{"gene":"MARCHF3","run_date":"2026-06-10T02:59:50","timeline":{"discoveries":[{"year":2006,"finding":"MARCH3 localizes to peripheral vesicles (endosomes) partially colocalizing with transferrin receptor, associates with syntaxin 6 and MARCH-II, and its PDZ-binding motif and RING finger are required for subcellular localization and inhibition of transferrin uptake; overexpression redistributes TGN46 and strongly inhibits transferrin uptake.","method":"Immunofluorescence, immunoprecipitation, mutational analysis, transferrin uptake assay in HeLa cells","journal":"Journal of biochemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — reciprocal Co-IP, mutagenesis, and functional assay in single lab with multiple orthogonal methods","pmids":["16428329"],"is_preprint":false},{"year":2015,"finding":"TLR4 activation (LPS) upregulates MARCH3 expression in monocytes, and MARCH3 mediates ubiquitination of FcγRIIb, leading to its downregulation; siRNA knockdown of MARCH3 prevents LPS-induced FcγRIIb decrease.","method":"siRNA knockdown, flow cytometry for FcγRIIb surface levels, ubiquitination assay, LPS stimulation of monocytes","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — siRNA knockdown with defined functional readout and ubiquitination assay, single lab","pmids":["26694610"],"is_preprint":false},{"year":2016,"finding":"MARCH3 silencing in endothelial cells protects the endothelial barrier, upregulates the tight junction gene occludin (OCLN), strengthens cell-cell contacts through accumulation of junctional proteins, and inactivates the FoxO1 transcription repressor.","method":"siRNA library screen, transcriptome analysis, siRNA knockdown, junctional protein localization assay","journal":"FEBS letters","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — siRNA knockdown with transcriptome and phenotypic readout, single lab, single study","pmids":["27616439"],"is_preprint":false},{"year":2018,"finding":"MARCH3 associates with IL-1RI and mediates its K48-linked polyubiquitination at K409, leading to lysosomal-dependent degradation and attenuation of IL-1β-triggered NF-κB signaling; IL-1β stimulation triggers dephosphorylation of MARCH3 by CDC25A, activating its E3 ligase activity.","method":"Co-immunoprecipitation, ubiquitination assay, site-directed mutagenesis (K409), MARCH3 KO mice, cytokine measurement, Listeria monocytogenes infection model","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal Co-IP, mutagenesis, KO mouse model with in vivo phenotype, multiple orthogonal methods in single study","pmids":["30442668"],"is_preprint":false},{"year":2021,"finding":"MARCH3 associates with IL-6Rα and its co-receptor gp130 and mediates their polyubiquitination (IL-6Rα at K401; gp130 at K849) following IL-6 stimulation, leading to their lysosomal translocation and degradation, thereby suppressing IL-6/STAT3 signaling and colitis-associated carcinogenesis.","method":"Co-immunoprecipitation, ubiquitination assay, site-directed mutagenesis, MARCH3 KO mice, DSS/AOM colitis and cancer models","journal":"Cellular & molecular immunology","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal Co-IP, mutagenesis of ubiquitination sites, KO mouse model with in vivo disease readout, multiple orthogonal methods","pmids":["34785732"],"is_preprint":false},{"year":2022,"finding":"MARCH3 associates with IL-3Rα and mediates its K48-linked polyubiquitination at K377, promoting its proteasomal degradation and negatively regulating IL-3-triggered signaling; MARCH3 deficiency aggravates inflammatory death in a sepsis (CLP) model.","method":"Co-immunoprecipitation, ubiquitination assay, site-directed mutagenesis (K377), MARCH3 KO mice, CLP sepsis model","journal":"Signal transduction and targeted therapy","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal Co-IP, mutagenesis, KO mouse in vivo model, multiple orthogonal methods in single study","pmids":["35075102"],"is_preprint":false},{"year":2022,"finding":"MARCH3 (and MARCH2) associate with IL-5Rα and mediate its K27-linked polyubiquitination at K383 (MARCH3) and K379 (MARCH2), leading to lysosomal degradation; March2/3 double KO markedly increases eosinophils and aggravates OVA-induced airway inflammation in mice.","method":"Co-immunoprecipitation, ubiquitination assay, site-directed mutagenesis, MARCH2/3 single and double KO mice, OVA allergy model","journal":"Cellular & molecular immunology","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal Co-IP, mutagenesis, double KO mouse model with in vivo disease phenotype, multiple orthogonal methods","pmids":["35982175"],"is_preprint":false},{"year":2023,"finding":"RNF173 (MARCHF3) associates with GRB2 and promotes its ubiquitination and degradation, thereby inhibiting RAF/MEK/ERK signaling and suppressing HCC cell proliferation, invasion, and migration.","method":"RNA sequencing, mass spectrometry, co-immunoprecipitation, in vitro and in vivo tumor models, RNF173 knockdown/overexpression","journal":"Cell communication and signaling : CCS","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP, mass spectrometry, functional in vitro and in vivo experiments, single lab","pmids":["37626338"],"is_preprint":false},{"year":2024,"finding":"MARCHF3 directly interacts with PARP1 via K48-linked ubiquitination leading to PARP1 degradation; this promotes double-strand DNA release and activates cGAS-STING signaling in dendritic cells, thereby stimulating DC-mediated antigen cross-presentation and CD8+ T-cell activation; ATF4 transcriptionally regulates MARCHF3 expression.","method":"Co-immunoprecipitation, ubiquitination assay, flow cytometry, subcutaneous and orthotopic HCC mouse models, MARCHF3 KO/OE","journal":"Journal for immunotherapy of cancer","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP, ubiquitination assay, in vivo mouse models, single lab","pmids":["39608977"],"is_preprint":false},{"year":2024,"finding":"MARCH3 mediates ubiquitination and degradation of GPX4 in hepatocytes under intermittent hypoxia conditions (promoted by IL-6 from macrophages), thereby regulating ferroptosis and lipid accumulation.","method":"Co-immunoprecipitation, western blotting, gene intervention (siRNA/overexpression), E3 ligase prediction (UbiBrowser), animal IH model","journal":"Advanced science (Weinheim, Baden-Wurttemberg, Germany)","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP, functional knockdown experiments, in vivo model, single lab","pmids":["39229924"],"is_preprint":false},{"year":2024,"finding":"MARCH3 mediates ubiquitination of NLRP3 in macrophages; miR-24-3p (from pancreatic acinar cell-derived exosomes) inhibits MARCH3 expression, thereby reducing NLRP3 ubiquitination and promoting macrophage M1 polarization and pyroptosis.","method":"miR-24-3p inhibitor experiments, MARCH3 gain/loss-of-function, NLRP3 ubiquitination assay in rat peritoneal macrophages","journal":"Pancreas","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single lab, indirect evidence through miRNA modulation, single method for ubiquitination","pmids":["38530976"],"is_preprint":false},{"year":2024,"finding":"MARCHF3 promotes ubiquitination of NLRP3 in SH-SY5Y cells; Aβ1-42 treatment decreases MARCHF3-NLRP3 interaction and NLRP3 ubiquitination, and Bushen Huoxue Acupuncture upregulates MARCHF3 to restore NLRP3 ubiquitination and inhibit caspase-1-dependent pyroptosis.","method":"Endogenous Co-IP with ubiquitin immunoblotting, western blot, in vivo AD mouse model (SAMP8), Aβ1-42 cell model","journal":"Metabolic brain disease","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single lab, single Co-IP method, indirect experimental context","pmids":["39556273"],"is_preprint":false},{"year":2025,"finding":"MARCH3 (and MARCH2) associate with TIM-1 and mediate its K48-linked polyubiquitination at K346 (MARCH3) and K338 (MARCH2), leading to proteasomal degradation; double KO of MARCH2/3 increases TIM-1 levels, enhances Zika virus infectivity and pathogenesis in mice in a TIM-1-dependent manner.","method":"Co-immunoprecipitation, ubiquitination assay, site-directed mutagenesis (K338/K346), MARCH2/3 single and double KO mice, TIM-1 KO reconstitution, ZIKV infection assay","journal":"Cellular & molecular immunology","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal Co-IP, mutagenesis of ubiquitination sites, double KO mouse with in vivo phenotype, TIM-1 KO rescue experiment confirming target specificity","pmids":["40817191"],"is_preprint":false},{"year":2025,"finding":"MARCHF3 interacts with SIGLEC1 and mediates its ubiquitination and degradation, thereby inactivating NF-κB signaling and protecting retinal cells from high glucose-induced oxidative stress and inflammation.","method":"Co-immunoprecipitation, cycloheximide chase assay, siRNA knockdown/overexpression, ARPE19 cell model","journal":"International ophthalmology","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single lab, single Co-IP method, no mutagenesis of ubiquitination sites","pmids":["40682693"],"is_preprint":false},{"year":2026,"finding":"MARCH3 interacts with hexokinase 2 (HK2) and promotes its ubiquitination and degradation, thereby suppressing glycolysis, tumor proliferation, migration, invasion, and enhancing paclitaxel sensitivity in nasopharyngeal carcinoma.","method":"Co-immunoprecipitation, GST pull-down, cycloheximide chase assay, ubiquitination assay, in vivo NPC mouse model","journal":"Journal of biochemical and molecular toxicology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP validated by orthogonal GST pull-down, ubiquitination assay, in vivo model, single lab","pmids":["42044316"],"is_preprint":false}],"current_model":"MARCHF3 is a plasma membrane- and endosome-associated RING-CH-type E3 ubiquitin ligase that attenuates inflammatory and growth factor receptor signaling by directly binding to and mediating K48-linked (or K27-linked) polyubiquitination of multiple transmembrane receptors (IL-1RI, IL-6Rα/gp130, IL-3Rα, IL-5Rα, TIM-1, FcγRIIb) and cytoplasmic substrates (GRB2, PARP1, GPX4, HK2, NLRP3, SIGLEC1), targeting them for lysosomal or proteasomal degradation; its ligase activity is regulated by CDC25A-mediated dephosphorylation, and it requires an intact RING finger and PDZ-binding motif for proper localization and function."},"narrative":{"mechanistic_narrative":"MARCHF3 (MARCH3) is a membrane-associated RING-CH-type E3 ubiquitin ligase that functions as a negative regulator of inflammatory and growth-factor receptor signaling by ubiquitinating transmembrane receptors and cytoplasmic substrates to drive their lysosomal or proteasomal degradation [PMID:30442668, PMID:34785732, PMID:35075102]. It localizes to endosomal vesicles, partially colocalizing with the transferrin receptor and associating with syntaxin 6 and MARCH-II, with both its RING finger and PDZ-binding motif required for correct localization and function [PMID:16428329]. A recurring mechanistic theme is receptor turnover: MARCH3 binds and ubiquitinates IL-1RI (K48-linked at K409) to attenuate IL-1β/NF-κB signaling, IL-6Rα/gp130 to suppress IL-6/STAT3 signaling and colitis-associated carcinogenesis, IL-3Rα (K48-linked at K377), and, redundantly with MARCH2, IL-5Rα (K27-linked) and the Zika virus entry factor TIM-1 (K48-linked), thereby controlling inflammatory cytokine responses, eosinophilia, and viral infectivity in vivo [PMID:30442668, PMID:34785732, PMID:35075102, PMID:35982175, PMID:40817191]. Its ligase activity is activated upon IL-1β stimulation through CDC25A-mediated dephosphorylation [PMID:30442668]. Beyond receptors, MARCH3 ubiquitinates cytoplasmic substrates including GRB2 to dampen RAF/MEK/ERK signaling, PARP1 to engage cGAS-STING-driven antigen cross-presentation, GPX4 in ferroptosis regulation, and HK2 to restrain glycolysis, linking it to tumor suppression in several contexts [PMID:37626338, PMID:39608977, PMID:39229924, PMID:42044316]. MARCHF3 expression is itself transcriptionally controlled, including by ATF4, and is induced by TLR4 activation [PMID:26694610, PMID:39608977].","teleology":[{"year":2006,"claim":"Established MARCH3 as an endosome-associated protein whose RING finger and PDZ-binding motif govern its localization and ability to regulate membrane trafficking, framing it as a membrane-acting RING-CH ligase.","evidence":"Immunofluorescence, reciprocal Co-IP, mutational analysis, and transferrin uptake assays in HeLa cells","pmids":["16428329"],"confidence":"Medium","gaps":["No direct demonstration of ubiquitin ligase catalytic activity in this study","Endogenous substrates not yet identified"]},{"year":2015,"claim":"Connected MARCH3 to innate immune regulation by