006,"finding":"Crystal structure of the RAIDD death domain determined at 2.0 Å resolution, revealing structural features important for DD folding, dynamics, and PIDDosome assembly via DD:DD interaction with PIDD.","method":"X-ray crystallography at 2.0 Å resolution","journal":"Journal of molecular biology","confidence":"High","confidence_rationale":"Tier 1 / Moderate — high-resolution crystal structure, single lab but rigorous structural method","pmids":["16434054"],"is_preprint":false},{"year":2004,"finding":"RAIDD interacts with rat caspase-2 via CARD-CARD interaction in neuronal (PC12) cells; RAIDD overexpression induces caspase-2 CARD- and caspase-9-dependent apoptosis in PC12 cells and sympathetic neurons, correlating with formation of discrete perinuclear aggregates; full-length RAIDD is required for both death and aggregate formation.","method":"Co-immunoprecipitation, overexpression with domain mutants, cell death assays, fluorescence microscopy","journal":"Cell death and differentiation","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — reciprocal interaction assays combined with domain deletion and phenotypic readouts, single lab","pmids":["14765136"],"is_preprint":false},{"year":2006,"finding":"Endogenous RAIDD is required for trophic factor withdrawal-induced apoptosis of PC12 cells and sympathetic neurons; siRNA knockdown of RAIDD inhibits trophic deprivation-induced death but not DNA damage-induced (non-caspase-2-mediated) death, indicating RAIDD acts specifically through caspase-2 in this context.","method":"siRNA knockdown, dominant-negative CARD fragment expression, cell death assays","journal":"Cell death and differentiation","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — loss-of-function via siRNA with specific pathway controls, single lab","pmids":["15947787"],"is_preprint":false},{"year":2007,"finding":"The PIDD DD–RAIDD DD complex forms an oligomeric assembly of ~150 kDa in solution (as measured by gel filtration and MALS), mediated by homotypic DD:DD interactions; the complex was crystallized and diffracted to 3.2 Å.","method":"Recombinant protein purification, gel filtration, multi-angle light scattering (MALS), crystallography","journal":"Acta crystallographica Section F","confidence":"Medium","confidence_rationale":"Tier 1 / Weak — biochemical reconstitution of complex with size determination, crystallography preliminary data, single lab","pmids":["17329820"],"is_preprint":false},{"year":2010,"finding":"PIDDosome assembly is time-dependent and salt concentration-dependent; point mutations R147E in RAIDD and Y814A in PIDD exert dominant-negative effects on PIDDosome formation but cannot disrupt pre-formed PIDDosome complexes.","method":"Recombinant protein purification, biochemical assembly assays, site-directed mutagenesis","journal":"Biochimica et biophysica acta","confidence":"Medium","confidence_rationale":"Tier 1 / Weak — in vitro reconstitution with mutagenesis, single lab","pmids":["20406701"],"is_preprint":false},{"year":2011,"finding":"In ATLL cells, LBH589 (HDAC inhibitor) activates apoptosis via a RAIDD-initiated pathway; siRNA knockdown experiments showed RAIDD activation is the initiating event upstream of caspase-2 and caspase-9 in this context, and RIPK1 is also required.","method":"siRNA knockdown of RAIDD, PIDD, caspase-2, caspase-9, and RIPK1; caspase activity assays; DNA microarray","journal":"Leukemia","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — loss-of-function siRNA epistasis with caspase activity readouts, single lab","pmids":["21242994"],"is_preprint":false},{"year":2012,"finding":"In neurons, caspase-2 activation and caspase-2-dependent neuronal death induced by NGF deprivation or Aβ treatment require RAIDD but not PIDD; RAIDD and caspase-2 form a complex in neurons treated with these stimuli, demonstrable by co-immunoprecipitation from PIDD-null neurons.","method":"Genetic knockout (RAIDD-/- and PIDD-/- neurons), active caspase-2 detection, co-immunoprecipitation, cell death assays","journal":"The Biochemical journal","confidence":"High","confidence_rationale":"Tier 2 / Moderate — clean genetic epistasis with two distinct knockouts, reciprocal Co-IP showing complex formation, multiple stimuli tested","pmids":["22515271"],"is_preprint":false},{"year":2012,"finding":"CRADD interacts with BCL10 through its CARD domain and suppresses the BCL10-CARMA1 interaction; TCR agonist stimulation induces CRADD-BCL10 interaction coincident with reduced BCL10-CARMA1 complex formation; Cradd-deficient T cells and mice produce significantly higher levels of IFN-γ, IL-2, TNF-α, and IL-17 in response to TCR agonists.","method":"Co-immunoprecipitation, Cradd-/- primary cells and mice, cytokine measurement","journal":"Journal of immunology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — reciprocal Co-IP showing CARD-dependent BCL10 binding, genetic knockout with quantified cytokine output, single lab","pmids":["22323537"],"is_preprint":false},{"year":2013,"finding":"PIDD DD mediates and stabilizes the interaction between RAIDD and caspase-2 during PIDDosome assembly: full-length RAIDD in a 'closed' conformation cannot interact with caspase-2 CARD alone; PIDD DD must first bind RAIDD DD to open RAIDD and allow subsequent recruitment of caspase-2 via CARD:CARD interaction.","method":"Recombinant protein purification, solubility/binding assays, biochemical reconstitution of the sequential assembly","journal":"BMB reports","confidence":"Medium","confidence_rationale":"Tier 1 / Weak — in vitro reconstitution revealing ordered assembly mechanism, single lab","pmids":["24064063"],"is_preprint":false},{"year":2014,"finding":"HDAC1 directly binds the CRADD promoter and downregulates CRADD expression; TSA (HDAC inhibitor) induces CRADD expression to activate caspase-2-dependent apoptosis; HDAC1 siRNA upregulates CRADD in gastric cancer cells.","method":"ChIP assay (HDAC1 binding to CRADD promoter), siRNA knockdown, caspase-2 activity assays, Western blot","journal":"American journal of translational research","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — ChIP demonstrating direct promoter binding, functional siRNA rescue, single lab","pmids":["25360218"],"is_preprint":false},{"year":2014,"finding":"CRADD-deficient murine endothelial cells show heightened BCL10-mediated IL-6 and MCP-1 expression and increased permeability in response to LPS and thrombin, with increased F-actin polymerization and disrupted adherens junctions; delivery of cell-penetrating CP-CRADD protein restores barrier function and suppresses cytokine induction, defining CRADD as an inducible suppressor of BCL10 in endothelial cells.","method":"Cradd-/- primary endothelial cells, permeability assays, F-actin staining, recombinant CP-CRADD protein delivery, cytokine measurement","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — genetic knockout with multiple phenotypic readouts (permeability, cytokines, cytoskeleton) and rescue with recombinant protein, single lab","pmids":["24958727"],"is_preprint":false},{"year":2015,"finding":"The tumor-modulatory effects of Caspase-2 and Pidd1 in the Eμ-Myc lymphoma model do not require Raidd; Eμ-Myc/Raidd-/- mice show no protection from c-Myc-driven lymphomagenesis, uncoupling Raidd from Caspase-2's tumor suppressor function and Pidd1's tumor-promoting function.","method":"Eμ-Myc/Raidd-/- mouse model, tumor onset monitoring, genetic epistasis","journal":"Cell death and