{"gene":"GNAZ","run_date":"2026-04-28T18:06:53","timeline":{"discoveries":[{"year":1988,"finding":"GNAZ was chromosomally localized to human chromosome 22 by hybridization of cDNA clones with DNA from human-mouse somatic cell hybrids, establishing its genomic position within the G protein alpha-subunit gene family.","method":"Somatic cell hybrid panel + cDNA hybridization","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"High","confidence_rationale":"Tier 1 — direct genomic mapping with molecular probes, foundational study replicated by subsequent mapping papers","pmids":["2902634"],"is_preprint":false},{"year":1995,"finding":"GNAZ is expressed in human fetal cochlea, specifically localized by in situ hybridization and immunohistochemistry, suggesting a role in maintaining ionic balance of perilymphatic and endolymphatic cochlear fluids.","method":"Northern blot, tissue in situ hybridization, immunohistochemistry","journal":"Hearing research","confidence":"Medium","confidence_rationale":"Tier 2 — direct localization by multiple methods but functional role is inferred, single lab","pmids":["8975005"],"is_preprint":false},{"year":2013,"finding":"Gαz (GNAZ) is localized to axonal growth cones in cortical neurons and inhibits BDNF-stimulated axon growth, establishing an endogenous role in regulating neurotrophin signaling in the CNS.","method":"Gz knockout mouse cortical neurons (ex vivo and cultured), immunolocalization, axon growth assays","journal":"Molecular and cellular neurosciences","confidence":"High","confidence_rationale":"Tier 2 — clean KO with defined cellular phenotype (axon growth), direct localization, multiple experimental approaches","pmids":["24321455"],"is_preprint":false},{"year":2014,"finding":"Gnaz is expressed in enteric axons and couples Smoothened (Smo) signaling downstream of Sonic Hedgehog (Shh) to mediate axon repulsion; knockdown or dominant-negative inhibition of Gnaz dampens the axon-repulsive response to Shh, and Gnaz mutant intestines contain centrally projected enteric axons.","method":"Enteric neuron knockdown, dominant-negative inhibition, Gnaz mutant mouse intestines, in vitro axon turning assay","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"High","confidence_rationale":"Tier 2 — genetic KO with specific anatomical phenotype plus in vitro functional assay and dominant-negative, multiple orthogonal methods","pmids":["25535338"],"is_preprint":false},{"year":2017,"finding":"Gnaz is expressed in photoreceptors and its protein product Gαz shows a daily rhythm in subcellular localization; Gnaz expression rhythm is dependent on the circadian Clock gene and dopamine D4 receptors, linking the circadian clockwork via dopamine to G protein-mediated signaling in retinal photoreceptors.","method":"Microdissected photoreceptors, whole retina preparations, Clock and D4 receptor knockout mice, subcellular fractionation/immunolocalization, constant darkness experiments","journal":"PloS one","confidence":"High","confidence_rationale":"Tier 2 — multiple genetic models (Clock KO, D4R KO, db/db), direct subcellular localization experiments, replicated across conditions","pmids":["29088301"],"is_preprint":false},{"year":2023,"finding":"GNAZ sequesters ADAM17 under normal conditions; blue light illumination disrupts the GNAZ-ADAM17 interaction, allowing ADAM17 to hyperactivate and cleave claudin-5 (CLDN5), collapsing the inner blood-retinal barrier. GNAZ knockdown phenocopies blue light exposure by causing ADAM17 hyperactivation, CLDN5 downregulation, and paracellular permeability.","method":"GNAZ knockdown (in vitro and in vivo), pharmacological and genetic ADAM17 inhibition, co-immunoprecipitation (GNAZ-ADAM17 interaction), tight junction permeability assays, electroretinogram, mouse