showing TLR4/LPS induces it to ubiquitinate and downregulate the inhibitory Fc receptor FcγRIIb, indicating a role in controlling surface receptor levels in monocytes.","evidence":"siRNA knockdown, surface flow cytometry, and ubiquitination assay following LPS stimulation in monocytes","pmids":["26694610"],"confidence":"Medium","gaps":["Ubiquitin linkage type and acceptor lysine not defined","Direct vs indirect substrate engagement not established"]},{"year":2016,"claim":"Revealed a vascular function whereby MARCH3 controls endothelial barrier integrity and junctional protein abundance, linking its activity to FoxO1 regulation.","evidence":"siRNA library screen, transcriptome analysis, and junctional protein localization in endothelial cells","pmids":["27616439"],"confidence":"Medium","gaps":["Direct substrate mediating barrier effect not identified","Mechanistic link to ubiquitination not shown"]},{"year":2018,"claim":"Defined the canonical mechanism: MARCH3 directly binds IL-1RI and catalyzes K48-linked polyubiquitination at a specific lysine for lysosomal degradation, with activity switched on by CDC25A dephosphorylation, establishing it as an inducible brake on NF-κB inflammation in vivo.","evidence":"Reciprocal Co-IP, K409 mutagenesis, ubiquitination assays, KO mice, and Listeria infection model","pmids":["30442668"],"confidence":"High","gaps":["Phosphatase regulation generality across other substrates untested","Structural basis of substrate selection unknown"]},{"year":2021,"claim":"Extended the receptor-degradation paradigm to the IL-6 pathway, showing MARCH3 ubiquitinates both IL-6Rα and gp130 to suppress STAT3 signaling and colitis-associated cancer, generalizing its role as a cytokine receptor regulator.","evidence":"Reciprocal Co-IP, site-directed mutagenesis (K401/K849), KO mice, DSS/AOM colitis and cancer models","pmids":["34785732"],"confidence":"High","gaps":["Whether IL-6Rα and gp130 are ubiquitinated independently or as a complex not resolved"]},{"year":2022,"claim":"Showed MARCH3 negatively regulates IL-3 signaling via K48-linked, proteasomal degradation of IL-3Rα and that its loss worsens sepsis, broadening its substrate range to additional hematopoietic cytokine receptors.","evidence":"Reciprocal Co-IP, K377 mutagenesis, KO mice, CLP sepsis model","pmids":["35075102"],"confidence":"High","gaps":["Determinants distinguishing proteasomal vs lysosomal routing across substrates unclear"]},{"year":2022,"claim":"Demonstrated functional redundancy with MARCH2 in degrading IL-5Rα via atypical K27-linked ubiquitination, controlling eosinophil numbers and airway inflammation, indicating linkage-type flexibility.","evidence":"Reciprocal Co-IP, mutagenesis, MARCH2/3 single and double KO mice, OVA airway allergy model","pmids":["35982175"],"confidence":"High","gaps":["Mechanism dictating K27 vs K48 linkage choice unknown","Relative contributions of MARCH2 vs MARCH3 not quantified"]},{"year":2023,"claim":"Identified a cytoplasmic substrate, GRB2, establishing that MARCH3 dampens RAF/MEK/ERK growth signaling and suppresses hepatocellular carcinoma, extending its reach beyond membrane receptors.","evidence":"RNA-seq, mass spectrometry, Co-IP, knockdown/overexpression, in vitro and in vivo HCC tumor models","pmids":["37626338"],"confidence":"Medium","gaps":["Ubiquitin acceptor site on GRB2 not mapped","Linkage type not defined"]},{"year":2024,"claim":"Linked MARCH3 to nucleic-acid immune sensing by showing it degrades PARP1 to enable cGAS-STING activation and antigen cross-presentation, and that ATF4 transcriptionally drives its expression.","evidence":"Co-IP, ubiquitination assay, flow cytometry, subcutaneous/orthotopic HCC models with KO/OE","pmids":["39608977"],"confidence":"Medium","gaps":["Subcellular site of PARP1 ubiquitination not localized","How a membrane ligase accesses nuclear PARP1 unresolved"]},{"year":2024,"claim":"Implicated MARCH3 in ferroptosis and lipid metabolism through degradation of GPX4 under intermittent hypoxia, expanding its substrate set toward redox/metabolic regulators.","evidence":"Co-IP, western blot, siRNA/overexpression, E3 prediction, animal intermittent-hypoxia model","pmids":["39229924"],"confidence":"Medium","gaps":["Direct vs indirect targeting of GPX4 not confirmed by mutagenesis","Linkage type unspecified"]},{"year":2024,"claim":"Suggested MARCH3 restrains inflammasome activity by ubiquitinating NLRP3 in macrophages, with miRNA-mediated suppression promoting M1 polarization and pyroptosis.","evidence":"miR-24-3p modulation, MARCH3 gain/loss-of-function, NLRP3 ubiquitination assay in rat macrophages","pmids":["38530976"],"confidence":"Low","gaps":["Indirect evidence through miRNA modulation; single ubiquitination method","No acceptor-site mapping or reciprocal validation"]},{"year":2024,"claim":"Provided a second context for MARCH3-mediated NLRP3 ubiquitination, in a neuronal Alzheimer's model where amyloid-β reduces the interaction.","evidence":"Endogenous Co-IP with ubiquitin immunoblot, SAMP8 AD mouse and Aβ1-42 cell models","pmids":["39556273"],"confidence":"Low","gaps":["Single Co-IP without reciprocal validation","Direct catalytic activity on NLRP3 not demonstrated"]},{"year":2025,"claim":"Established MARCH3 (with MARCH2) as an antiviral restriction factor by degrading the viral entry receptor TIM-1 via K48 linkage, limiting Zika virus infectivity in a TIM-1-dependent manner in vivo.","evidence":"Reciprocal Co-IP, K346/K338 mutagenesis, MARCH2/3 KO mice, TIM-1 KO reconstitution, ZIKV infection","pmids":["40817191"],"confidence":"High","gaps":["Breadth of TIM-1-dependent viruses restricted not defined","Relative MARCH2/MARCH3 contribution not dissected"]},{"year":2025,"claim":"Proposed MARCH3 degrades SIGLEC1 to inactivate NF-κB and protect retinal cells from hyperglycemic stress, adding another candidate substrate.","evidence":"Co-IP, cycloheximide chase, siRNA/overexpression in ARPE19 cells","pmids":["40682693"],"confidence":"Low","gaps":["No mutagenesis of ubiquitination sites","Single-lab, single-method interaction evidence"]},{"year":2026,"claim":"Showed MARCH3 targets the glycolytic enzyme HK2 for degradation, suppressing glycolysis and tumor growth and enhancing chemosensitivity in nasopharyngeal carcinoma, reinforcing a metabolic/tumor-suppressive role.","evidence":"Co-IP, GST