{"gene":"MYZAP","run_date":"2026-06-10T05:19:52","timeline":{"discoveries":[{"year":2010,"finding":"Myozap localizes to the intercalated disc (ID) of cardiomyocytes and directly binds desmoplakin and zonula occludens-1 (ZO-1), as established by yeast 2-hybrid and direct binding assays.","method":"Yeast 2-hybrid screen, direct binding assays, immunolocalization","journal":"Circulation Research","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — reciprocal binding confirmed by yeast 2-hybrid and direct assays in a single lab with multiple partners","pmids":["20093627"],"is_preprint":false},{"year":2010,"finding":"Myozap binds myosin phosphatase-RhoA interacting protein (MRIP), a negative regulator of Rho activity, identified in a yeast 2-hybrid screen.","method":"Yeast 2-hybrid screen","journal":"Circulation Research","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single yeast 2-hybrid screen, not further validated by orthogonal methods in the abstract","pmids":["20093627"],"is_preprint":false},{"year":2010,"finding":"Myozap activates SRF-dependent transcription through its ERM (Ezrin/radixin/moesin)-like domain in a RhoA-dependent manner.","method":"Transcriptional reporter assays, domain mutant analysis, Rho pathway inhibition","journal":"Circulation Research","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — reporter assay with domain-mapping and RhoA-dependency established in a single lab, replicated in overexpression mouse model","pmids":["20093627","24698889"],"is_preprint":false},{"year":2010,"finding":"In vivo knockdown of the Myozap ortholog in zebrafish leads to severe contractile dysfunction and cardiomyopathy, establishing a required role in cardiac function.","method":"Morpholino-mediated knockdown in zebrafish, cardiac function readout","journal":"Circulation Research","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — in vivo loss-of-function with defined phenotypic readout in a vertebrate model, single lab","pmids":["20093627"],"is_preprint":false},{"year":2012,"finding":"Myozap is a major component of the cytoplasmic plaques of adherens junctions in vascular endothelia, co-precipitating with N-cadherin, desmoplakin, desmoglein-2, plakophilin-2, plakoglobin, and plectin as stable complex partners.","method":"Immunoprecipitation, immunolocalization (light and electron microscopy), biochemical fractionation","journal":"Journal of Cellular and Molecular Medicine","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — rigorous immunoprecipitation with multiple partners confirmed in a single lab using multiple orthogonal methods","pmids":["21992629"],"is_preprint":false},{"year":2014,"finding":"Cardiac overexpression of Myozap in transgenic mice causes cardiomyopathy with hypertrophy, LV dilation, upregulation of SRF-dependent hypertrophy-associated genes, protein aggregate formation containing Myozap and desmoplakin, induction of autophagy, dysregulation of the unfolded protein response, and apoptosis.","method":"Cardiac-restricted transgenic mouse model, histology, electron microscopy, molecular pathway analysis","journal":"Journal of Molecular and Cellular Cardiology","confidence":"High","confidence_rationale":"Tier 2 / Strong — in vivo gain-of-function mouse model with multiple orthogonal readouts (ultrastructure, gene expression, autophagy, UPR, apoptosis), replicates in vitro RhoA/SRF mechanism","pmids":["24698889"],"is_preprint":false},{"year":2015,"finding":"Myozap-null (Mzp−/−) mice under pressure overload show accelerated cardiac hypertrophy with activation of β-catenin/GSK-3β signaling and inhibition of MAPK and MKL1/SRF pathways, and disorganization of intercalated disc proteins (N-cadherin, desmoplakin, connexin-43, ZO-1), establishing Myozap as a regulator of these signaling branches during biomechanical stress.","method":"Knockout mouse model, transverse aortic constriction, Western blotting, cardiac function assessment, immunohistochemistry","journal":"Journal of Biological Chemistry","confidence":"High","confidence_rationale":"Tier 2 / Strong — in vivo loss-of-function with defined signaling pathway dissection using multiple orthogonal methods in a single rigorous study","pmids":["26719331"],"is_preprint":false},{"year":2023,"finding":"YTHDF2, an m6A mRNA binding protein, binds m6A-modified Myzap mRNA and controls its stability; loss of YTHDF2 in cardiomyocytes leads to upregulation of MYZAP protein and adverse cardiac remodeling, identifying YTHDF2 as a post-transcriptional regulator of MYZAP expression.","method":"Cardiomyocyte-specific YTHDF2 knockout mice, proteomics, RNA immunoprecipitation, mRNA stability assay","journal":"JACC Basic to Translational Science","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — RNA binding and mRNA stability demonstrated by multiple methods in a single lab, functional cardiac consequence confirmed in vivo","pmids":["37791304"],"is_preprint":false},{"year":2020,"finding":"Dysbindin