blue-light exposure model","journal":"Fluids and barriers of the CNS","confidence":"High","confidence_rationale":"Tier 2 — reciprocal interaction demonstrated, KD phenotype with specific molecular readout, in vitro and in vivo validation, multiple orthogonal methods","pmids":["37095509"],"is_preprint":false},{"year":2025,"finding":"In mouse pancreatic islets, FFAR4 activation stimulates insulin secretion indirectly through Gαz-coupled inhibition of somatostatin (SST) secretion from δ cells; Gnaz deletion prevents FFAR4 agonist inhibition of SST secretion and abolishes the reduction in Ca2+ transients in δ cells, but does not prevent direct insulin potentiation in human islets.","method":"Gnaz knockout mouse islets, δ-cell ablation, SST-deficient mice, purified β and δ cells, Ca2+ imaging, insulin/SST secretion assays","journal":"bioRxiv","confidence":"High","confidence_rationale":"Tier 1-2 — clean KO with specific secretory phenotype, Ca2+ dynamics, multiple genetic controls and cell-type-specific dissection","pmids":["40894772"],"is_preprint":true},{"year":2023,"finding":"GNAZ promotes hepatocellular carcinoma vasculogenic mimicry by phosphorylating components of the ERK pathway; it is a direct target of miR-20a-3p, and its expression is transcriptionally regulated by E2F1 via the CDKN2B-AS1/E2F1/GNAZ axis.","method":"Dual-luciferase reporter assay, chromatin immunoprecipitation, lentivirus-mediated miR-20a-3p overexpression, transcriptome sequencing, in vitro tube formation and in vivo VM/metastasis assays","journal":"Research (Washington, D.C.)","confidence":"Medium","confidence_rationale":"Tier 2 — luciferase and ChIP validate transcriptional regulation; ERK phosphorylation link is mechanistic but from single lab","pmids":["41306771"],"is_preprint":false},{"year":2023,"finding":"CDKN2B-AS1 lncRNA recruits E2F1 to the GNAZ promoter region to facilitate GNAZ transcription, promoting HCC cell proliferation and survival; RNA immunoprecipitation confirmed CDKN2B-AS1-E2F1 interaction and ChIP verified E2F1 binding to the GNAZ promoter.","method":"RNA immunoprecipitation, chromatin immunoprecipitation, luciferase reporter assay, CDKN2B-AS1 knockdown with GNAZ/E2F1 rescue experiments","journal":"World journal of gastrointestinal oncology","confidence":"Medium","confidence_rationale":"Tier 2 — RIP and ChIP validate interaction; single lab, convergent with IF1/ESR1/miR-20a-3p study","pmids":["38077646"],"is_preprint":false},{"year":2021,"finding":"A somatic variant in GNAZ found in a plexiform neurofibroma leads to increased ERK1/2 activation compared to wild-type GNAZ, suggesting GNAZ can activate the MAPK pathway when mutated.","method":"Whole-exome sequencing, ERK1/2 phosphorylation assay in cells expressing mutant vs. wild-type GNAZ","journal":"Experimental dermatology","confidence":"Low","confidence_rationale":"Tier 3 — single case study, single signaling readout, limited controls","pmids":["34913528"],"is_preprint":false}],"current_model":"GNAZ encodes Gαz, a pertussis toxin-insensitive inhibitory G protein alpha subunit that localizes to axonal growth cones, photoreceptor subcellular compartments, and retinal endothelial cells, where it inhibits BDNF-stimulated axon growth, couples circadian/dopaminergic input to photoreceptor G protein signaling via D4 receptors, sequesters ADAM17 to protect the inner blood-retinal barrier, mediates Sonic Hedgehog-driven enteric axon repulsion through Smoothened, and in pancreatic δ cells couples FFAR4 activation to inhibition of somatostatin secretion, thereby indirectly stimulating insulin release; transcriptionally, GNAZ is regulated by a CDKN2B-AS1/E2F1 axis and is post-transcriptionally suppressed by miR-20a-3p, with mutant forms activating ERK/MAPK signaling."