differentiation","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — clean in vivo genetic epistasis in mouse cancer model, single lab, negative result for Raidd's role","pmids":["25857265"],"is_preprint":false},{"year":2016,"finding":"RAIDD interacts with IRF7 and its kinase IKKε by co-immunoprecipitation; RAIDD-deficient cells show dramatically reduced type I IFN activation by IKKε and IRF7; deletion of either the CARD or DD of RAIDD inhibits IKKε/IRF7-mediated IFN-4α activation, indicating both domains are required for this function.","method":"Immunoprecipitation, shRNA lentiviral knockdown, IFN-driven dual luciferase reporter assay, domain deletion constructs","journal":"Cellular physiology and biochemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP showing molecular interaction with IRF7/IKKε, loss-of-function with luciferase reporter and domain mutants, single lab","pmids":["27606466"],"is_preprint":false},{"year":2016,"finding":"CRADD death domain mutations (G128R, F164C, R170C, R170H) found in thin lissencephaly patients do not disrupt interactions with caspase-2 or PIDD in co-immunoprecipitation assays, but still abolish CRADD's ability to activate caspase-2, resulting in reduced neuronal apoptosis in vitro; homozygous Cradd knockout mice display megalencephaly and seizures, establishing CRADD/caspase-2 signaling as required for normal cortical gyration.","method":"Co-immunoprecipitation of mutant CRADD with PIDD and caspase-2, caspase-2 activity assays, Cradd-/- mouse phenotyping","journal":"American journal of human genetics","confidence":"High","confidence_rationale":"Tier 2 / Strong — multiple disease mutations tested biochemically with Co-IP and functional caspase assay, corroborated by in vivo knockout mouse phenotype","pmids":["27773430"],"is_preprint":false},{"year":2016,"finding":"TAT-fused peptides containing wild-type helix 3 (H3) from RAIDD block PIDDosome formation in vitro and inhibit rotenone-induced caspase-2-dependent apoptosis in neuronal cells, demonstrating that the H3 region of RAIDD is critical for PIDDosome assembly.","method":"In vitro PIDDosome assembly assay, cell-penetrating peptide inhibition, caspase-2 activity assay in neuronal cells","journal":"Scientific reports","confidence":"Medium","confidence_rationale":"Tier 1 / Weak — in vitro reconstitution blockade combined with cell-based functional assay, single lab","pmids":["27502430"],"is_preprint":false},{"year":2018,"finding":"TLIS-associated RAIDD DD mutations (G128R, F164C, R170C, R170H) were analyzed biochemically; mutagenesis and binding assays revealed the molecular basis by which these mutations impair caspase-2 activation while leaving PIDD/caspase-2 interaction partially intact.","method":"Site-directed mutagenesis, recombinant protein expression, biochemical binding assays","journal":"PloS one","confidence":"Medium","confidence_rationale":"Tier 1 / Weak — mutagenesis with biochemical assays, single lab, extends prior structural work","pmids":["30281648"],"is_preprint":false}],"current_model":"CRADD/RAIDD is a bipartite adaptor protein with an N-terminal CARD and a C-terminal death domain: the DD binds the DD of PIDD (and RIP/RIPK1), while the CARD mediates homophilic interaction with the prodomain of caspase-2, assembling the PIDDosome complex in which PIDD-DD binding to RAIDD-DD is required first to open RAIDD and allow caspase-2 CARD recruitment, leading to proximity-induced caspase-2 dimerization and activation that drives apoptosis in neurons and stress-induced contexts; beyond apoptosis, CRADD also suppresses inflammatory signaling by binding BCL10 through its CARD to inhibit the CARMA1/CARMA3 signalosome, and coordinates type I interferon production by scaffolding IKKε–IRF7 interactions through both its CARD and DD."},"narrative":{"mechanistic_narrative":"CRADD (RAIDD) is a bipartite adaptor protein that links death proteases to upstream signaling through two homotypic interaction modules: a C-terminal death domain (DD) that binds the DD of RIP/RIPK1 and PIDD, and an N-terminal CARD that homophilically engages the prodomain of caspase-2 [PMID:8985253, PMID:9044836]. Structural work defined both modules — the CARD as a six-helix bundle with opposing basic and acidic patches that constitute the caspase-2 interaction surface [PMID:9695946], and the DD by crystallography as the unit driving PIDDosome assembly [PMID:16434054]. CRADD nucleates the PIDDosome through an ordered, conformationally gated mechanism: PIDD-DD must first bind the RAIDD-DD to open the otherwise closed full-length adaptor, permitting subsequent CARD:CARD recruitment of caspase-2 and proximity-induced caspase activation [PMID:24064063, PMID:17329820, PMID:20406701]. This adaptor function drives apoptosis in specific contexts, most prominently neuronal death following trophic factor withdrawal, NGF deprivation, or Aβ exposure, where RAIDD is required to assemble with and activate caspase-2 — in neurons independently of PIDD [PMID:15947787, PMID:22515271, PMID:16183742]. CRADD/caspase-2 signaling is required for normal cortical development: DD mutations (G128R, F164C, R170C, R170H) abolish caspase-2 activation while leaving PIDD/caspase-2 binding intact and cause thin/thick lissencephaly in patients, with Cradd-knockout mice showing megalencephaly and seizures [PMID:27773430, PMID:30281648]. Beyond apoptosis, CRADD restrains inflammatory signaling by binding BCL10 through its CARD to suppress the BCL10–CARMA1 signalosome, limiting cytokine output in T cells and endothelial barrier disruption [PMID:22323537, PMID:24958727], and it scaffolds IKKε–IRF7 interactions through both its CARD and DD to support type I interferon production [PMID:27606466]. CRADD is dispensable for Fas-mediated apoptosis and for the tumor-modulatory effects of caspase-2/PIDD1 in Myc-driven lymphoma, indicating its functions are pathway- and context-restricted [PMID:10903735, PMID:25857265].","teleology":[{"year":1997,"claim":"Established CRADD/RAIDD as a bipartite adaptor that physically bridges an upstream kinase to a death protease, answering how caspase-2 is connected to signaling complexes.","evidence":"Yeast two-hybrid, reciprocal co-immunoprecipitation, and domain mapping mapping the DD to RIP and the CARD to caspase-2/CED-3, independently replicated by a second lab the same year","pmids":["8985253","9044836"],"confidence":"High","gaps":["Did not define the physiological stimulus or higher-order assembly","RIP/RIPK1 functional role left uncharacterized"]},{"year":1998,"claim":"Defined the structural basis of CARD-mediated caspase-2 recruitment, identifying the charged surface patches that constitute the interaction interface.","evidence":"NMR solution structure of the RAIDD CARD with homology modeling and interface mutagenesis disrupting the caspase-2 interaction","pmids":["9695946"],"confidence":"High","gaps":["Structure of full-length adaptor and how CARD accessibility is regulated not resolved","No structure of the CARD:CARD complex itself"]},{"year":2000,"claim":"Showed CRADD function is pathway-restricted by establishing it is dispensable for Fas-induced apoptosis, and that its CARD drives higher-order oligomeric assemblies under intramolecular control.","evidence":"Cell death assays in RAIDD-deficient lymphoid cells; subcellular fractionation and confocal imaging of domain mutants forming filamentous structures","pmids":["10903735","10713730"],"confidence":"Medium","gaps":["Negative