directly interacts with Myozap and its loss in sandy (Dtnbp1_KO) mice dramatically reduces Myozap protein levels in the heart, indicating Dysbindin is required for Myozap stability in vivo.","method":"Knockout mouse model (sandy mice), Western blotting, co-immunoprecipitation (implied by prior interaction data)","journal":"Cells","confidence":"Low","confidence_rationale":"Tier 3 / Weak — protein level changes demonstrated by Western blot in KO mice, but direct binding of Dysbindin–Myozap not independently confirmed by orthogonal method in this abstract","pmids":["33142804"],"is_preprint":false},{"year":2022,"finding":"Biallelic loss-of-function (homozygous premature termination) variant in MYZAP in human patients causes severe dilated cardiomyopathy; patient-derived iPSC-cardiomyocytes show significantly lower contractile force and prolonged time to peak contraction and relaxation, establishing a required role for MYZAP in human cardiomyocyte contractile function.","method":"Exome sequencing, Western blot, immunohistochemistry, electron microscopy, iPSC-derived cardiomyocyte contractility assay","journal":"Cold Spring Harbor Molecular Case Studies","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — functional validation in patient-derived iPSC-CMs with multiple orthogonal methods, single family/lab","pmids":["35840178"],"is_preprint":false},{"year":2024,"finding":"MYZAP overexpression in mouse atria (following myocardial infarction context) increases levels of PKP2 and Nav1.5 and reduces atrial fibrillation incidence, placing MYZAP upstream of PKP2 and Nav1.5 in a cardiac conduction regulatory pathway.","method":"Cardiac-specific transgenic MYZAP overexpression mice, AAV-mediated overexpression, AF incidence measurement, Western blotting","journal":"iScience","confidence":"Low","confidence_rationale":"Tier 3 / Weak — pathway placement inferred from overexpression experiment in a single study; mechanistic link between MYZAP and PKP2/Nav1.5 not biochemically dissected in the abstract","pmids":["39507261"],"is_preprint":false}],"current_model":"MYZAP (Myozap) is an intercalated disc and adherens junction scaffold protein that directly binds desmoplakin, ZO-1, N-cadherin, and other junctional proteins, and activates RhoA-dependent SRF transcriptional signaling through its ERM-like domain; loss of MYZAP impairs adaptation to biomechanical stress via dysregulation of β-catenin/GSK-3β and MAPK/MKL1-SRF pathways, while its overexpression drives cardiomyopathy through SRF activation, protein aggregate formation, UPR dysregulation, and autophagy induction; its mRNA stability is post-transcriptionally controlled by the m6A reader YTHDF2, and biallelic loss-of-function variants in humans cause severe dilated cardiomyopathy."},"narrative":{"mechanistic_narrative":"MYZAP (Myozap) is an intercalated disc and adherens junction scaffold protein that couples cardiac and vascular cell-cell junctions to RhoA-dependent SRF transcriptional signaling [PMID:20093627, PMID:24698889]. At the cardiomyocyte intercalated disc and in vascular endothelial adherens junction plaques, MYZAP directly binds desmoplakin and ZO-1 and assembles into a stable complex with junctional partners including N-cadherin, desmoglein-2, plakophilin-2, plakoglobin, and plectin [PMID:20093627, PMID:21992629]. Through its ERM-like domain, MYZAP activates SRF-dependent transcription in a RhoA-dependent manner [PMID:20093627, PMID:24698889]. MYZAP is required for normal contractile function, as ortholog knockdown produces cardiomyopathy in zebrafish [PMID:20093627] and biallelic loss-of-function variants cause severe human dilated cardiomyopathy with reduced contractile force in patient-derived iPSC-cardiomyocytes [PMID:35840178]. Loss of MYZAP under pressure overload accelerates cardiac hypertrophy with dysregulated β-catenin/GSK-3β signaling, suppressed MAPK and MKL1/SRF activity, and disorganized intercalated disc proteins, while cardiac overexpression drives hypertrophy, LV dilation, MYZAP/desmoplakin protein aggregates, autophagy induction, unfolded-protein-response dysregulation, and apoptosis [PMID:24698889, PMID:26719331]. MYZAP mRNA stability is post-transcriptionally controlled by the m6A reader YTHDF2 [PMID:37791304].","teleology":[{"year":2010,"claim":"Established MYZAP as an intercalated disc junctional scaffold by identifying its direct binding to desmoplakin and ZO-1, defining its physical place in the junctional architecture.","evidence":"Yeast 2-hybrid screen, direct binding assays, and immunolocalization in cardiomyocytes","pmids":["20093627"],"confidence":"Medium","gaps":["Binding interfaces/domains not mapped","Stoichiometry of the junctional complex undefined"]},{"year":2010,"claim":"Linked MYZAP to Rho regulation through interaction with the negative Rho regulator MRIP, hinting at a junction-to-signaling connection.","evidence":"Single yeast 2-hybrid screen","pmids":["20093627"],"confidence":"Low","gaps":["Not