},"narrative":{"teleology":[{"year":1988,"claim":"The chromosomal position of GNAZ was unknown among the expanding G protein alpha-subunit family; somatic cell hybrid mapping placed it on human chromosome 22, anchoring it genomically.","evidence":"cDNA hybridization to human-mouse somatic cell hybrid DNA panel","pmids":["2902634"],"confidence":"High","gaps":["No functional data at this stage","Expression pattern undefined"]},{"year":1995,"claim":"Whether GNAZ was expressed outside the brain was unclear; detection of Gαz mRNA and protein in human fetal cochlea expanded the tissue repertoire and suggested involvement in ionic homeostasis of cochlear fluids.","evidence":"Northern blot, in situ hybridization, and immunohistochemistry on human fetal cochlea","pmids":["8975005"],"confidence":"Medium","gaps":["Functional role in cochlea remains inferred from localization only","No loss-of-function data in this tissue"]},{"year":2013,"claim":"It was not known whether Gαz had a cell-autonomous role in CNS axon development; Gnaz knockout cortical neurons showed enhanced BDNF-stimulated axon growth, establishing Gαz as an endogenous brake on neurotrophin-driven axon extension.","evidence":"Gnaz knockout mouse cortical neurons, immunolocalization to growth cones, axon length assays","pmids":["24321455"],"confidence":"High","gaps":["Receptor upstream of Gαz in cortical neurons not identified","Downstream effector linking Gαz to growth cone cytoskeleton unknown"]},{"year":2014,"claim":"How Sonic Hedgehog repels enteric axons was unresolved; this work showed that Gαz couples the Smoothened receptor to an axon-repulsive output, and Gnaz-mutant intestines exhibit misprojected enteric axons.","evidence":"Gnaz knockdown and dominant-negative inhibition in enteric neurons, axon turning assay, Gnaz mutant mouse intestines","pmids":["25535338"],"confidence":"High","gaps":["Effector between Gαz and cytoskeletal rearrangement in enteric growth cones uncharacterized","Whether Gαz-Smo coupling is direct or requires an intermediate is unresolved"]},{"year":2017,"claim":"How circadian and dopaminergic signals converge on photoreceptor G protein signaling was unknown; Gαz was shown to undergo daily rhythmic subcellular redistribution in photoreceptors dependent on Clock and dopamine D4 receptors.","evidence":"Microdissected photoreceptors from Clock KO and D4R KO mice, subcellular fractionation, constant-darkness paradigm","pmids":["29088301"],"confidence":"High","gaps":["Downstream effector of Gαz in photoreceptor signaling not identified","Mechanism driving Gαz subcellular translocation unclear"]},{"year":2021,"claim":"Whether GNAZ variants could activate oncogenic signaling was untested; a somatic GNAZ variant in a plexiform neurofibroma increased ERK1/2 phosphorylation relative to wild-type, linking mutant Gαz to MAPK pathway activation.","evidence":"Whole-exome sequencing of tumor, ERK phosphorylation assay comparing mutant and wild-type GNAZ in cell lines","pmids":["34913528"],"confidence":"Low","gaps":["Single case with limited controls","Mechanism by which mutant Gαz activates ERK unknown","Not independently confirmed in additional tumors"]},{"year":2023,"claim":"The mechanism protecting the inner blood-retinal barrier from sheddase activity was unclear; Gαz was shown to sequester ADAM17, and disruption of this interaction (by blue light or GNAZ knockdown) hyperactivates ADAM17, cleaves claudin-5, and increases paracellular permeability.","evidence":"Co-immunoprecipitation of GNAZ-ADAM17, GNAZ knockdown in vitro and in vivo, tight junction permeability assays, mouse blue-light model","pmids":["37095509"],"confidence":"High","gaps":["Structural basis of the GNAZ-ADAM17 interaction unknown","Whether Gαz GTPase activity is required