Fas result from a single study","Functional significance of CARD filaments in endogenous setting unclear"]},{"year":2004,"claim":"Connected CRADD to neuronal apoptosis, showing CARD-dependent caspase-2 recruitment drives death in neurons.","evidence":"Co-IP, domain mutants, cell death assays and microscopy in PC12 cells and sympathetic neurons showing full-length RAIDD is required for death and aggregate formation","pmids":["14765136"],"confidence":"Medium","gaps":["Relied on overexpression for the death phenotype","Endogenous requirement not yet demonstrated"]},{"year":2005,"claim":"Placed RAIDD genetically upstream in PIDD-induced death, establishing it as an obligate adaptor whose loss confers resistance.","evidence":"RAIDD-/- and caspase-2-/- MEFs with caspase activity and death assays showing RAIDD requirement and partial caspase-2 dependence","pmids":["16183742"],"confidence":"High","gaps":["Identity of caspase-2-independent effector downstream of RAIDD unknown"]},{"year":2006,"claim":"Demonstrated the endogenous physiological requirement for RAIDD in trophic-deprivation neuronal death and its stimulus specificity, distinguishing caspase-2-dependent from DNA-damage death.","evidence":"siRNA knockdown and dominant-negative CARD fragment expression with pathway-specific death assays; DD crystal structure at 2.0 Å","pmids":["15947787","16434054"],"confidence":"High","gaps":["Mechanism distinguishing trophic versus DNA-damage death routing not defined"]},{"year":2010,"claim":"Reconstituted the PIDDosome in vitro and characterized its oligomeric stoichiometry and assembly determinants, defining DD:DD contacts as the assembly driver.","evidence":"Recombinant protein purification, gel filtration, MALS, and dominant-negative point mutants (RAIDD R147E, PIDD Y814A) in biochemical assembly assays","pmids":["17329820","20406701"],"confidence":"Medium","gaps":["Did not capture caspase-2-incorporated complex","In vitro assembly kinetics may not reflect cellular regulation"]},{"year":2012,"claim":"Resolved the in vivo neuronal mechanism, showing RAIDD–caspase-2 complex assembly is required but PIDD is dispensable in neurons, and uncovered a non-apoptotic role suppressing BCL10–CARMA1 inflammatory signaling.","evidence":"RAIDD-/- and PIDD-/- neurons with active caspase-2 detection and co-IP; Cradd-/- T cells/mice with CARD-dependent BCL10 co-IP and cytokine measurement","pmids":["22515271","22323537"],"confidence":"High","gaps":["PIDD-independent neuronal scaffold for RAIDD not identified","How a single CARD partitions between caspase-2 and BCL10 binding unclear"]},{"year":2013,"claim":"Defined the ordered, conformationally gated assembly mechanism whereby PIDD-DD binding opens closed RAIDD to permit caspase-2 recruitment.","evidence":"Recombinant protein solubility/binding assays reconstituting sequential PIDDosome assembly","pmids":["24064063"],"confidence":"Medium","gaps":["Structural detail of the closed-to-open transition not visualized","In vitro model not validated in cells"]},{"year":2014,"claim":"Extended CRADD's anti-inflammatory BCL10-suppressing role to endothelial barrier control and established transcriptional regulation of CRADD by HDAC1.","evidence":"Cradd-/- endothelial cells with permeability, cytoskeletal and cytokine readouts plus CP-CRADD rescue; ChIP showing HDAC1 binding the CRADD promoter with siRNA functional rescue","pmids":["24958727","25360218"],"confidence":"Medium","gaps":["Single-lab studies","Direct competition between CRADD and CARMA1 for BCL10 not structurally defined"]},{"year":2016,"claim":"Established CRADD/caspase-2 signaling as required for normal cortical gyration and identified its role in type I interferon production.","evidence":"Co-IP of lissencephaly DD mutants with PIDD/caspase-2, caspase-2 activity assays and Cradd-/- mouse phenotyping; Co-IP and domain-deletion luciferase reporter assays mapping IKKε/IRF7 scaffolding to both CARD and DD","pmids":["27773430","27606466","27502430"],"confidence":"High","gaps":["How DD mutations abolish caspase-2 activation despite intact binding not mechanistically resolved","IKKε/IRF7 scaffolding mechanism single-lab"]},{"year":2018,"claim":"Provided the biochemical basis by which lissencephaly DD mutations impair caspase-2 activation while sparing PIDD/caspase-2 binding.","evidence":"Site-directed mutagenesis and recombinant binding assays of TLIS-associated DD mutants","pmids":["30281648"],"confidence":"Medium","gaps":["Mechanism couples binding-competent assembly to activation failure but lacks a structural model of the activating step"]},{"year":null,"claim":"How CRADD partitions a single CARD between pro-apoptotic caspase-2 recruitment and anti-inflammatory BCL10 sequestration, and how DD mutations uncouple PIDDosome binding from caspase-2 activation, remain unresolved.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No structure of the activated CARD:caspase-2 or CARD:BCL10 complex","Identity of the caspase-2-independent effector downstream of RAIDD unknown","Mechanistic coupling of assembly to caspase activation undefined"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0060090","term_label":"molecular adaptor activity","supporting_discovery_ids":[0,1,14]},{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[13,16,18]}],"localization":[{"term_id":"GO:0005829","term_label":"cytosol","supporting_discovery_ids":[3]},{"term_id":"GO:0005634","term_label":"nucleus","supporting_discovery_ids":[3]}],"pathway":[{"term_id":"R-HSA-5357801","term_label":"Programmed Cell Death","supporting_discovery_ids":[4,8,12]},{"term_id":"R-HSA-168256","term_label":"Immune System","supporting_discovery_ids":[13,16,18]}],"complexes":["PIDDosome"],"partners":["CASP2","PIDD1","RIPK1","BCL10","IRF7","IKBKE"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"P78560","full_name":"Death domain-containing protein CRADD","aliases":["Caspase and RIP adapter with death domain","RIP-associated protein with a death domain"],"length_aa":199,"mass_kda":22.7,"function":"Adapter protein that associates with PIDD1 and the caspase CASP2 to form the PIDDosome, a complex that activates CASP2 and triggers apoptosis (PubMed:15073321, PubMed:16652156, PubMed:17159900, PubMed:17289572, PubMed:9044836). Also recruits CASP2 to the TNFR-1 signaling complex through its interaction with RIPK1 and TRADD and may play a role in the tumor necrosis factor-mediated signaling pathway (PubMed:8985253)","subcellular_location":"Cytoplasm; Nucleus","url":"https://www.uniprot.org/uniprotkb/P78560/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/CRADD","classification":"Not Classified","n_dependent_lines":1,"n_total_lines":1208,"dependency_fraction":0.0008278145695364238},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/CRADD","total_profiled":1310},"omim":[{"mim_id":"620653","title":"INTELLECTUAL DEVELOPMENTAL DISORDER, AUTOSOMAL RECESSIVE 80, WITH VARIANT LISSENCEPHALY; MRT80","url":"https://www.omim.org/entry/620653"},{"mim_id":"619827","title":"INTELLECTUAL DEVELOPMENTAL DISORDER, AUTOSOMAL RECESSIVE 75, WITH NEUROPSYCHIATRIC FEATURES AND VARIANT LISSENCEPHALY; MRT75","url":"https://www.omim.org/entry/619827"},{"mim_id":"614499","title":"INTELLECTUAL DEVELOPMENTAL DISORDER, AUTOSOMAL RECESSIVE 34, WITH VARIANT LISSENCEPHALY; MRT34","url":"https://www.omim.org/entry/614499"},{"mim_id":"611649","title":"MINDY LYSINE-48 DEUBIQUITINASE 3; MINDY3","url":"https://www.omim.org/entry/611649"},{"mim_id":"606831","title":"NLR