validated by orthogonal methods","Functional consequence of MRIP binding not established"]},{"year":2010,"claim":"Demonstrated that MYZAP transduces a transcriptional signal by activating SRF via its ERM-like domain in a RhoA-dependent manner, connecting junctional scaffolding to gene expression.","evidence":"Transcriptional reporter assays with domain mutants and Rho pathway inhibition, later corroborated in an overexpression mouse model","pmids":["20093627","24698889"],"confidence":"Medium","gaps":["Direct biochemical link between MYZAP and RhoA activation not resolved","How junctional localization gates SRF activity unknown"]},{"year":2010,"claim":"Showed MYZAP is required for cardiac contractile function in vivo, moving it from a binding partner to a functionally essential protein.","evidence":"Morpholino knockdown of the zebrafish ortholog with cardiac function readout","pmids":["20093627"],"confidence":"Medium","gaps":["Morpholino specificity/off-target concerns","Mechanism linking loss to contractile failure not dissected"]},{"year":2012,"claim":"Extended MYZAP beyond the heart by identifying it as a major cytoplasmic plaque component of vascular endothelial adherens junctions in a defined multiprotein complex.","evidence":"Immunoprecipitation, light and electron microscopy, and biochemical fractionation in vascular endothelia","pmids":["21992629"],"confidence":"Medium","gaps":["Direct vs indirect nature of each co-precipitating partner not separated","Endothelial functional role not tested"]},{"year":2014,"claim":"Defined the consequences of MYZAP excess, showing overexpression is itself pathogenic via SRF-driven hypertrophy, proteotoxic aggregation, autophagy, UPR dysregulation, and apoptosis.","evidence":"Cardiac-restricted transgenic mouse with histology, electron microscopy, and molecular pathway analysis","pmids":["24698889"],"confidence":"High","gaps":["Whether aggregation or SRF activation is the primary driver of disease unclear","Dose-response threshold for pathology undefined"]},{"year":2015,"claim":"Dissected MYZAP loss-of-function signaling, establishing it as a regulator balancing β-catenin/GSK-3β, MAPK, and MKL1/SRF pathways and maintaining intercalated disc organization under biomechanical stress.","evidence":"Knockout mice with transverse aortic constriction, Western blotting, and immunohistochemistry","pmids":["26719331"],"confidence":"High","gaps":["Direct effectors downstream of MYZAP in each branch not identified","Order/causality among the dysregulated pathways unresolved"]},{"year":2022,"claim":"Confirmed human disease relevance, showing biallelic loss-of-function MYZAP variants cause severe dilated cardiomyopathy with measurable contractile defects in patient cardiomyocytes.","evidence":"Exome sequencing plus iPSC-derived cardiomyocyte contractility assays and tissue analysis from a patient family","pmids":["35840178"],"confidence":"Medium","gaps":["Single family limits genetic generalizability","Molecular step from MYZAP loss to impaired contraction not pinpointed"]},{"year":2023,"claim":"Identified post-transcriptional control of MYZAP, showing the m6A reader YTHDF2 binds Myzap mRNA and governs its stability with cardiac consequences.","evidence":"Cardiomyocyte-specific YTHDF2 knockout mice, RNA immunoprecipitation, mRNA stability assays, and proteomics","pmids":["37791304"],"confidence":"Medium","gaps":["m6A site(s) on Myzap mRNA not mapped","Whether YTHDF2 effect on remodeling is solely MYZAP-mediated unclear"]},{"year":2020,"claim":"Implicated a protein-stability partner, with Dysbindin interaction and Dtnbp1 loss reducing cardiac MYZAP levels.","evidence":"Sandy (Dtnbp1 KO) mice with Western blotting and prior interaction data","pmids":["33142804"],"confidence":"Low","gaps":["Direct Dysbindin–MYZAP binding not confirmed by orthogonal method","Mechanism of stabilization unknown"]},{"year":2024,"claim":"Placed MYZAP upstream of conduction-related proteins, with overexpression raising PKP2 and Nav1.5 and reducing atrial fibrillation.","evidence":"Transgenic and AAV MYZAP overexpression mice with AF incidence and Western blotting","pmids":["39507261"],"confidence":"Low","gaps":["Biochemical link between MYZAP and PKP2/Nav1.5 not dissected","Inference from overexpression only"]},{"year":null,"claim":"How MYZAP mechanically and biochemically couples junctional binding to selective activation of RhoA/SRF versus suppression of β-catenin/MAPK branches, and the direct effectors mediating contractile output, remain unresolved.