for ADAM17 sequestration untested"]},{"year":2023,"claim":"Transcriptional control of GNAZ was undefined; the CDKN2B-AS1 lncRNA was found to recruit E2F1 to the GNAZ promoter, driving transcription, and miR-20a-3p was identified as a direct post-transcriptional suppressor, with GNAZ overexpression promoting ERK-dependent vasculogenic mimicry in hepatocellular carcinoma.","evidence":"RNA immunoprecipitation, ChIP, dual-luciferase reporters, miR-20a-3p overexpression, in vivo VM/metastasis assays in HCC models","pmids":["38077646","41306771"],"confidence":"Medium","gaps":["Findings from a single group; independent replication needed","Whether ERK activation by wild-type Gαz in HCC uses the same mechanism as the tumor-derived mutant is unknown","Role of GTPase cycle in ERK activation not dissected"]},{"year":2025,"claim":"How FFAR4 agonists stimulate insulin secretion was incompletely understood; Gnaz deletion in mouse δ cells abolished FFAR4-mediated inhibition of somatostatin secretion and the associated Ca²⁺ transient reduction, demonstrating Gαz as the coupling G protein in δ cells for paracrine regulation of insulin release.","evidence":"(preprint) Gnaz knockout mouse islets, δ-cell ablation, SST-deficient mice, Ca²⁺ imaging, insulin/SST secretion assays","pmids":["40894772"],"confidence":"High","gaps":["Preprint; not yet peer-reviewed","Mechanism differs between mouse and human islets — human δ-cell coupling not fully resolved","Direct Gαz–FFAR4 physical interaction not demonstrated"]},{"year":null,"claim":"The immediate downstream effectors of Gαz in most contexts (growth cones, photoreceptors, enteric axons) remain unidentified, and no structural model of Gαz interaction with ADAM17 or Smoothened exists.","evidence":"","pmids":[],"confidence":"Low","gaps":["No effector identified for Gαz in axon growth or retinal signaling","Structural basis of GNAZ-ADAM17 and GNAZ-Smo coupling unknown","In vivo relevance of GNAZ-ERK axis in human cancer not established"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0003924","term_label":"GTPase activity","supporting_discovery_ids":[2,3,4,6]},{"term_id":"GO:0060089","term_label":"molecular transducer activity","supporting_discovery_ids":[3,4,6]},{"term_id":"GO:0140313","term_label":"molecular sequestering activity","supporting_discovery_ids":[5]}],"localization":[{"term_id":"GO:0005886","term_label":"plasma membrane","supporting_discovery_ids":[2,4,5]},{"term_id":"GO:0005829","term_label":"cytosol","supporting_discovery_ids":[4]}],"pathway":[{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[2,3,4,5,6,7,9]},{"term_id":"R-HSA-1266738","term_label":"Developmental Biology","supporting_discovery_ids":[3]},{"term_id":"R-HSA-112316","term_label":"Neuronal System","supporting_discovery_ids":[2,3]},{"term_id":"R-HSA-9709957","term_label":"Sensory Perception","supporting_discovery_ids":[4]}],"complexes":[],"partners":["ADAM17","SMO","FFAR4","E2F1","DRD4"],"other_free_text":[]},"mechanistic_narrative":"GNAZ encodes Gαz, a pertussis toxin-insensitive inhibitory heterotrimeric G protein alpha subunit that transduces signals from diverse receptors to regulate axon guidance, photoreceptor physiology, barrier integrity, and endocrine secretion. Gαz localizes to axonal growth cones where it inhibits BDNF-stimulated axon growth and couples Smoothened signaling downstream of Sonic Hedgehog to mediate enteric axon repulsion [PMID:24321455, PMID:25535338]. In the retina, Gαz undergoes circadian- and dopamine D4 receptor-dependent rhythmic redistribution in photoreceptors and sequesters the sheddase ADAM17 in retinal endothelial cells, preventing claudin-5 cleavage and preserving inner blood-retinal barrier integrity [PMID:29088301, PMID:37095509]. GNAZ transcription is driven by a CDKN2B-AS1/E2F1 axis and post-transcriptionally suppressed by miR-20a-3p, and in hepatocellular carcinoma its overexpression activates ERK/MAPK signaling to promote vasculogenic mimicry [PMID:38077646, PMID:41306771]."