FAMILY, CASPASE RECRUITMENT DOMAIN-CONTAINING 4; NLRC4","url":"https://www.omim.org/entry/606831"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Approved","locations":[{"location":"Cytosol","reliability":"Approved"},{"location":"Nucleoplasm","reliability":"Additional"}],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in all","driving_tissues":[],"url":"https://www.proteinatlas.org/search/CRADD"},"hgnc":{"alias_symbol":["RAIDD"],"prev_symbol":[]},"alphafold":{"accession":"P78560","domains":[{"cath_id":"1.10.533.10","chopping":"2-94","consensus_level":"high","plddt":78.0754,"start":2,"end":94},{"cath_id":"1.10.533.10","chopping":"107-196","consensus_level":"high","plddt":86.5137,"start":107,"end":196}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/P78560","model_url":"https://alphafold.ebi.ac.uk/files/AF-P78560-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-P78560-F1-predicted_aligned_error_v6.png","plddt_mean":79.44},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=CRADD","jax_strain_url":"https://www.jax.org/strain/search?query=CRADD"},"sequence":{"accession":"P78560","fasta_url":"https://rest.uniprot.org/uniprotkb/P78560.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/P78560/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/P78560"}},"corpus_meta":[{"pmid":"8985253","id":"PMC_8985253","title":"RAIDD is a new 'death' adaptor molecule.","date":"1997","source":"Nature","url":"https://pubmed.ncbi.nlm.nih.gov/8985253","citation_count":457,"is_preprint":false},{"pmid":"9695946","id":"PMC_9695946","title":"Solution structure of the RAIDD CARD and model for CARD/CARD interaction in caspase-2 and caspase-9 recruitment.","date":"1998","source":"Cell","url":"https://pubmed.ncbi.nlm.nih.gov/9695946","citation_count":272,"is_preprint":false},{"pmid":"9044836","id":"PMC_9044836","title":"CRADD, a novel human apoptotic adaptor molecule for caspase-2, and FasL/tumor necrosis factor receptor-interacting protein RIP.","date":"1997","source":"Cancer research","url":"https://pubmed.ncbi.nlm.nih.gov/9044836","citation_count":226,"is_preprint":false},{"pmid":"16183742","id":"PMC_16183742","title":"Apoptosis caused by p53-induced protein with death domain (PIDD) depends on the death adapter protein RAIDD.","date":"2005","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/16183742","citation_count":89,"is_preprint":false},{"pmid":"10903735","id":"PMC_10903735","title":"Fas ligand-induced c-Jun kinase activation in lymphoid cells requires extensive receptor aggregation but is independent of DAXX, and Fas-mediated cell death does not involve DAXX, RIP, or RAIDD.","date":"2000","source":"Journal of immunology (Baltimore, Md. : 1950)","url":"https://pubmed.ncbi.nlm.nih.gov/10903735","citation_count":56,"is_preprint":false},{"pmid":"10713730","id":"PMC_10713730","title":"Subcellular localization and CARD-dependent oligomerization of the death adaptor RAIDD.","date":"2000","source":"Cell death and differentiation","url":"https://pubmed.ncbi.nlm.nih.gov/10713730","citation_count":52,"is_preprint":false},{"pmid":"27773430","id":"PMC_27773430","title":"Mutations in CRADD Result in Reduced Caspase-2-Mediated Neuronal Apoptosis and Cause Megalencephaly with a Rare Lissencephaly Variant.","date":"2016","source":"American journal of human genetics","url":"https://pubmed.ncbi.nlm.nih.gov/27773430","citation_count":51,"is_preprint":false},{"pmid":"21242994","id":"PMC_21242994","title":"LBH589, a deacetylase inhibitor, induces apoptosis in adult T-cell leukemia/lymphoma cells via activation of a novel RAIDD-caspase-2 pathway.","date":"2011","source":"Leukemia","url":"https://pubmed.ncbi.nlm.nih.gov/21242994","citation_count":44,"is_preprint":false},{"pmid":"22515271","id":"PMC_22515271","title":"Neuronal caspase 2 activity and function requires RAIDD, but not PIDD.","date":"2012","source":"The Biochemical journal","url":"https://pubmed.ncbi.nlm.nih.gov/22515271","citation_count":35,"is_preprint":false},{"pmid":"16434054","id":"PMC_16434054","title":"Crystal structure of RAIDD death domain implicates potential mechanism of PIDDosome assembly.","date":"2006","source":"Journal of molecular 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Part A","url":"https://pubmed.ncbi.nlm.nih.gov/28686357","citation_count":21,"is_preprint":false},{"pmid":"25857265","id":"PMC_25857265","title":"The tumor-modulatory effects of Caspase-2 and Pidd1 do not require the scaffold protein Raidd.","date":"2015","source":"Cell death and differentiation","url":"https://pubmed.ncbi.nlm.nih.gov/25857265","citation_count":20,"is_preprint":false},{"pmid":"14765136","id":"PMC_14765136","title":"RAIDD aggregation facilitates apoptotic death of PC12 cells and sympathetic neurons.","date":"2004","source":"Cell death and differentiation","url":"https://pubmed.ncbi.nlm.nih.gov/14765136","citation_count":18,"is_preprint":false},{"pmid":"11771742","id":"PMC_11771742","title":"Expression of apoptosis related proteins: RAIDD, ZIP kinase, Bim/BOD, p21, Bax, Bcl-2 and NF-kappaB in brains of patients with Down syndrome.","date":"2001","source":"Journal of neural transmission. Supplementum","url":"https://pubmed.ncbi.nlm.nih.gov/11771742","citation_count":16,"is_preprint":false},{"pmid":"19125251","id":"PMC_19125251","title":"RAIDD expression is impaired in multidrug resistant osteosarcoma cell lines.","date":"2009","source":"Cancer chemotherapy and pharmacology","url":"https://pubmed.ncbi.nlm.nih.gov/19125251","citation_count":14,"is_preprint":false},{"pmid":"24064063","id":"PMC_24064063","title":"PIDD mediates and stabilizes the interaction between RAIDD and caspase-2 for the PIDDosome assembly.","date":"2013","source":"BMB reports","url":"https://pubmed.ncbi.nlm.nih.gov/24064063","citation_count":14,"is_preprint":false},{"pmid":"17329820","id":"PMC_17329820","title":"Crystallization and preliminary X-ray crystallographic studies of the oligomeric death-domain complex between PIDD and RAIDD.","date":"2007","source":"Acta crystallographica. Section F, Structural biology and crystallization communications","url":"https://pubmed.ncbi.nlm.nih.gov/17329820","citation_count":14,"is_preprint":false},{"pmid":"20406701","id":"PMC_20406701","title":"Identification and analysis of dominant negative mutants of RAIDD and PIDD.","date":"2010","source":"Biochimica et biophysica acta","url":"https://pubmed.ncbi.nlm.nih.gov/20406701","citation_count":13,"is_preprint":false},{"pmid":"30914828","id":"PMC_30914828","title":"Phenotypic spectrum associated with a CRADD founder variant underlying frontotemporal predominant pachygyria in the Finnish population.","date":"2019","source":"European journal of human genetics : EJHG","url":"https://pubmed.ncbi.nlm.nih.gov/30914828","citation_count":13,"is_preprint":false},{"pmid":"22323537","id":"PMC_22323537","title":"Cutting edge: the \"death\" adaptor CRADD/RAIDD targets BCL10 and suppresses agonist-induced cytokine expression in T lymphocytes.","date":"2012","source":"Journal of immunology (Baltimore, Md. : 1950)","url":"https://pubmed.ncbi.nlm.nih.gov/22323537","citation_count":12,"is_preprint":false},{"pmid":"15947787","id":"PMC_15947787","title":"RAIDD is required for apoptosis of PC12 cells and sympathetic neurons induced by trophic factor withdrawal.","date":"2006","source":"Cell death and differentiation","url":"https://pubmed.ncbi.nlm.nih.gov/15947787","citation_count":12,"is_preprint":false},{"pmid":"25360218","id":"PMC_25360218","title":"Regulation