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No structural model of MYZAP or its complexes","Direct enzymatic/effector partners controlling RhoA undefined","Mechanism translating junctional scaffolding to contractile force unknown"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0060090","term_label":"molecular adaptor activity","supporting_discovery_ids":[0,4]},{"term_id":"GO:0140110","term_label":"transcription regulator activity","supporting_discovery_ids":[2]},{"term_id":"GO:0008092","term_label":"cytoskeletal protein binding","supporting_discovery_ids":[0,4]}],"localization":[{"term_id":"GO:0005829","term_label":"cytosol","supporting_discovery_ids":[0,4]},{"term_id":"GO:0005886","term_label":"plasma membrane","supporting_discovery_ids":[0,4]}],"pathway":[{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[2,6]},{"term_id":"R-HSA-1500931","term_label":"Cell-Cell communication","supporting_discovery_ids":[0,4]},{"term_id":"R-HSA-74160","term_label":"Gene expression (Transcription)","supporting_discovery_ids":[2,5]}],"complexes":["adherens junction plaque","intercalated disc"],"partners":["DSP","TJP1","CDH2","DSG2","PKP2","JUP","PLEC","MPRIP"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"P0CAP1","full_name":"Myocardial zonula adherens protein","aliases":["GRINL1A upstream protein","Gup"],"length_aa":466,"mass_kda":54.2,"function":"Plays a role in cellular signaling via Rho-related GTP-binding proteins and subsequent activation of transcription factor SRF (By similarity). Targets TJP1 to cell junctions. In cortical neurons, may play a role in glutaminergic signal transduction through interaction with the NMDA receptor subunit GRIN1 (By similarity)","subcellular_location":"Cytoplasm, cytoskeleton; Cell membrane; Cytoplasm, myofibril, sarcomere, I band; Cytoplasm, myofibril, sarcomere, Z line; Cell junction","url":"https://www.uniprot.org/uniprotkb/P0CAP1/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/MYZAP","classification":"Not Classified","n_dependent_lines":0,"n_total_lines":1208,"dependency_fraction":0.0},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/MYZAP","total_profiled":1310},"omim":[{"mim_id":"620894","title":"CARDIOMYOPATHY, DILATED, 2K; CMD2K","url":"https://www.omim.org/entry/620894"},{"mim_id":"614071","title":"MYOCARDIAL ZONULA ADHERENS PROTEIN; MYZAP","url":"https://www.omim.org/entry/614071"},{"mim_id":"606485","title":"POLYMERASE II, RNA, SUBUNIT M; POLR2M","url":"https://www.omim.org/entry/606485"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"","locations":[],"tissue_specificity":"Tissue enriched","tissue_distribution":"Detected in many","driving_tissues":[{"tissue":"heart muscle","ntpm":551.2}],"url":"https://www.proteinatlas.org/search/MYZAP"},"hgnc":{"alias_symbol":["MYOZAP","Gup","Gup1","GCOM1"],"prev_symbol":[]},"alphafold":{"accession":"P0CAP1","domains":[],"viewer_url":"https://alphafold.ebi.ac.uk/entry/P0CAP1","model_url":"https://alphafold.ebi.ac.uk/files/AF-P0CAP1-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-P0CAP1-F1-predicted_aligned_error_v6.png","plddt_mean":77.19},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=MYZAP","jax_strain_url":"https://www.jax.org/strain/search?query=MYZAP"},"sequence":{"accession":"P0CAP1","fasta_url":"https://rest.uniprot.org/uniprotkb/P0CAP1.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/P0CAP1/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/P0CAP1"}},"corpus_meta":[{"pmid":"20093627","id":"PMC_20093627","title":"Myozap, a novel intercalated disc protein, activates serum response factor-dependent signaling and is required to maintain cardiac function in vivo.","date":"2010","source":"Circulation research","url":"https://pubmed.ncbi.nlm.nih.gov/20093627","citation_count":53,"is_preprint":false},{"pmid":"30271950","id":"PMC_30271950","title":"Coding variants in RPL3L and MYZAP increase risk of atrial fibrillation.","date":"2018","source":"Communications biology","url":"https://pubmed.ncbi.nlm.nih.gov/30271950","citation_count":44,"is_preprint":false},{"pmid":"24698889","id":"PMC_24698889","title":"Mice with cardiac-restricted overexpression of Myozap are sensitized to biomechanical stress and develop a protein-aggregate-associated cardiomyopathy.","date":"2014","source":"Journal of molecular and cellular cardiology","url":"https://pubmed.ncbi.nlm.nih.gov/24698889","citation_count":27,"is_preprint":false},{"pmid":"26719331","id":"PMC_26719331","title":"Myozap Deficiency Promotes Adverse Cardiac Remodeling via Differential Regulation of Mitogen-activated Protein Kinase/Serum-response Factor and β-Catenin/GSK-3β Protein Signaling.","date":"2015","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/26719331","citation_count":27,"is_preprint":false},{"pmid":"21992629","id":"PMC_21992629","title":"The plaque protein myozap identified as a novel major component of adhering junctions in endothelia of the blood and the lymph vascular systems.","date":"2012","source":"Journal of cellular and molecular medicine","url":"https://pubmed.ncbi.nlm.nih.gov/21992629","citation_count":23,"is_preprint":false},{"pmid":"37791304","id":"PMC_37791304","title":"Loss of YTHDF2 Alters the Expression of m6A-Modified Myzap and Causes Adverse Cardiac Remodeling.","date":"2023","source":"JACC. Basic to translational