},"prefetch_data":{"uniprot":{"accession":"P19086","full_name":"Guanine nucleotide-binding protein G(z) subunit alpha","aliases":["G(x) alpha chain","Gz-alpha"],"length_aa":355,"mass_kda":40.9,"function":"Guanine nucleotide-binding proteins (G proteins) are involved as modulators or transducers in various transmembrane signaling systems","subcellular_location":"Membrane","url":"https://www.uniprot.org/uniprotkb/P19086/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/GNAZ","classification":"Not Classified","n_dependent_lines":4,"n_total_lines":1208,"dependency_fraction":0.0033112582781456954},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/GNAZ","total_profiled":1310},"omim":[{"mim_id":"611240","title":"GPRIN FAMILY, MEMBER 2; GPRIN2","url":"https://www.omim.org/entry/611240"},{"mim_id":"611239","title":"GPRIN FAMILY, MEMBER 1; GPRIN1","url":"https://www.omim.org/entry/611239"},{"mim_id":"607193","title":"REGULATOR OF G PROTEIN SIGNALING 20; RGS20","url":"https://www.omim.org/entry/607193"},{"mim_id":"139160","title":"GUANINE NUCLEOTIDE-BINDING PROTEIN, ALPHA Z POLYPEPTIDE; GNAZ","url":"https://www.omim.org/entry/139160"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Approved","locations":[{"location":"Vesicles","reliability":"Approved"}],"tissue_specificity":"Tissue enhanced","tissue_distribution":"Detected in many","driving_tissues":[{"tissue":"brain","ntpm":45.1}],"url":"https://www.proteinatlas.org/search/GNAZ"},"hgnc":{"alias_symbol":[],"prev_symbol":[]},"alphafold":{"accession":"P19086","domains":[{"cath_id":"1.10.400.10","chopping":"62-176","consensus_level":"high","plddt":96.8352,"start":62,"end":176},{"cath_id":"3.40.50.300","chopping":"216-340","consensus_level":"high","plddt":96.3978,"start":216,"end":340}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/P19086","model_url":"https://alphafold.ebi.ac.uk/files/AF-P19086-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-P19086-F1-predicted_aligned_error_v6.png","plddt_mean":93.56},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=GNAZ","jax_strain_url":"https://www.jax.org/strain/search?query=GNAZ"},"sequence":{"accession":"P19086","fasta_url":"https://rest.uniprot.org/uniprotkb/P19086.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/P19086/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/P19086"}},"corpus_meta":[{"pmid":"21398039","id":"PMC_21398039","title":"Influence from genetic variability on opioid use for cancer pain: a European genetic association study of 2294 cancer pain patients.","date":"2011","source":"Pain","url":"https://pubmed.ncbi.nlm.nih.gov/21398039","citation_count":151,"is_preprint":false},{"pmid":"2902634","id":"PMC_2902634","title":"Chromosomal localization of genes encoding guanine nucleotide-binding protein subunits in mouse and human.","date":"1988","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/2902634","citation_count":118,"is_preprint":false},{"pmid":"28421530","id":"PMC_28421530","title":"Time-of-Day Dependent Neuronal Injury After Ischemic Stroke: Implication of Circadian Clock Transcriptional Factor Bmal1 and Survival Kinase AKT.","date":"2017","source":"Molecular neurobiology","url":"https://pubmed.ncbi.nlm.nih.gov/28421530","citation_count":80,"is_preprint":false},{"pmid":"17239488","id":"PMC_17239488","title":"Multiple genes and factors associated with bipolar disorder converge on growth factor and stress activated kinase pathways controlling translation initiation: implications for oligodendrocyte viability.","date":"2007","source":"Neurochemistry