pull-down, cycloheximide chase, ubiquitination assay, in vivo NPC model","pmids":["42044316"],"confidence":"Medium","gaps":["Acceptor lysine and linkage type on HK2 not mapped"]},{"year":null,"claim":"It remains unresolved what governs MARCH3's substrate selectivity and its choice of ubiquitin linkage type (K48 vs K27) and degradation route (lysosomal vs proteasomal) across its diverse membrane and cytoplasmic targets.","evidence":"Not addressed by current timeline","pmids":[],"confidence":"Low","gaps":["No structural model of substrate recognition","Mechanism of linkage-type selection unknown","How a membrane ligase engages cytoplasmic/nuclear substrates like PARP1 unclear"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0016740","term_label":"transferase activity","supporting_discovery_ids":[3,4,5,6,12]},{"term_id":"GO:0140096","term_label":"catalytic activity, acting on a protein","supporting_discovery_ids":[3,4,5,6,12]},{"term_id":"GO:0016874","term_label":"ligase activity","supporting_discovery_ids":[3,5,12]}],"localization":[{"term_id":"GO:0005768","term_label":"endosome","supporting_discovery_ids":[0]},{"term_id":"GO:0031410","term_label":"cytoplasmic vesicle","supporting_discovery_ids":[0]},{"term_id":"GO:0005886","term_label":"plasma membrane","supporting_discovery_ids":[3,12]}],"pathway":[{"term_id":"R-HSA-168256","term_label":"Immune System","supporting_discovery_ids":[3,4,5,6,12]},{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[3,4,7]},{"term_id":"R-HSA-392499","term_label":"Metabolism of proteins","supporting_discovery_ids":[3,4,5,12]}],"complexes":[],"partners":["IL1R1","IL6R","IL6ST","IL3RA","IL5RA","HAVCR1","GRB2","STX6"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q86UD3","full_name":"E3 ubiquitin-protein ligase MARCHF3","aliases":["Membrane-associated RING finger protein 3","Membrane-associated RING-CH protein III","MARCH-III","RING finger protein 173","RING-type E3 ubiquitin transferase MARCHF3"],"length_aa":253,"mass_kda":28.5,"function":"E3 ubiquitin-protein ligase which may be involved in endosomal trafficking. E3 ubiquitin ligases accept ubiquitin from an E2 ubiquitin-conjugating enzyme in the form of a thioester and then directly transfer the ubiquitin to targeted substrates","subcellular_location":"Cytoplasmic vesicle membrane; Early endosome membrane","url":"https://www.uniprot.org/uniprotkb/Q86UD3/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/MARCHF3","classification":"Not Classified","n_dependent_lines":1,"n_total_lines":1090,"dependency_fraction":0.0009174311926605505},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/MARCHF3","total_profiled":1310},"omim":[{"mim_id":"613333","title":"MEMBRANE-ASSOCIATED RING-CH FINGER PROTEIN 3; MARCHF3","url":"https://www.omim.org/entry/613333"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Supported","locations":[{"location":"Vesicles","reliability":"Supported"}],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in many","driving_tissues":[],"url":"https://www.proteinatlas.org/search/MARCHF3"},"hgnc":{"alias_symbol":["MGC48332","MARCH-III","RNF173"],"prev_symbol":["MARCH3"]},"alphafold":{"accession":"Q86UD3","domains":[{"cath_id":"3.30.40.10","chopping":"70-120","consensus_level":"medium","plddt":89.7441,"start":70,"end":120},{"cath_id":"1.10.287","chopping":"130-218","consensus_level":"high","plddt":85.362,"start":130,"end":218}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q86UD3","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q86UD3-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q86UD3-F1-predicted_aligned_error_v6.png","plddt_mean":70.44},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=MARCHF3","jax_strain_url":"https://www.jax.org/strain/search?query=MARCHF3"},"sequence":{"accession":"Q86UD3","fasta_url":"https://rest.uniprot.org/uniprotkb/Q86UD3.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q86UD3/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q86UD3"}},"corpus_meta":[{"pmid":"30442668","id":"PMC_30442668","title":"MARCH3 attenuates IL-1β-triggered inflammation by mediating K48-linked polyubiquitination and degradation of IL-1RI.","date":"2018","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/30442668","citation_count":47,"is_preprint":false},{"pmid":"16428329","id":"PMC_16428329","title":"MARCH-III Is a novel component of endosomes with properties similar to those of MARCH-II.","date":"2006","source":"Journal of biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/16428329","citation_count":45,"is_preprint":false},{"pmid":"39229924","id":"PMC_39229924","title":"IL6 Derived from Macrophages under Intermittent Hypoxia Exacerbates NAFLD by Promoting Ferroptosis via MARCH3-Led Ubiquitylation of GPX4.","date":"2024","source":"Advanced science (Weinheim, Baden-Wurttemberg, Germany)","url":"https://pubmed.ncbi.nlm.nih.gov/39229924","citation_count":35,"is_preprint":false},{"pmid":"34785732","id":"PMC_34785732","title":"The membrane-associated E3 ubiquitin ligase MARCH3 downregulates the IL-6 receptor and suppresses colitis-associated carcinogenesis.","date":"2021","source":"Cellular & molecular immunology","url":"https://pubmed.ncbi.nlm.nih.gov/34785732","citation_count":31,"is_preprint":false},{"pmid":"35982175","id":"PMC_35982175","title":"The membrane-associated ubiquitin ligases MARCH2 and MARCH3 target IL-5 receptor alpha to negatively regulate eosinophilic airway inflammation.","date":"2022","source":"Cellular & molecular immunology","url":"https://pubmed.ncbi.nlm.nih.gov/35982175","citation_count":27,"is_preprint":false},{"pmid":"35075102","id":"PMC_35075102","title":"MARCH3 negatively regulates IL-3-triggered inflammatory response by mediating K48-linked polyubiquitination and degradation of IL-3Rα.","date":"2022","source":"Signal transduction and targeted therapy","url":"https://pubmed.ncbi.nlm.nih.gov/35075102","citation_count":27,"is_preprint":false},{"pmid":"37626338","id":"PMC_37626338","title":"RNF173 suppresses RAF/MEK/ERK signaling to regulate invasion and metastasis via GRB2 ubiquitination in Hepatocellular Carcinoma.","date":"2023","source":"Cell communication and signaling : CCS","url":"https://pubmed.ncbi.nlm.nih.gov/37626338","citation_count":23,"is_preprint":false},{"pmid":"27616439","id":"PMC_27616439","title":"The E3 ubiquitin ligase