science","url":"https://pubmed.ncbi.nlm.nih.gov/37791304","citation_count":17,"is_preprint":false},{"pmid":"22160502","id":"PMC_22160502","title":"Protein myozap--a late addition to the molecular ensembles of various kinds of adherens junctions.","date":"2011","source":"Cell and tissue research","url":"https://pubmed.ncbi.nlm.nih.gov/22160502","citation_count":13,"is_preprint":false},{"pmid":"34899865","id":"PMC_34899865","title":"GRINL1A Complex Transcription Unit Containing GCOM1, MYZAP, and POLR2M Genes Associates with Fully Penetrant Recessive Dilated Cardiomyopathy.","date":"2021","source":"Frontiers in genetics","url":"https://pubmed.ncbi.nlm.nih.gov/34899865","citation_count":11,"is_preprint":false},{"pmid":"29768670","id":"PMC_29768670","title":"Patients affected by a new variant of endemic pemphigus foliaceus have autoantibodies colocalizing with MYZAP, p0071, desmoplakins 1-2 and ARVCF, causing renal damage.","date":"2018","source":"Clinical and experimental dermatology","url":"https://pubmed.ncbi.nlm.nih.gov/29768670","citation_count":8,"is_preprint":false},{"pmid":"29152726","id":"PMC_29152726","title":"Autoantibodies to full body vascular cell junctions colocalize with MYZAP, ARVCF, desmoplakins I and II and p0071 in endemic pemphigus in Colombia, South America.","date":"2017","source":"International journal of dermatology","url":"https://pubmed.ncbi.nlm.nih.gov/29152726","citation_count":6,"is_preprint":false},{"pmid":"29034528","id":"PMC_29034528","title":"Patients with a new variant of endemic pemphigus foliaceus have autoantibodies against arrector pili muscle, colocalizing with MYZAP, p0071, desmoplakins 1 and 2 and ARVCF.","date":"2017","source":"Clinical and experimental dermatology","url":"https://pubmed.ncbi.nlm.nih.gov/29034528","citation_count":5,"is_preprint":false},{"pmid":"35840178","id":"PMC_35840178","title":"A biallelic loss-of-function variant in MYZAP is associated with a recessive form of severe dilated cardiomyopathy.","date":"2022","source":"Cold Spring Harbor molecular case studies","url":"https://pubmed.ncbi.nlm.nih.gov/35840178","citation_count":5,"is_preprint":false},{"pmid":"39507261","id":"PMC_39507261","title":"CCRR regulate MYZAP-PKP2-Nav1.5 signaling pathway in atrial fibrillation following myocardial infarction.","date":"2024","source":"iScience","url":"https://pubmed.ncbi.nlm.nih.gov/39507261","citation_count":2,"is_preprint":false},{"pmid":"33142804","id":"PMC_33142804","title":"Dysbindin deficiency Alters Cardiac BLOC-1 Complex and Myozap Levels in Mice.","date":"2020","source":"Cells","url":"https://pubmed.ncbi.nlm.nih.gov/33142804","citation_count":2,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":9101,"output_tokens":2539,"usd":0.032694,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":9738,"output_tokens":3487,"usd":0.067933,"stage2_stop_reason":"end_turn"},"total_usd":0.100627,"stage1_batch_id":"msgbatch_013a8chtv3AWyTqv4z4sEF4C","stage2_batch_id":"msgbatch_01AHsuW63vinsvuTgzmQ3n62","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2010,\n      \"finding\": \"Myozap localizes to the intercalated disc (ID) of cardiomyocytes and directly binds desmoplakin and zonula occludens-1 (ZO-1), as established by yeast 2-hybrid and direct binding assays.\",\n      \"method\": \"Yeast 2-hybrid screen, direct binding assays, immunolocalization\",\n      \"journal\": \"Circulation Research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — reciprocal binding confirmed by yeast 2-hybrid and direct assays in a single lab with multiple partners\",\n      \"pmids\": [\"20093627\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"Myozap binds myosin phosphatase-RhoA interacting protein (MRIP), a negative regulator of Rho activity, identified in a yeast 2-hybrid screen.\",\n      \"method\": \"Yeast 2-hybrid screen\",\n      \"journal\": \"Circulation Research\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single yeast 2-hybrid screen, not further validated by orthogonal methods in the abstract\",\n      \"pmids\": [\"20093627\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"Myozap activates SRF-dependent transcription through its ERM (Ezrin/radixin/moesin)-like domain in a RhoA-dependent manner.\",\n      \"method\": \"Transcriptional reporter assays, domain mutant analysis, Rho pathway inhibition\",\n      \"journal\": \"Circulation Research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — reporter assay with domain-mapping and RhoA-dependency established in a single lab, replicated in overexpression mouse model\",\n      \"pmids\": [\"20093627\", \"24698889\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"In vivo knockdown of the Myozap ortholog in zebrafish leads to severe contractile dysfunction and cardiomyopathy, establishing a required role in cardiac function.