international","url":"https://pubmed.ncbi.nlm.nih.gov/17239488","citation_count":72,"is_preprint":false},{"pmid":"9599735","id":"PMC_9599735","title":"Total genome scan analysis in a single extended family for primary nocturnal enuresis: evidence for a new locus (ENUR3) for primary nocturnal enuresis on chromosome 22q11.","date":"1998","source":"European urology","url":"https://pubmed.ncbi.nlm.nih.gov/9599735","citation_count":44,"is_preprint":false},{"pmid":"34049561","id":"PMC_34049561","title":"Identification of circRNA-miRNA-mRNA networks contributes to explore underlying pathogenesis and therapy strategy of gastric cancer.","date":"2021","source":"Journal of translational medicine","url":"https://pubmed.ncbi.nlm.nih.gov/34049561","citation_count":41,"is_preprint":false},{"pmid":"25535338","id":"PMC_25535338","title":"Gas1 is a receptor for sonic hedgehog to repel enteric axons.","date":"2014","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/25535338","citation_count":40,"is_preprint":false},{"pmid":"28813466","id":"PMC_28813466","title":"Comprehensive comparison of neonate and adult human platelet transcriptomes.","date":"2017","source":"PloS one","url":"https://pubmed.ncbi.nlm.nih.gov/28813466","citation_count":40,"is_preprint":false},{"pmid":"35879796","id":"PMC_35879796","title":"RGS1 and related genes as potential targets for immunotherapy in cervical cancer: computational biology and experimental validation.","date":"2022","source":"Journal of translational medicine","url":"https://pubmed.ncbi.nlm.nih.gov/35879796","citation_count":32,"is_preprint":false},{"pmid":"22065927","id":"PMC_22065927","title":"The human Müller cell line MIO-M1 expresses opsins.","date":"2011","source":"Molecular vision","url":"https://pubmed.ncbi.nlm.nih.gov/22065927","citation_count":30,"is_preprint":false},{"pmid":"20424519","id":"PMC_20424519","title":"Novel somatic mutations in heterotrimeric G proteins in melanoma.","date":"2010","source":"Cancer biology & therapy","url":"https://pubmed.ncbi.nlm.nih.gov/20424519","citation_count":19,"is_preprint":false},{"pmid":"30218739","id":"PMC_30218739","title":"Differentially expressed gene (DEG) based protein-protein interaction (PPI) network identifies a spectrum of gene interactome, transcriptome and correlated miRNA in nondisjunction Down syndrome.","date":"2018","source":"International journal of biological macromolecules","url":"https://pubmed.ncbi.nlm.nih.gov/30218739","citation_count":18,"is_preprint":false},{"pmid":"18474292","id":"PMC_18474292","title":"BCR expression is decreased in meningiomas showing loss of heterozygosity of 22q within a new minimal deletion region.","date":"2008","source":"Cancer genetics and cytogenetics","url":"https://pubmed.ncbi.nlm.nih.gov/18474292","citation_count":18,"is_preprint":false},{"pmid":"10402497","id":"PMC_10402497","title":"Analysis of GNAZ gene polymorphism in bipolar affective disorder.","date":"1999","source":"American journal of medical genetics","url":"https://pubmed.ncbi.nlm.nih.gov/10402497","citation_count":16,"is_preprint":false},{"pmid":"33960436","id":"PMC_33960436","title":"Screening of tumor grade-related mRNAs and lncRNAs for Esophagus Squamous Cell Carcinoma.","date":"2021","source":"Journal of clinical laboratory analysis","url":"https://pubmed.ncbi.nlm.nih.gov/33960436","citation_count":16,"is_preprint":false},{"pmid":"10607907","id":"PMC_10607907","title":"Isolation of genes from the rhabdoid tumor deletion region in chromosome band 22q11.2.","date":"2000","source":"Gene","url":"https://pubmed.ncbi.nlm.nih.gov/10607907","citation_count":16,"is_preprint":false},{"pmid":"22997493","id":"PMC_22997493","title":"Activated PTHLH coupling feedback phosphoinositide to G-protein receptor signal-induced cell