MARCH3 controls the endothelial barrier.","date":"2016","source":"FEBS letters","url":"https://pubmed.ncbi.nlm.nih.gov/27616439","citation_count":20,"is_preprint":false},{"pmid":"26694610","id":"PMC_26694610","title":"Toll-like Receptor 4 Ligands Down-regulate Fcγ Receptor IIb (FcγRIIb) via MARCH3 Protein-mediated Ubiquitination.","date":"2015","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/26694610","citation_count":19,"is_preprint":false},{"pmid":"39608977","id":"PMC_39608977","title":"Degradation of PARP1 by MARCHF3 in tumor cells triggers cCAS-STING activation in dendritic cells to regulate antitumor immunity in hepatocellular carcinoma.","date":"2024","source":"Journal for immunotherapy of cancer","url":"https://pubmed.ncbi.nlm.nih.gov/39608977","citation_count":15,"is_preprint":false},{"pmid":"38530976","id":"PMC_38530976","title":"Exosomes Derived From Cerulein-Stimulated Pancreatic Acinar Cells Mediate Peritoneal Macrophage M1 Polarization and Pyroptosis via an miR-24-3p/MARCH3/NLRP3 Axis in Acute Pancreatitis.","date":"2024","source":"Pancreas","url":"https://pubmed.ncbi.nlm.nih.gov/38530976","citation_count":8,"is_preprint":false},{"pmid":"40817191","id":"PMC_40817191","title":"The membrane-associated ubiquitin ligases MARCH2 and MARCH3 target TIM-1 to limit Zika virus infection.","date":"2025","source":"Cellular & molecular immunology","url":"https://pubmed.ncbi.nlm.nih.gov/40817191","citation_count":6,"is_preprint":false},{"pmid":"39556273","id":"PMC_39556273","title":"Bushen Huoxue acupuncture ameliorates Alzheimer's disease by upregulating MARCHF3 to induce NLRP3 ubiquitination and inhibit caspase-1-dependent pyroptosis.","date":"2024","source":"Metabolic brain disease","url":"https://pubmed.ncbi.nlm.nih.gov/39556273","citation_count":6,"is_preprint":false},{"pmid":"40682693","id":"PMC_40682693","title":"SIGLEC1 ubiquitination and degradation induced by MARCHF3 protects ARPE19 retinal cells from high glucose-induced oxidative stress, inflammation, and apoptosis.","date":"2025","source":"International ophthalmology","url":"https://pubmed.ncbi.nlm.nih.gov/40682693","citation_count":1,"is_preprint":false},{"pmid":"42044316","id":"PMC_42044316","title":"MARCH3 Inhibits Tumorigenesis and Enhances Paclitaxel Sensitivity in Nasopharyngeal Carcinoma by Ubiquitinating Hexokinase 2.","date":"2026","source":"Journal of biochemical and molecular toxicology","url":"https://pubmed.ncbi.nlm.nih.gov/42044316","citation_count":0,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":10097,"output_tokens":3698,"usd":0.042881,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":11373,"output_tokens":4880,"usd":0.089432,"stage2_stop_reason":"end_turn"},"total_usd":0.132313,"stage1_batch_id":"msgbatch_01BbTCMyrRPyhtEq6b1MdwCN","stage2_batch_id":"msgbatch_011dEed5bbxYvTAaQWKJevxu","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2006,\n      \"finding\": \"MARCH3 localizes to peripheral vesicles (endosomes) partially colocalizing with transferrin receptor, associates with syntaxin 6 and MARCH-II, and its PDZ-binding motif and RING finger are required for subcellular localization and inhibition of transferrin uptake; overexpression redistributes TGN46 and strongly inhibits transferrin uptake.\",\n      \"method\": \"Immunofluorescence, immunoprecipitation, mutational analysis, transferrin uptake assay in HeLa cells\",\n      \"journal\": \"Journal of biochemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — reciprocal Co-IP, mutagenesis, and functional assay in single lab with multiple orthogonal methods\",\n      \"pmids\": [\"16428329\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"TLR4 activation (LPS) upregulates MARCH3 expression in monocytes, and MARCH3 mediates ubiquitination of FcγRIIb, leading to its downregulation; siRNA knockdown of MARCH3 prevents LPS-induced FcγRIIb decrease.\",\n      \"method\": \"siRNA knockdown, flow cytometry for FcγRIIb surface levels, ubiquitination assay, LPS stimulation of monocytes\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — siRNA knockdown with defined functional readout and ubiquitination assay, single lab\",\n      \"pmids\": [\"26694610\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"MARCH3 silencing in endothelial cells protects the endothelial barrier, upregulates the tight junction gene occludin (OCLN), strengthens cell-cell contacts through accumulation of junctional proteins, and inactivates the FoxO1 transcription repressor.\",\n      \"method\": \"siRNA library screen, transcriptome analysis, siRNA knockdown, junctional protein localization assay\",\n      \"journal\": \"FEBS letters\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — siRNA knockdown with transcriptome and phenotypic readout, single lab, single study\",\n      \"pmids\": [\"27616439\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"MARCH3 associates with IL-1RI and mediates its K48-linked polyubiquitination at K409, leading to lysosomal-dependent degradation and attenuation of IL-1β-triggered NF-κB signaling; IL-1β stimulation triggers dephosphorylation of MARCH3 by CDC25A, activating its E3 ligase activity.\",\n      \"method\": \"Co-immunoprecipitation, ubiquitination assay, site-directed mutagenesis (K409), MARCH3 KO mice, cytokine measurement, Listeria monocytogenes infection model\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal Co-IP, mutagenesis, KO mouse model with in vivo phenotype, multiple orthogonal methods in single study\",\n      \"pmids\": [\"30442668\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"MARCH3 associates with IL-6Rα and its co-receptor gp130 and mediates their polyubiquitination (IL-6Rα at K401; gp130 at K849) following IL-6 stimulation, leading to their lysosomal translocation and degradation, thereby suppressing IL-6/STAT3 signaling and colitis-associated carcinogenesis.\",\n      \"method\": \"Co-immunoprecipitation, ubiquitination assay, site-directed mutagenesis, MARCH3 KO mice, DSS/AOM colitis and cancer models\",\n      \"journal\": \"Cellular & molecular immunology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal Co-IP, mutagenesis of ubiquitination sites, KO mouse model with in vivo disease readout, multiple orthogonal methods\",\n      \"pmids\": [\"34785732\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"MARCH3 associates with IL-3Rα and mediates its K48-linked polyubiquitination at K377, promoting its proteasomal degradation and negatively regulating IL-3-triggered signaling; MARCH3 deficiency aggravates inflammatory death in a sepsis (CLP) model.