\",\n      \"method\": \"Morpholino-mediated knockdown in zebrafish, cardiac function readout\",\n      \"journal\": \"Circulation Research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — in vivo loss-of-function with defined phenotypic readout in a vertebrate model, single lab\",\n      \"pmids\": [\"20093627\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"Myozap is a major component of the cytoplasmic plaques of adherens junctions in vascular endothelia, co-precipitating with N-cadherin, desmoplakin, desmoglein-2, plakophilin-2, plakoglobin, and plectin as stable complex partners.\",\n      \"method\": \"Immunoprecipitation, immunolocalization (light and electron microscopy), biochemical fractionation\",\n      \"journal\": \"Journal of Cellular and Molecular Medicine\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — rigorous immunoprecipitation with multiple partners confirmed in a single lab using multiple orthogonal methods\",\n      \"pmids\": [\"21992629\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"Cardiac overexpression of Myozap in transgenic mice causes cardiomyopathy with hypertrophy, LV dilation, upregulation of SRF-dependent hypertrophy-associated genes, protein aggregate formation containing Myozap and desmoplakin, induction of autophagy, dysregulation of the unfolded protein response, and apoptosis.\",\n      \"method\": \"Cardiac-restricted transgenic mouse model, histology, electron microscopy, molecular pathway analysis\",\n      \"journal\": \"Journal of Molecular and Cellular Cardiology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — in vivo gain-of-function mouse model with multiple orthogonal readouts (ultrastructure, gene expression, autophagy, UPR, apoptosis), replicates in vitro RhoA/SRF mechanism\",\n      \"pmids\": [\"24698889\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"Myozap-null (Mzp−/−) mice under pressure overload show accelerated cardiac hypertrophy with activation of β-catenin/GSK-3β signaling and inhibition of MAPK and MKL1/SRF pathways, and disorganization of intercalated disc proteins (N-cadherin, desmoplakin, connexin-43, ZO-1), establishing Myozap as a regulator of these signaling branches during biomechanical stress.\",\n      \"method\": \"Knockout mouse model, transverse aortic constriction, Western blotting, cardiac function assessment, immunohistochemistry\",\n      \"journal\": \"Journal of Biological Chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — in vivo loss-of-function with defined signaling pathway dissection using multiple orthogonal methods in a single rigorous study\",\n      \"pmids\": [\"26719331\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"YTHDF2, an m6A mRNA binding protein, binds m6A-modified Myzap mRNA and controls its stability; loss of YTHDF2 in cardiomyocytes leads to upregulation of MYZAP protein and adverse cardiac remodeling, identifying YTHDF2 as a post-transcriptional regulator of MYZAP expression.\",\n      \"method\": \"Cardiomyocyte-specific YTHDF2 knockout mice, proteomics, RNA immunoprecipitation, mRNA stability assay\",\n      \"journal\": \"JACC Basic to Translational Science\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — RNA binding and mRNA stability demonstrated by multiple methods in a single lab, functional cardiac consequence confirmed in vivo\",\n      \"pmids\": [\"37791304\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"Dysbindin directly interacts with Myozap and its loss in sandy (Dtnbp1_KO) mice dramatically reduces Myozap protein levels in the heart, indicating Dysbindin is required for Myozap stability in vivo.\",\n      \"method\": \"Knockout mouse model (sandy mice), Western blotting, co-immunoprecipitation (implied by prior interaction data)\",\n      \"journal\": \"Cells\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — protein level changes demonstrated by Western blot in KO mice, but direct binding of Dysbindin–Myozap not independently confirmed by orthogonal method in this abstract\",\n      \"pmids\": [\"33142804\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"Biallelic loss-of-function (homozygous premature termination) variant in MYZAP in human patients causes severe dilated cardiomyopathy; patient-derived iPSC-cardiomyocytes show significantly lower contractile force and prolonged time to peak contraction and relaxation, establishing a required role for MYZAP in human cardiomyocyte contractile function.\",\n      \"method\": \"Exome sequencing, Western blot, immunohistochemistry, electron microscopy, iPSC-derived cardiomyocyte contractility assay\",\n      \"journal\": \"Cold Spring Harbor Molecular Case Studies\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — functional validation in patient-derived iPSC-CMs with multiple orthogonal methods, single family/lab\",\n      \"pmids\": [\"35840178\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"MYZAP overexpression in mouse atria (following myocardial infarction context) increases levels of PKP2 and Nav1.5 and reduces atrial fibrillation incidence, placing MYZAP upstream of PKP2 and Nav1.5 in a cardiac conduction regulatory pathway.