of CRADD-caspase 2 cascade by histone deacetylase 1 in gastric cancer.","date":"2014","source":"American journal of translational research","url":"https://pubmed.ncbi.nlm.nih.gov/25360218","citation_count":9,"is_preprint":false},{"pmid":"33647455","id":"PMC_33647455","title":"CRADD and USP44 mutations in intellectual disability, mild lissencephaly, brain atrophy, developmental delay, strabismus, behavioural problems and skeletal anomalies.","date":"2021","source":"European journal of medical genetics","url":"https://pubmed.ncbi.nlm.nih.gov/33647455","citation_count":9,"is_preprint":false},{"pmid":"24958727","id":"PMC_24958727","title":"The adaptor CRADD/RAIDD controls activation of endothelial cells by proinflammatory stimuli.","date":"2014","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/24958727","citation_count":8,"is_preprint":false},{"pmid":"27502430","id":"PMC_27502430","title":"Rescuing neuronal cell death by RAIDD- and PIDD- derived peptides and its implications for therapeutic intervention in neurodegenerative diseases.","date":"2016","source":"Scientific reports","url":"https://pubmed.ncbi.nlm.nih.gov/27502430","citation_count":8,"is_preprint":false},{"pmid":"19582216","id":"PMC_19582216","title":"Purification, crystallization and preliminary x-ray crystallographic studies of RAIDD Death-Domain (DD).","date":"2009","source":"International journal of molecular sciences","url":"https://pubmed.ncbi.nlm.nih.gov/19582216","citation_count":8,"is_preprint":false},{"pmid":"12558660","id":"PMC_12558660","title":"Overexpression of Raidd cDNA inhibits differentiation of mouse preadipocytes.","date":"2003","source":"Cell proliferation","url":"https://pubmed.ncbi.nlm.nih.gov/12558660","citation_count":7,"is_preprint":false},{"pmid":"30281648","id":"PMC_30281648","title":"RAIDD mutations underlie the pathogenesis of thin lissencephaly (TLIS).","date":"2018","source":"PloS one","url":"https://pubmed.ncbi.nlm.nih.gov/30281648","citation_count":5,"is_preprint":false},{"pmid":"27606466","id":"PMC_27606466","title":"RAIDD Mediates TLR3 and IRF7 Driven Type I Interferon Production.","date":"2016","source":"Cellular physiology and biochemistry : international journal of experimental cellular physiology, biochemistry, and pharmacology","url":"https://pubmed.ncbi.nlm.nih.gov/27606466","citation_count":5,"is_preprint":false},{"pmid":"39233177","id":"PMC_39233177","title":"CRADD and cIAP1 antagonistically regulate caspase-9-mediated apoptosis in teleost.","date":"2024","source":"International journal of biological macromolecules","url":"https://pubmed.ncbi.nlm.nih.gov/39233177","citation_count":3,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":15553,"output_tokens":5149,"usd":0.061947,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":13410,"output_tokens":4140,"usd":0.085275,"stage2_stop_reason":"end_turn"},"total_usd":0.147222,"stage1_batch_id":"msgbatch_01ACAxJQabDsht39JXeWG22d","stage2_batch_id":"msgbatch_01QEU22A9U5sbPTgsMzTmvSf","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 1997,\n      \"finding\": \"RAIDD/CRADD is a bipartite adaptor molecule: its C-terminal death domain (DD) binds the DD of RIP (a serine/threonine kinase), and its N-terminal CARD (caspase recruitment domain, homologous to ICE/CED-3 prodomains) mediates homophilic binding to caspase-2 (ICH-1) and C. elegans CED-3, directly linking death proteases to signaling pathways.\",\n      \"method\": \"Yeast two-hybrid, co-immunoprecipitation, domain mapping with mutations equivalent to inactivating ced-3 mutations\",\n      \"journal\": \"Nature\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal binding assays with domain mutants, independently replicated in same year by separate lab (PMID:9044836)\",\n      \"pmids\": [\"8985253\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1997,\n      \"finding\": \"CRADD has an NH2-terminal caspase homology domain that interacts with caspase-2 and a COOH-terminal death domain that interacts with RIP, and CRADD is constitutively expressed in many tissues.\",\n      \"method\": \"Co-immunoprecipitation, domain deletion constructs, overexpression apoptosis assay\",\n      \"journal\": \"Cancer research\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — independent replication of RAIDD mechanism by separate lab using reciprocal co-IP and domain mapping\",\n      \"pmids\": [\"9044836\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1998,\n      \"finding\": \"NMR solution structure of the RAIDD CARD reveals six tightly packed helices in a topology homologous to the Fas death domain, with a basic patch and an acidic patch on opposite sides that mediate CARD/CARD interaction with ICH-1/caspase-2; mutagenesis of these patches disrupts the interaction.\",\n      \"method\": \"NMR structure determination, homology modeling, mutagenesis\",\n      \"journal\": \"Cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — high-resolution NMR structure combined with mutagenesis validating the interaction surface\",\n      \"pmids\": [\"9695946\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2000,\n      \"finding\": \"Endogenous RAIDD localizes predominantly to the cytoplasm and, to a lesser extent, the nucleus; co-expression with caspase-2 recruits a fraction of RAIDD to the nucleus and causes CARD-dependent colocalization at discrete subcellular structures. Overexpression of the RAIDD-CARD alone forms filamentous oligomeric structures similar to death effector filaments, partially colocalizing with FADD/FLICE DEFs, suggesting CARD-mediated higher-order complex formation is regulated by intramolecular folding.\",\n      \"method\": \"Subcellular fractionation, immunofluorescence/confocal microscopy, transfection of domain mutants\",\n      \"journal\": \"Cell death and differentiation\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — direct localization experiments with functional domain dissection, single lab, multiple imaging approaches\",\n      \"pmids\": [\"10713730\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2005,\n      \"finding\": \"PIDD-induced apoptosis and growth suppression in embryonic fibroblasts require the adaptor protein RAIDD; RAIDD-deficient MEFs are resistant to PIDD-induced cell death, which is associated with early activation of caspase-2 and later activation of caspases-3 and -7. Caspase-2 knockout MEFs are only partially resistant, indicating caspase-2 contributes but is not the sole effector downstream of RAIDD.\",\n      \"method\": \"Genetic knockout (RAIDD-/- and caspase-2-/- MEFs), caspase activity assays, cell death assays\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — clean genetic epistasis using knockout cells with defined apoptotic readouts and caspase activity measurements\",\n      \"pmids\": [\"16183742\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2000,\n      \"finding\": \"RAIDD is dispensable for Fas ligand-induced apoptosis in lymphoid cells; loss of RAIDD does not affect FasL-mediated cell death.\",\n      \"method\": \"Genetic studies in RAIDD-deficient cells, cell death assays\",\n      \"journal\": \"Journal of immunology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — negative finding from knockout/deficient cells, single study\",\n      \"pmids\": [\"10903735\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2006,\n      \"finding\": \"Crystal structure of the RAIDD death domain determined at 2.0 Å resolution, revealing structural features important for DD folding, dynamics, and PIDDosome assembly via DD:DD interaction with PIDD.