\",\n      \"method\": \"Co-immunoprecipitation, ubiquitination assay, site-directed mutagenesis (K377), MARCH3 KO mice, CLP sepsis model\",\n      \"journal\": \"Signal transduction and targeted therapy\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal Co-IP, mutagenesis, KO mouse in vivo model, multiple orthogonal methods in single study\",\n      \"pmids\": [\"35075102\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"MARCH3 (and MARCH2) associate with IL-5Rα and mediate its K27-linked polyubiquitination at K383 (MARCH3) and K379 (MARCH2), leading to lysosomal degradation; March2/3 double KO markedly increases eosinophils and aggravates OVA-induced airway inflammation in mice.\",\n      \"method\": \"Co-immunoprecipitation, ubiquitination assay, site-directed mutagenesis, MARCH2/3 single and double KO mice, OVA allergy model\",\n      \"journal\": \"Cellular & molecular immunology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal Co-IP, mutagenesis, double KO mouse model with in vivo disease phenotype, multiple orthogonal methods\",\n      \"pmids\": [\"35982175\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"RNF173 (MARCHF3) associates with GRB2 and promotes its ubiquitination and degradation, thereby inhibiting RAF/MEK/ERK signaling and suppressing HCC cell proliferation, invasion, and migration.\",\n      \"method\": \"RNA sequencing, mass spectrometry, co-immunoprecipitation, in vitro and in vivo tumor models, RNF173 knockdown/overexpression\",\n      \"journal\": \"Cell communication and signaling : CCS\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP, mass spectrometry, functional in vitro and in vivo experiments, single lab\",\n      \"pmids\": [\"37626338\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"MARCHF3 directly interacts with PARP1 via K48-linked ubiquitination leading to PARP1 degradation; this promotes double-strand DNA release and activates cGAS-STING signaling in dendritic cells, thereby stimulating DC-mediated antigen cross-presentation and CD8+ T-cell activation; ATF4 transcriptionally regulates MARCHF3 expression.\",\n      \"method\": \"Co-immunoprecipitation, ubiquitination assay, flow cytometry, subcutaneous and orthotopic HCC mouse models, MARCHF3 KO/OE\",\n      \"journal\": \"Journal for immunotherapy of cancer\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP, ubiquitination assay, in vivo mouse models, single lab\",\n      \"pmids\": [\"39608977\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"MARCH3 mediates ubiquitination and degradation of GPX4 in hepatocytes under intermittent hypoxia conditions (promoted by IL-6 from macrophages), thereby regulating ferroptosis and lipid accumulation.\",\n      \"method\": \"Co-immunoprecipitation, western blotting, gene intervention (siRNA/overexpression), E3 ligase prediction (UbiBrowser), animal IH model\",\n      \"journal\": \"Advanced science (Weinheim, Baden-Wurttemberg, Germany)\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP, functional knockdown experiments, in vivo model, single lab\",\n      \"pmids\": [\"39229924\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"MARCH3 mediates ubiquitination of NLRP3 in macrophages; miR-24-3p (from pancreatic acinar cell-derived exosomes) inhibits MARCH3 expression, thereby reducing NLRP3 ubiquitination and promoting macrophage M1 polarization and pyroptosis.\",\n      \"method\": \"miR-24-3p inhibitor experiments, MARCH3 gain/loss-of-function, NLRP3 ubiquitination assay in rat peritoneal macrophages\",\n      \"journal\": \"Pancreas\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single lab, indirect evidence through miRNA modulation, single method for ubiquitination\",\n      \"pmids\": [\"38530976\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"MARCHF3 promotes ubiquitination of NLRP3 in SH-SY5Y cells; Aβ1-42 treatment decreases MARCHF3-NLRP3 interaction and NLRP3 ubiquitination, and Bushen Huoxue Acupuncture upregulates MARCHF3 to restore NLRP3 ubiquitination and inhibit caspase-1-dependent pyroptosis.\",\n      \"method\": \"Endogenous Co-IP with ubiquitin immunoblotting, western blot, in vivo AD mouse model (SAMP8), Aβ1-42 cell model\",\n      \"journal\": \"Metabolic brain disease\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single lab, single Co-IP method, indirect experimental context\",\n      \"pmids\": [\"39556273\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"MARCH3 (and MARCH2) associate with TIM-1 and mediate its K48-linked polyubiquitination at K346 (MARCH3) and K338 (MARCH2), leading to proteasomal degradation; double KO of MARCH2/3 increases TIM-1 levels, enhances Zika virus infectivity and pathogenesis in mice in a TIM-1-dependent manner.\",\n      \"method\": \"Co-immunoprecipitation, ubiquitination assay, site-directed mutagenesis (K338/K346), MARCH2/3 single and double KO mice, TIM-1 KO reconstitution, ZIKV infection assay\",\n      \"journal\": \"Cellular & molecular immunology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal Co-IP, mutagenesis of ubiquitination sites, double KO mouse with in vivo phenotype, TIM-1 KO rescue experiment confirming target specificity\",\n      \"pmids\": [\"40817191\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"MARCHF3 interacts with SIGLEC1 and mediates its ubiquitination and degradation, thereby inactivating NF-κB signaling and protecting retinal cells from high glucose-induced oxidative stress and inflammation.\",\n      \"method\": \"Co-immunoprecipitation, cycloheximide chase assay, siRNA knockdown/overexpression, ARPE19 cell model\",\n      \"journal\": \"International ophthalmology\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single lab, single Co-IP method, no mutagenesis of ubiquitination sites\",\n      \"pmids\": [\"40682693\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"MARCH3 interacts with hexokinase 2 (HK2) and promotes its ubiquitination and degradation, thereby suppressing glycolysis, tumor proliferation, migration, invasion, and enhancing paclitaxel sensitivity in nasopharyngeal carcinoma.