\",\n      \"method\": \"Cardiac-specific transgenic MYZAP overexpression mice, AAV-mediated overexpression, AF incidence measurement, Western blotting\",\n      \"journal\": \"iScience\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — pathway placement inferred from overexpression experiment in a single study; mechanistic link between MYZAP and PKP2/Nav1.5 not biochemically dissected in the abstract\",\n      \"pmids\": [\"39507261\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"MYZAP (Myozap) is an intercalated disc and adherens junction scaffold protein that directly binds desmoplakin, ZO-1, N-cadherin, and other junctional proteins, and activates RhoA-dependent SRF transcriptional signaling through its ERM-like domain; loss of MYZAP impairs adaptation to biomechanical stress via dysregulation of β-catenin/GSK-3β and MAPK/MKL1-SRF pathways, while its overexpression drives cardiomyopathy through SRF activation, protein aggregate formation, UPR dysregulation, and autophagy induction; its mRNA stability is post-transcriptionally controlled by the m6A reader YTHDF2, and biallelic loss-of-function variants in humans cause severe dilated cardiomyopathy.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"MYZAP (Myozap) is an intercalated disc and adherens junction scaffold protein that couples cardiac and vascular cell-cell junctions to RhoA-dependent SRF transcriptional signaling [#0, #2]. At the cardiomyocyte intercalated disc and in vascular endothelial adherens junction plaques, MYZAP directly binds desmoplakin and ZO-1 and assembles into a stable complex with junctional partners including N-cadherin, desmoglein-2, plakophilin-2, plakoglobin, and plectin [#0, #4]. Through its ERM-like domain, MYZAP activates SRF-dependent transcription in a RhoA-dependent manner [#2]. MYZAP is required for normal contractile function, as ortholog knockdown produces cardiomyopathy in zebrafish [#3] and biallelic loss-of-function variants cause severe human dilated cardiomyopathy with reduced contractile force in patient-derived iPSC-cardiomyocytes [#9]. Loss of MYZAP under pressure overload accelerates cardiac hypertrophy with dysregulated \\u03b2-catenin/GSK-3\\u03b2 signaling, suppressed MAPK and MKL1/SRF activity, and disorganized intercalated disc proteins, while cardiac overexpression drives hypertrophy, LV dilation, MYZAP/desmoplakin protein aggregates, autophagy induction, unfolded-protein-response dysregulation, and apoptosis [#5, #6]. MYZAP mRNA stability is post-transcriptionally controlled by the m6A reader YTHDF2 [#7].\"\n,\n  \"teleology\": [\n    {\n      \"year\": 2010,\n      \"claim\": \"Established MYZAP as an intercalated disc junctional scaffold by identifying its direct binding to desmoplakin and ZO-1, defining its physical place in the junctional architecture.\",\n      \"evidence\": \"Yeast 2-hybrid screen, direct binding assays, and immunolocalization in cardiomyocytes\",\n      \"pmids\": [\"20093627\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Binding interfaces/domains not mapped\", \"Stoichiometry of the junctional complex undefined\"]\n    },\n    {\n      \"year\": 2010,\n      \"claim\": \"Linked MYZAP to Rho regulation through interaction with the negative Rho regulator MRIP, hinting at a junction-to-signaling connection.\",\n      \"evidence\": \"Single yeast 2-hybrid screen\",\n      \"pmids\": [\"20093627\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"Not validated by orthogonal methods\", \"Functional consequence of MRIP binding not established\"]\n    },\n    {\n      \"year\": 2010,\n      \"claim\": \"Demonstrated that MYZAP transduces a transcriptional signal by activating SRF via its ERM-like domain in a RhoA-dependent manner, connecting junctional scaffolding to gene expression.\",\n      \"evidence\": \"Transcriptional reporter assays with domain mutants and Rho pathway inhibition, later corroborated in an overexpression mouse model\",\n      \"pmids\": [\"20093627\", \"24698889\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct biochemical link between MYZAP and RhoA activation not resolved\", \"How junctional localization gates SRF activity unknown\"]\n    },\n    {\n      \"year\": 2010,\n      \"claim\": \"Showed MYZAP is required for cardiac contractile function in vivo, moving it from a binding partner to a functionally essential protein.\",\n      \"evidence\": \"Morpholino knockdown of the zebrafish ortholog with cardiac function readout\",\n      \"pmids\": [\"20093627\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Morpholino specificity/off-target concerns\", \"Mechanism linking loss to contractile failure not dissected\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Extended MYZAP beyond the heart by identifying it as a major cytoplasmic plaque component of vascular endothelial adherens junctions in a defined multiprotein complex.