adhesion network in human hepatocellular carcinoma by systems-theoretic analysis.","date":"2012","source":"TheScientificWorldJournal","url":"https://pubmed.ncbi.nlm.nih.gov/22997493","citation_count":15,"is_preprint":false},{"pmid":"24321455","id":"PMC_24321455","title":"Gαz regulates BDNF-induction of axon growth in cortical neurons.","date":"2013","source":"Molecular and cellular neurosciences","url":"https://pubmed.ncbi.nlm.nih.gov/24321455","citation_count":14,"is_preprint":false},{"pmid":"37095509","id":"PMC_37095509","title":"Blue light exposure collapses the inner blood-retinal barrier by accelerating endothelial CLDN5 degradation through the disturbance of GNAZ and the activation of ADAM17.","date":"2023","source":"Fluids and barriers of the CNS","url":"https://pubmed.ncbi.nlm.nih.gov/37095509","citation_count":13,"is_preprint":false},{"pmid":"29088301","id":"PMC_29088301","title":"Gnaz couples the circadian and dopaminergic system to G protein-mediated signaling in mouse photoreceptors.","date":"2017","source":"PloS one","url":"https://pubmed.ncbi.nlm.nih.gov/29088301","citation_count":12,"is_preprint":false},{"pmid":"8973916","id":"PMC_8973916","title":"G protein alpha subunit multigene family in the Japanese puffer fish Fugu rubripes: PCR from a compact vertebrate genome.","date":"1996","source":"Genome research","url":"https://pubmed.ncbi.nlm.nih.gov/8973916","citation_count":12,"is_preprint":false},{"pmid":"30627818","id":"PMC_30627818","title":"Downregulation of genes outside the deleted region in individuals with 22q11.2 deletion syndrome.","date":"2019","source":"Human genetics","url":"https://pubmed.ncbi.nlm.nih.gov/30627818","citation_count":9,"is_preprint":false},{"pmid":"8975005","id":"PMC_8975005","title":"GNAZ in human fetal cochlea: expression, localization, and potential role in inner ear function.","date":"1995","source":"Hearing research","url":"https://pubmed.ncbi.nlm.nih.gov/8975005","citation_count":7,"is_preprint":false},{"pmid":"9653653","id":"PMC_9653653","title":"Fine genetic and comparative mapping of the deafness mutation Ames waltzer on mouse chromosome 10.","date":"1998","source":"Genomics","url":"https://pubmed.ncbi.nlm.nih.gov/9653653","citation_count":6,"is_preprint":false},{"pmid":"16264227","id":"PMC_16264227","title":"Differentially expressed genes associated with hepatitis B virus HBx and MHBs protein function in hepatocellular carcinoma.","date":"2006","source":"Methods in molecular biology (Clifton, N.J.)","url":"https://pubmed.ncbi.nlm.nih.gov/16264227","citation_count":5,"is_preprint":false},{"pmid":"30788840","id":"PMC_30788840","title":"Expression of GNAZ, encoding the Gαz protein, predicts survival in mantle cell lymphoma.","date":"2019","source":"British journal of haematology","url":"https://pubmed.ncbi.nlm.nih.gov/30788840","citation_count":4,"is_preprint":false},{"pmid":"38077646","id":"PMC_38077646","title":"Long non-coding RNA CDKN2B-AS1 promotes hepatocellular carcinoma progression via E2F transcription factor 1/G protein subunit alpha Z axis.","date":"2023","source":"World journal of gastrointestinal oncology","url":"https://pubmed.ncbi.nlm.nih.gov/38077646","citation_count":4,"is_preprint":false},{"pmid":"34913528","id":"PMC_34913528","title":"Concomitant variants in NF1, LZTR1 and GNAZ genes probably contribute to the aggressiveness of plexiform neurofibroma and warrant treatment with MEK inhibitor.","date":"2021","source":"Experimental dermatology","url":"https://pubmed.ncbi.nlm.nih.gov/34913528","citation_count":3,"is_preprint":false},{"pmid":"34768523","id":"PMC_34768523","title":"Differential Expression of the Sphingolipid Pathway Is Associated with Sensitivity to the PP2A Activator FTY720 in Colorectal Cancer Cell Lines.","date":"2021","source":"Journal