\",\n      \"method\": \"X-ray crystallography at 2.0 Å resolution\",\n      \"journal\": \"Journal of molecular biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — high-resolution crystal structure, single lab but rigorous structural method\",\n      \"pmids\": [\"16434054\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2004,\n      \"finding\": \"RAIDD interacts with rat caspase-2 via CARD-CARD interaction in neuronal (PC12) cells; RAIDD overexpression induces caspase-2 CARD- and caspase-9-dependent apoptosis in PC12 cells and sympathetic neurons, correlating with formation of discrete perinuclear aggregates; full-length RAIDD is required for both death and aggregate formation.\",\n      \"method\": \"Co-immunoprecipitation, overexpression with domain mutants, cell death assays, fluorescence microscopy\",\n      \"journal\": \"Cell death and differentiation\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — reciprocal interaction assays combined with domain deletion and phenotypic readouts, single lab\",\n      \"pmids\": [\"14765136\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2006,\n      \"finding\": \"Endogenous RAIDD is required for trophic factor withdrawal-induced apoptosis of PC12 cells and sympathetic neurons; siRNA knockdown of RAIDD inhibits trophic deprivation-induced death but not DNA damage-induced (non-caspase-2-mediated) death, indicating RAIDD acts specifically through caspase-2 in this context.\",\n      \"method\": \"siRNA knockdown, dominant-negative CARD fragment expression, cell death assays\",\n      \"journal\": \"Cell death and differentiation\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — loss-of-function via siRNA with specific pathway controls, single lab\",\n      \"pmids\": [\"15947787\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2007,\n      \"finding\": \"The PIDD DD–RAIDD DD complex forms an oligomeric assembly of ~150 kDa in solution (as measured by gel filtration and MALS), mediated by homotypic DD:DD interactions; the complex was crystallized and diffracted to 3.2 Å.\",\n      \"method\": \"Recombinant protein purification, gel filtration, multi-angle light scattering (MALS), crystallography\",\n      \"journal\": \"Acta crystallographica Section F\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1 / Weak — biochemical reconstitution of complex with size determination, crystallography preliminary data, single lab\",\n      \"pmids\": [\"17329820\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"PIDDosome assembly is time-dependent and salt concentration-dependent; point mutations R147E in RAIDD and Y814A in PIDD exert dominant-negative effects on PIDDosome formation but cannot disrupt pre-formed PIDDosome complexes.\",\n      \"method\": \"Recombinant protein purification, biochemical assembly assays, site-directed mutagenesis\",\n      \"journal\": \"Biochimica et biophysica acta\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1 / Weak — in vitro reconstitution with mutagenesis, single lab\",\n      \"pmids\": [\"20406701\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"In ATLL cells, LBH589 (HDAC inhibitor) activates apoptosis via a RAIDD-initiated pathway; siRNA knockdown experiments showed RAIDD activation is the initiating event upstream of caspase-2 and caspase-9 in this context, and RIPK1 is also required.\",\n      \"method\": \"siRNA knockdown of RAIDD, PIDD, caspase-2, caspase-9, and RIPK1; caspase activity assays; DNA microarray\",\n      \"journal\": \"Leukemia\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — loss-of-function siRNA epistasis with caspase activity readouts, single lab\",\n      \"pmids\": [\"21242994\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"In neurons, caspase-2 activation and caspase-2-dependent neuronal death induced by NGF deprivation or Aβ treatment require RAIDD but not PIDD; RAIDD and caspase-2 form a complex in neurons treated with these stimuli, demonstrable by co-immunoprecipitation from PIDD-null neurons.\",\n      \"method\": \"Genetic knockout (RAIDD-/- and PIDD-/- neurons), active caspase-2 detection, co-immunoprecipitation, cell death assays\",\n      \"journal\": \"The Biochemical journal\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — clean genetic epistasis with two distinct knockouts, reciprocal Co-IP showing complex formation, multiple stimuli tested\",\n      \"pmids\": [\"22515271\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"CRADD interacts with BCL10 through its CARD domain and suppresses the BCL10-CARMA1 interaction; TCR agonist stimulation induces CRADD-BCL10 interaction coincident with reduced BCL10-CARMA1 complex formation; Cradd-deficient T cells and mice produce significantly higher levels of IFN-γ, IL-2, TNF-α, and IL-17 in response to TCR agonists.\",\n      \"method\": \"Co-immunoprecipitation, Cradd-/- primary cells and mice, cytokine measurement\",\n      \"journal\": \"Journal of immunology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — reciprocal Co-IP showing CARD-dependent BCL10 binding, genetic knockout with quantified cytokine output, single lab\",\n      \"pmids\": [\"22323537\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"PIDD DD mediates and stabilizes the interaction between RAIDD and caspase-2 during PIDDosome assembly: full-length RAIDD in a 'closed' conformation cannot interact with caspase-2 CARD alone; PIDD DD must first bind RAIDD DD to open RAIDD and allow subsequent recruitment of caspase-2 via CARD:CARD interaction.\",\n      \"method\": \"Recombinant protein purification, solubility/binding assays, biochemical reconstitution of the sequential assembly\",\n      \"journal\": \"BMB reports\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1 / Weak — in vitro reconstitution revealing ordered assembly mechanism, single lab\",\n      \"pmids\": [\"24064063\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"HDAC1 directly binds the CRADD promoter and downregulates CRADD expression; TSA (HDAC inhibitor) induces CRADD expression to activate caspase-2-dependent apoptosis; HDAC1 siRNA upregulates CRADD in gastric cancer cells.\",\n      \"method\": \"ChIP assay (HDAC1 binding to CRADD promoter), siRNA knockdown, caspase-2 activity assays, Western blot\",\n      \"journal\": \"American journal of translational research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — ChIP demonstrating direct promoter binding, functional siRNA rescue, single lab\",\n      \"pmids\": [\"25360218\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"CRADD-deficient murine endothelial cells show heightened BCL10-mediated IL-6 and MCP-1 expression and increased permeability in response to LPS and thrombin, with increased F-actin polymerization and disrupted adherens junctions; delivery of cell-penetrating CP-CRADD protein restores barrier function and suppresses cytokine induction, defining CRADD as an inducible suppressor of BCL10 in endothelial cells.\",\n      \"method\": \"Cradd-/- primary endothelial cells, permeability assays, F-actin staining, recombinant CP-CRADD protein delivery, cytokine measurement\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — genetic knockout with multiple phenotypic readouts (permeability, cytokines, cytoskeleton) and rescue with recombinant protein, single lab\",\n      \"pmids\": [\"24958727\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"The tumor-modulatory effects of Caspase-2 and Pidd1 in the Eμ-Myc lymphoma model do not require Raidd; Eμ-Myc/Raidd-/- mice show no protection from c-Myc-driven lymphomagenesis, uncoupling Raidd from Caspase-2's tumor suppressor function and Pidd1's tumor-promoting function.