\",\n      \"evidence\": \"Immunoprecipitation, light and electron microscopy, and biochemical fractionation in vascular endothelia\",\n      \"pmids\": [\"21992629\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct vs indirect nature of each co-precipitating partner not separated\", \"Endothelial functional role not tested\"]\n    },\n    {\n      \"year\": 2014,\n      \"claim\": \"Defined the consequences of MYZAP excess, showing overexpression is itself pathogenic via SRF-driven hypertrophy, proteotoxic aggregation, autophagy, UPR dysregulation, and apoptosis.\",\n      \"evidence\": \"Cardiac-restricted transgenic mouse with histology, electron microscopy, and molecular pathway analysis\",\n      \"pmids\": [\"24698889\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether aggregation or SRF activation is the primary driver of disease unclear\", \"Dose-response threshold for pathology undefined\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"Dissected MYZAP loss-of-function signaling, establishing it as a regulator balancing \\u03b2-catenin/GSK-3\\u03b2, MAPK, and MKL1/SRF pathways and maintaining intercalated disc organization under biomechanical stress.\",\n      \"evidence\": \"Knockout mice with transverse aortic constriction, Western blotting, and immunohistochemistry\",\n      \"pmids\": [\"26719331\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Direct effectors downstream of MYZAP in each branch not identified\", \"Order/causality among the dysregulated pathways unresolved\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Confirmed human disease relevance, showing biallelic loss-of-function MYZAP variants cause severe dilated cardiomyopathy with measurable contractile defects in patient cardiomyocytes.\",\n      \"evidence\": \"Exome sequencing plus iPSC-derived cardiomyocyte contractility assays and tissue analysis from a patient family\",\n      \"pmids\": [\"35840178\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single family limits genetic generalizability\", \"Molecular step from MYZAP loss to impaired contraction not pinpointed\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Identified post-transcriptional control of MYZAP, showing the m6A reader YTHDF2 binds Myzap mRNA and governs its stability with cardiac consequences.\",\n      \"evidence\": \"Cardiomyocyte-specific YTHDF2 knockout mice, RNA immunoprecipitation, mRNA stability assays, and proteomics\",\n      \"pmids\": [\"37791304\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"m6A site(s) on Myzap mRNA not mapped\", \"Whether YTHDF2 effect on remodeling is solely MYZAP-mediated unclear\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Implicated a protein-stability partner, with Dysbindin interaction and Dtnbp1 loss reducing cardiac MYZAP levels.\",\n      \"evidence\": \"Sandy (Dtnbp1 KO) mice with Western blotting and prior interaction data\",\n      \"pmids\": [\"33142804\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"Direct Dysbindin\\u2013MYZAP binding not confirmed by orthogonal method\", \"Mechanism of stabilization unknown\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Placed MYZAP upstream of conduction-related proteins, with overexpression raising PKP2 and Nav1.5 and reducing atrial fibrillation.\",\n      \"evidence\": \"Transgenic and AAV MYZAP overexpression mice with AF incidence and Western blotting\",\n      \"pmids\": [\"39507261\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"Biochemical link between MYZAP and PKP2/Nav1.5 not dissected\", \"Inference from overexpression only\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How MYZAP mechanically and biochemically couples junctional binding to selective activation of RhoA/SRF versus suppression of \\u03b2-catenin/MAPK branches, and the direct effectors mediating contractile output, remain unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No structural model of MYZAP or its complexes\", \"Direct enzymatic/effector partners controlling RhoA undefined\", \"Mechanism translating junctional scaffolding to contractile force unknown\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0060090\", \"supporting_discovery_ids\": [0, 4]},\n      {\"term_id\": \"GO:0140110\", \"supporting_discovery_ids\": [2]},\n      {\"term_id\": \"GO:0008092\", \"supporting_discovery_ids\": [0, 4]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005829\", \"supporting_discovery_ids\": [0, 4]},\n      {\"term_id\": \"GO:0005886\", \"supporting_discovery_ids\": [0, 4]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [2, 6]},\n      {\"term_id\": \"R-HSA-1500931\", \"supporting_discovery_ids\": [0, 4]},\n      {\"term_id\": \"R-HSA-74160\", \"supporting_discovery_ids\": [2, 5]}\n    ],\n    \"complexes\": [\"adherens junction plaque\", \"intercalated disc\"],\n    \"partners\": [\"DSP\", \"TJP1\", \"CDH2\", \"DSG2\", \"PKP2\", \"JUP\", \"PLEC\", \"MPRIP\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":6,"faith_total":6,"faith_pct":100.0}}