\",\n      \"method\": \"Co-immunoprecipitation, GST pull-down, cycloheximide chase assay, ubiquitination assay, in vivo NPC mouse model\",\n      \"journal\": \"Journal of biochemical and molecular toxicology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP validated by orthogonal GST pull-down, ubiquitination assay, in vivo model, single lab\",\n      \"pmids\": [\"42044316\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"MARCHF3 is a plasma membrane- and endosome-associated RING-CH-type E3 ubiquitin ligase that attenuates inflammatory and growth factor receptor signaling by directly binding to and mediating K48-linked (or K27-linked) polyubiquitination of multiple transmembrane receptors (IL-1RI, IL-6Rα/gp130, IL-3Rα, IL-5Rα, TIM-1, FcγRIIb) and cytoplasmic substrates (GRB2, PARP1, GPX4, HK2, NLRP3, SIGLEC1), targeting them for lysosomal or proteasomal degradation; its ligase activity is regulated by CDC25A-mediated dephosphorylation, and it requires an intact RING finger and PDZ-binding motif for proper localization and function.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"MARCHF3 (MARCH3) is a membrane-associated RING-CH-type E3 ubiquitin ligase that functions as a negative regulator of inflammatory and growth-factor receptor signaling by ubiquitinating transmembrane receptors and cytoplasmic substrates to drive their lysosomal or proteasomal degradation [#3, #4, #5]. It localizes to endosomal vesicles, partially colocalizing with the transferrin receptor and associating with syntaxin 6 and MARCH-II, with both its RING finger and PDZ-binding motif required for correct localization and function [#0]. A recurring mechanistic theme is receptor turnover: MARCH3 binds and ubiquitinates IL-1RI (K48-linked at K409) to attenuate IL-1\\u03b2/NF-\\u03baB signaling, IL-6R\\u03b1/gp130 to suppress IL-6/STAT3 signaling and colitis-associated carcinogenesis, IL-3R\\u03b1 (K48-linked at K377), and, redundantly with MARCH2, IL-5R\\u03b1 (K27-linked) and the Zika virus entry factor TIM-1 (K48-linked), thereby controlling inflammatory cytokine responses, eosinophilia, and viral infectivity in vivo [#3, #4, #5, #6, #12]. Its ligase activity is activated upon IL-1\\u03b2 stimulation through CDC25A-mediated dephosphorylation [#3]. Beyond receptors, MARCH3 ubiquitinates cytoplasmic substrates including GRB2 to dampen RAF/MEK/ERK signaling, PARP1 to engage cGAS-STING-driven antigen cross-presentation, GPX4 in ferroptosis regulation, and HK2 to restrain glycolysis, linking it to tumor suppression in several contexts [#7, #8, #9, #14]. MARCHF3 expression is itself transcriptionally controlled, including by ATF4, and is induced by TLR4 activation [#1, #8].\"\n,\n  \"teleology\": [\n    {\n      \"year\": 2006,\n      \"claim\": \"Established MARCH3 as an endosome-associated protein whose RING finger and PDZ-binding motif govern its localization and ability to regulate membrane trafficking, framing it as a membrane-acting RING-CH ligase.\",\n      \"evidence\": \"Immunofluorescence, reciprocal Co-IP, mutational analysis, and transferrin uptake assays in HeLa cells\",\n      \"pmids\": [\"16428329\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No direct demonstration of ubiquitin ligase catalytic activity in this study\", \"Endogenous substrates not yet identified\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"Connected MARCH3 to innate immune regulation by showing TLR4/LPS induces it to ubiquitinate and downregulate the inhibitory Fc receptor Fc\\u03b3RIIb, indicating a role in controlling surface receptor levels in monocytes.\",\n      \"evidence\": \"siRNA knockdown, surface flow cytometry, and ubiquitination assay following LPS stimulation in monocytes\",\n      \"pmids\": [\"26694610\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Ubiquitin linkage type and acceptor lysine not defined\", \"Direct vs indirect substrate engagement not established\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Revealed a vascular function whereby MARCH3 controls endothelial barrier integrity and junctional protein abundance, linking its activity to FoxO1 regulation.\",\n      \"evidence\": \"siRNA library screen, transcriptome analysis, and junctional protein localization in endothelial cells\",\n      \"pmids\": [\"27616439\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct substrate mediating barrier effect not identified\", \"Mechanistic link to ubiquitination not shown\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Defined the canonical mechanism: MARCH3 directly binds IL-1RI and catalyzes K48-linked polyubiquitination at a specific lysine for lysosomal degradation, with activity switched on by CDC25A dephosphorylation, establishing it as an inducible brake on NF-\\u03baB inflammation in vivo.\",\n      \"evidence\": \"Reciprocal Co-IP, K409 mutagenesis, ubiquitination assays, KO mice, and Listeria infection model\",\n      \"pmids\": [\"30442668\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Phosphatase regulation generality across other substrates untested\", \"Structural basis of substrate selection unknown\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Extended the receptor-degradation paradigm to the IL-6 pathway, showing MARCH3 ubiquitinates both IL-6R\\u03b1 and gp130 to suppress STAT3 signaling and colitis-associated cancer, generalizing its role as a cytokine receptor regulator.\",\n      \"evidence\": \"Reciprocal Co-IP, site-directed mutagenesis (K401/K849), KO mice, DSS/AOM colitis and cancer models\",\n      \"pmids\": [\"34785732\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether IL-6R\\u03b1 and gp130 are ubiquitinated independently or as a complex not resolved\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Showed MARCH3 negatively regulates IL-3 signaling via K48-linked, proteasomal degradation of IL-3R\\u03b1 and that its loss worsens sepsis, broadening its substrate range to additional hematopoietic cytokine receptors.\",\n      \"evidence\": \"Reciprocal Co-IP, K377 mutagenesis, KO mice, CLP sepsis model\",\n      \"pmids\": [\"35075102\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Determinants distinguishing proteasomal vs lysosomal routing across substrates unclear\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Demonstrated functional redundancy with MARCH2 in degrading IL-5R\\u03b1 via atypical K27-linked ubiquitination, controlling eosinophil numbers and airway inflammation, indicating linkage-type flexibility.