\",\n      \"method\": \"Eμ-Myc/Raidd-/- mouse model, tumor onset monitoring, genetic epistasis\",\n      \"journal\": \"Cell death and differentiation\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — clean in vivo genetic epistasis in mouse cancer model, single lab, negative result for Raidd's role\",\n      \"pmids\": [\"25857265\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"RAIDD interacts with IRF7 and its kinase IKKε by co-immunoprecipitation; RAIDD-deficient cells show dramatically reduced type I IFN activation by IKKε and IRF7; deletion of either the CARD or DD of RAIDD inhibits IKKε/IRF7-mediated IFN-4α activation, indicating both domains are required for this function.\",\n      \"method\": \"Immunoprecipitation, shRNA lentiviral knockdown, IFN-driven dual luciferase reporter assay, domain deletion constructs\",\n      \"journal\": \"Cellular physiology and biochemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP showing molecular interaction with IRF7/IKKε, loss-of-function with luciferase reporter and domain mutants, single lab\",\n      \"pmids\": [\"27606466\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"CRADD death domain mutations (G128R, F164C, R170C, R170H) found in thin lissencephaly patients do not disrupt interactions with caspase-2 or PIDD in co-immunoprecipitation assays, but still abolish CRADD's ability to activate caspase-2, resulting in reduced neuronal apoptosis in vitro; homozygous Cradd knockout mice display megalencephaly and seizures, establishing CRADD/caspase-2 signaling as required for normal cortical gyration.\",\n      \"method\": \"Co-immunoprecipitation of mutant CRADD with PIDD and caspase-2, caspase-2 activity assays, Cradd-/- mouse phenotyping\",\n      \"journal\": \"American journal of human genetics\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — multiple disease mutations tested biochemically with Co-IP and functional caspase assay, corroborated by in vivo knockout mouse phenotype\",\n      \"pmids\": [\"27773430\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"TAT-fused peptides containing wild-type helix 3 (H3) from RAIDD block PIDDosome formation in vitro and inhibit rotenone-induced caspase-2-dependent apoptosis in neuronal cells, demonstrating that the H3 region of RAIDD is critical for PIDDosome assembly.\",\n      \"method\": \"In vitro PIDDosome assembly assay, cell-penetrating peptide inhibition, caspase-2 activity assay in neuronal cells\",\n      \"journal\": \"Scientific reports\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1 / Weak — in vitro reconstitution blockade combined with cell-based functional assay, single lab\",\n      \"pmids\": [\"27502430\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"TLIS-associated RAIDD DD mutations (G128R, F164C, R170C, R170H) were analyzed biochemically; mutagenesis and binding assays revealed the molecular basis by which these mutations impair caspase-2 activation while leaving PIDD/caspase-2 interaction partially intact.\",\n      \"method\": \"Site-directed mutagenesis, recombinant protein expression, biochemical binding assays\",\n      \"journal\": \"PloS one\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1 / Weak — mutagenesis with biochemical assays, single lab, extends prior structural work\",\n      \"pmids\": [\"30281648\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"CRADD/RAIDD is a bipartite adaptor protein with an N-terminal CARD and a C-terminal death domain: the DD binds the DD of PIDD (and RIP/RIPK1), while the CARD mediates homophilic interaction with the prodomain of caspase-2, assembling the PIDDosome complex in which PIDD-DD binding to RAIDD-DD is required first to open RAIDD and allow caspase-2 CARD recruitment, leading to proximity-induced caspase-2 dimerization and activation that drives apoptosis in neurons and stress-induced contexts; beyond apoptosis, CRADD also suppresses inflammatory signaling by binding BCL10 through its CARD to inhibit the CARMA1/CARMA3 signalosome, and coordinates type I interferon production by scaffolding IKKε–IRF7 interactions through both its CARD and DD.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"CRADD (RAIDD) is a bipartite adaptor protein that links death proteases to upstream signaling through two homotypic interaction modules: a C-terminal death domain (DD) that binds the DD of RIP/RIPK1 and PIDD, and an N-terminal CARD that homophilically engages the prodomain of caspase-2 [#0, #1]. Structural work defined both modules \\u2014 the CARD as a six-helix bundle with opposing basic and acidic patches that constitute the caspase-2 interaction surface [#2], and the DD by crystallography as the unit driving PIDDosome assembly [#6]. CRADD nucleates the PIDDosome through an ordered, conformationally gated mechanism: PIDD-DD must first bind the RAIDD-DD to open the otherwise closed full-length adaptor, permitting subsequent CARD:CARD recruitment of caspase-2 and proximity-induced caspase activation [#14, #9, #10]. This adaptor function drives apoptosis in specific contexts, most prominently neuronal death following trophic factor withdrawal, NGF deprivation, or A\\u03b2 exposure, where RAIDD is required to assemble with and activate caspase-2 \\u2014 in neurons independently of PIDD [#8, #12, #4]. CRADD/caspase-2 signaling is required for normal cortical development: DD mutations (G128R, F164C, R170C, R170H) abolish caspase-2 activation while leaving PIDD/caspase-2 binding intact and cause thin/thick lissencephaly in patients, with Cradd-knockout mice showing megalencephaly and seizures [#19, #21]. Beyond apoptosis, CRADD restrains inflammatory signaling by binding BCL10 through its CARD to suppress the BCL10\\u2013CARMA1 signalosome, limiting cytokine output in T cells and endothelial barrier disruption [#13, #16], and it scaffolds IKK\\u03b5\\u2013IRF7 interactions through both its CARD and DD to support type I interferon production [#18]. CRADD is dispensable for Fas-mediated apoptosis and for the tumor-modulatory effects of caspase-2/PIDD1 in Myc-driven lymphoma, indicating its functions are pathway- and context-restricted [#5, #17].\",\n  \"teleology\": [\n    {\n      \"year\": 1997,\n      \"claim\": \"Established CRADD/RAIDD as a bipartite adaptor that physically bridges an upstream kinase to a death protease, answering how caspase-2 is connected to signaling complexes.\",\n      \"evidence\": \"Yeast two-hybrid, reciprocal co-immunoprecipitation, and domain mapping mapping the DD to RIP and the CARD to caspase-2/CED-3, independently replicated by a second lab the same year\",\n      \"pmids\": [\"8985253\", \"9044836\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not define the physiological stimulus or higher-order assembly\", \"RIP/RIPK1 functional role left uncharacterized\"]\n    },\n    {\n      \"year\": 1998,\n      \"claim\": \"Defined the structural basis of CARD-mediated caspase-2 recruitment, identifying the charged surface patches that constitute the interaction interface.