\",\n      \"evidence\": \"Reciprocal Co-IP, mutagenesis, MARCH2/3 single and double KO mice, OVA airway allergy model\",\n      \"pmids\": [\"35982175\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Mechanism dictating K27 vs K48 linkage choice unknown\", \"Relative contributions of MARCH2 vs MARCH3 not quantified\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Identified a cytoplasmic substrate, GRB2, establishing that MARCH3 dampens RAF/MEK/ERK growth signaling and suppresses hepatocellular carcinoma, extending its reach beyond membrane receptors.\",\n      \"evidence\": \"RNA-seq, mass spectrometry, Co-IP, knockdown/overexpression, in vitro and in vivo HCC tumor models\",\n      \"pmids\": [\"37626338\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Ubiquitin acceptor site on GRB2 not mapped\", \"Linkage type not defined\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Linked MARCH3 to nucleic-acid immune sensing by showing it degrades PARP1 to enable cGAS-STING activation and antigen cross-presentation, and that ATF4 transcriptionally drives its expression.\",\n      \"evidence\": \"Co-IP, ubiquitination assay, flow cytometry, subcutaneous/orthotopic HCC models with KO/OE\",\n      \"pmids\": [\"39608977\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Subcellular site of PARP1 ubiquitination not localized\", \"How a membrane ligase accesses nuclear PARP1 unresolved\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Implicated MARCH3 in ferroptosis and lipid metabolism through degradation of GPX4 under intermittent hypoxia, expanding its substrate set toward redox/metabolic regulators.\",\n      \"evidence\": \"Co-IP, western blot, siRNA/overexpression, E3 prediction, animal intermittent-hypoxia model\",\n      \"pmids\": [\"39229924\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct vs indirect targeting of GPX4 not confirmed by mutagenesis\", \"Linkage type unspecified\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Suggested MARCH3 restrains inflammasome activity by ubiquitinating NLRP3 in macrophages, with miRNA-mediated suppression promoting M1 polarization and pyroptosis.\",\n      \"evidence\": \"miR-24-3p modulation, MARCH3 gain/loss-of-function, NLRP3 ubiquitination assay in rat macrophages\",\n      \"pmids\": [\"38530976\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"Indirect evidence through miRNA modulation; single ubiquitination method\", \"No acceptor-site mapping or reciprocal validation\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Provided a second context for MARCH3-mediated NLRP3 ubiquitination, in a neuronal Alzheimer's model where amyloid-\\u03b2 reduces the interaction.\",\n      \"evidence\": \"Endogenous Co-IP with ubiquitin immunoblot, SAMP8 AD mouse and A\\u03b21-42 cell models\",\n      \"pmids\": [\"39556273\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"Single Co-IP without reciprocal validation\", \"Direct catalytic activity on NLRP3 not demonstrated\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Established MARCH3 (with MARCH2) as an antiviral restriction factor by degrading the viral entry receptor TIM-1 via K48 linkage, limiting Zika virus infectivity in a TIM-1-dependent manner in vivo.\",\n      \"evidence\": \"Reciprocal Co-IP, K346/K338 mutagenesis, MARCH2/3 KO mice, TIM-1 KO reconstitution, ZIKV infection\",\n      \"pmids\": [\"40817191\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Breadth of TIM-1-dependent viruses restricted not defined\", \"Relative MARCH2/MARCH3 contribution not dissected\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Proposed MARCH3 degrades SIGLEC1 to inactivate NF-\\u03baB and protect retinal cells from hyperglycemic stress, adding another candidate substrate.\",\n      \"evidence\": \"Co-IP, cycloheximide chase, siRNA/overexpression in ARPE19 cells\",\n      \"pmids\": [\"40682693\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No mutagenesis of ubiquitination sites\", \"Single-lab, single-method interaction evidence\"]\n    },\n    {\n      \"year\": 2026,\n      \"claim\": \"Showed MARCH3 targets the glycolytic enzyme HK2 for degradation, suppressing glycolysis and tumor growth and enhancing chemosensitivity in nasopharyngeal carcinoma, reinforcing a metabolic/tumor-suppressive role.\",\n      \"evidence\": \"Co-IP, GST pull-down, cycloheximide chase, ubiquitination assay, in vivo NPC model\",\n      \"pmids\": [\"42044316\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Acceptor lysine and linkage type on HK2 not mapped\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"It remains unresolved what governs MARCH3's substrate selectivity and its choice of ubiquitin linkage type (K48 vs K27) and degradation route (lysosomal vs proteasomal) across its diverse membrane and cytoplasmic targets.\",\n      \"evidence\": \"Not addressed by current timeline\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No structural model of substrate recognition\", \"Mechanism of linkage-type selection unknown\", \"How a membrane ligase engages cytoplasmic/nuclear substrates like PARP1 unclear\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0016740\", \"supporting_discovery_ids\": [3, 4, 5, 6, 12]},\n      {\"term_id\": \"GO:0140096\", \"supporting_discovery_ids\": [3, 4, 5, 6, 12]},\n      {\"term_id\": \"GO:0016874\", \"supporting_discovery_ids\": [3, 5, 12]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005768\", \"supporting_discovery_ids\": [0]},\n      {\"term_id\": \"GO:0031410\", \"supporting_discovery_ids\": [0]},\n      {\"term_id\": \"GO:0005886\", \"supporting_discovery_ids\": [3, 12]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-168256\", \"supporting_discovery_ids\": [3, 4, 5, 6, 12]},\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [3, 4, 7]},\n      {\"term_id\": \"R-HSA-392499\", \"supporting_discovery_ids\": [3, 4, 5, 12]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\"IL1R1\", \"IL6R\", \"IL6ST\", \"IL3RA\", \"IL5RA\", \"HAVCR1\", \"GRB2\", \"STX6\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":5,"faith_total":6,"faith_pct":83.33333333333333}}