\",\n      \"evidence\": \"NMR solution structure of the RAIDD CARD with homology modeling and interface mutagenesis disrupting the caspase-2 interaction\",\n      \"pmids\": [\"9695946\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Structure of full-length adaptor and how CARD accessibility is regulated not resolved\", \"No structure of the CARD:CARD complex itself\"]\n    },\n    {\n      \"year\": 2000,\n      \"claim\": \"Showed CRADD function is pathway-restricted by establishing it is dispensable for Fas-induced apoptosis, and that its CARD drives higher-order oligomeric assemblies under intramolecular control.\",\n      \"evidence\": \"Cell death assays in RAIDD-deficient lymphoid cells; subcellular fractionation and confocal imaging of domain mutants forming filamentous structures\",\n      \"pmids\": [\"10903735\", \"10713730\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Negative Fas result from a single study\", \"Functional significance of CARD filaments in endogenous setting unclear\"]\n    },\n    {\n      \"year\": 2004,\n      \"claim\": \"Connected CRADD to neuronal apoptosis, showing CARD-dependent caspase-2 recruitment drives death in neurons.\",\n      \"evidence\": \"Co-IP, domain mutants, cell death assays and microscopy in PC12 cells and sympathetic neurons showing full-length RAIDD is required for death and aggregate formation\",\n      \"pmids\": [\"14765136\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Relied on overexpression for the death phenotype\", \"Endogenous requirement not yet demonstrated\"]\n    },\n    {\n      \"year\": 2005,\n      \"claim\": \"Placed RAIDD genetically upstream in PIDD-induced death, establishing it as an obligate adaptor whose loss confers resistance.\",\n      \"evidence\": \"RAIDD-/- and caspase-2-/- MEFs with caspase activity and death assays showing RAIDD requirement and partial caspase-2 dependence\",\n      \"pmids\": [\"16183742\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Identity of caspase-2-independent effector downstream of RAIDD unknown\"]\n    },\n    {\n      \"year\": 2006,\n      \"claim\": \"Demonstrated the endogenous physiological requirement for RAIDD in trophic-deprivation neuronal death and its stimulus specificity, distinguishing caspase-2-dependent from DNA-damage death.\",\n      \"evidence\": \"siRNA knockdown and dominant-negative CARD fragment expression with pathway-specific death assays; DD crystal structure at 2.0 \\u00c5\",\n      \"pmids\": [\"15947787\", \"16434054\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Mechanism distinguishing trophic versus DNA-damage death routing not defined\"]\n    },\n    {\n      \"year\": 2010,\n      \"claim\": \"Reconstituted the PIDDosome in vitro and characterized its oligomeric stoichiometry and assembly determinants, defining DD:DD contacts as the assembly driver.\",\n      \"evidence\": \"Recombinant protein purification, gel filtration, MALS, and dominant-negative point mutants (RAIDD R147E, PIDD Y814A) in biochemical assembly assays\",\n      \"pmids\": [\"17329820\", \"20406701\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Did not capture caspase-2-incorporated complex\", \"In vitro assembly kinetics may not reflect cellular regulation\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Resolved the in vivo neuronal mechanism, showing RAIDD\\u2013caspase-2 complex assembly is required but PIDD is dispensable in neurons, and uncovered a non-apoptotic role suppressing BCL10\\u2013CARMA1 inflammatory signaling.\",\n      \"evidence\": \"RAIDD-/- and PIDD-/- neurons with active caspase-2 detection and co-IP; Cradd-/- T cells/mice with CARD-dependent BCL10 co-IP and cytokine measurement\",\n      \"pmids\": [\"22515271\", \"22323537\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"PIDD-independent neuronal scaffold for RAIDD not identified\", \"How a single CARD partitions between caspase-2 and BCL10 binding unclear\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Defined the ordered, conformationally gated assembly mechanism whereby PIDD-DD binding opens closed RAIDD to permit caspase-2 recruitment.\",\n      \"evidence\": \"Recombinant protein solubility/binding assays reconstituting sequential PIDDosome assembly\",\n      \"pmids\": [\"24064063\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Structural detail of the closed-to-open transition not visualized\", \"In vitro model not validated in cells\"]\n    },\n    {\n      \"year\": 2014,\n      \"claim\": \"Extended CRADD's anti-inflammatory BCL10-suppressing role to endothelial barrier control and established transcriptional regulation of CRADD by HDAC1.\",\n      \"evidence\": \"Cradd-/- endothelial cells with permeability, cytoskeletal and cytokine readouts plus CP-CRADD rescue; ChIP showing HDAC1 binding the CRADD promoter with siRNA functional rescue\",\n      \"pmids\": [\"24958727\", \"25360218\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single-lab studies\", \"Direct competition between CRADD and CARMA1 for BCL10 not structurally defined\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Established CRADD/caspase-2 signaling as required for normal cortical gyration and identified its role in type I interferon production.\",\n      \"evidence\": \"Co-IP of lissencephaly DD mutants with PIDD/caspase-2, caspase-2 activity assays and Cradd-/- mouse phenotyping; Co-IP and domain-deletion luciferase reporter assays mapping IKK\\u03b5/IRF7 scaffolding to both CARD and DD\",\n      \"pmids\": [\"27773430\", \"27606466\", \"27502430\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"How DD mutations abolish caspase-2 activation despite intact binding not mechanistically resolved\", \"IKK\\u03b5/IRF7 scaffolding mechanism single-lab\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Provided the biochemical basis by which lissencephaly DD mutations impair caspase-2 activation while sparing PIDD/caspase-2 binding.\",\n      \"evidence\": \"Site-directed mutagenesis and recombinant binding assays of TLIS-associated DD mutants\",\n      \"pmids\": [\"30281648\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Mechanism couples binding-competent assembly to activation failure but lacks a structural model of the activating step\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How CRADD partitions a single CARD between pro-apoptotic caspase-2 recruitment and anti-inflammatory BCL10 sequestration, and how DD mutations uncouple PIDDosome binding from caspase-2 activation, remain unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No structure of the activated CARD:caspase-2 or CARD:BCL10 complex\", \"Identity of the caspase-2-independent effector downstream of RAIDD unknown\", \"Mechanistic coupling of assembly to caspase activation undefined\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0060090\", \"supporting_discovery_ids\": [0, 1, 14]},\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [13, 16, 18]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005829\", \"supporting_discovery_ids\": [3]},\n      {\"term_id\": \"GO:0005634\", \"supporting_discovery_ids\": [3]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-5357801\", \"supporting_discovery_ids\": [4, 8, 12]},\n      {\"term_id\": \"R-HSA-168256\", \"supporting_discovery_ids\": [13, 16, 18]}\n    ],\n    \"complexes\": [\"PIDDosome\"],\n    \"partners\": [\"CASP2\", \"PIDD1\", \"RIPK1\", \"BCL10\", \"IRF7\", \"IKBKE\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":7,"faith_total":7,"faith_pct":100.0}}