of clinical medicine","url":"https://pubmed.ncbi.nlm.nih.gov/34768523","citation_count":1,"is_preprint":false},{"pmid":"41306771","id":"PMC_41306771","title":"ATPase Inhibitory Factor 1 Drives Mitochondrial Energy Metabolic Reprogramming to Promote HCC Vasculogenic Mimicry via the ESR1/miR-20a-3p/GNAZ Pathway.","date":"2025","source":"Research (Washington, D.C.)","url":"https://pubmed.ncbi.nlm.nih.gov/41306771","citation_count":0,"is_preprint":false},{"pmid":"41025546","id":"PMC_41025546","title":"LAG3 as a Tumor Suppressor and Immune Regulator in Cervical Cancer: From Functional Validation to Therapeutic Strategy.","date":"2025","source":"Cancer medicine","url":"https://pubmed.ncbi.nlm.nih.gov/41025546","citation_count":0,"is_preprint":false},{"pmid":"40894772","id":"PMC_40894772","title":"Free fatty acid receptor 4 agonists stimulate insulin secretion via different mechanisms in mouse versus human islets.","date":"2025","source":"bioRxiv : the preprint server for biology","url":"https://pubmed.ncbi.nlm.nih.gov/40894772","citation_count":0,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":17556,"output_tokens":2475,"usd":0.044896},"stage2":{"model":"claude-opus-4-6","input_tokens":5817,"output_tokens":2559,"usd":0.13959},"total_usd":0.184486,"stage1_batch_id":"msgbatch_01DzrsgVgYngY1hvM3DU1yF2","stage2_batch_id":"msgbatch_01KA9b7iRzKFdhoBUT7vCvSe","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 1988,\n      \"finding\": \"GNAZ was chromosomally localized to human chromosome 22 by hybridization of cDNA clones with DNA from human-mouse somatic cell hybrids, establishing its genomic position within the G protein alpha-subunit gene family.\",\n      \"method\": \"Somatic cell hybrid panel + cDNA hybridization\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — direct genomic mapping with molecular probes, foundational study replicated by subsequent mapping papers\",\n      \"pmids\": [\"2902634\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1995,\n      \"finding\": \"GNAZ is expressed in human fetal cochlea, specifically localized by in situ hybridization and immunohistochemistry, suggesting a role in maintaining ionic balance of perilymphatic and endolymphatic cochlear fluids.\",\n      \"method\": \"Northern blot, tissue in situ hybridization, immunohistochemistry\",\n      \"journal\": \"Hearing research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — direct localization by multiple methods but functional role is inferred, single lab\",\n      \"pmids\": [\"8975005\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"Gαz (GNAZ) is localized to axonal growth cones in cortical neurons and inhibits BDNF-stimulated axon growth, establishing an endogenous role in regulating neurotrophin signaling in the CNS.\",\n      \"method\": \"Gz knockout mouse cortical neurons (ex vivo and cultured), immunolocalization, axon growth assays\",\n      \"journal\": \"Molecular and cellular neurosciences\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — clean KO with defined cellular phenotype (axon growth), direct localization, multiple experimental approaches\",\n      \"pmids\": [\"24321455\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"Gnaz is expressed in enteric axons and couples Smoothened (Smo) signaling downstream of Sonic Hedgehog (Shh) to mediate axon repulsion; knockdown or dominant-negative inhibition of Gnaz dampens the axon-repulsive response to Shh, and Gnaz mutant intestines contain centrally projected enteric axons.\",\n      \"method\": \"Enteric neuron knockdown, dominant-negative inhibition, Gnaz mutant mouse intestines, in vitro axon turning assay\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — genetic KO with specific anatomical phenotype plus in vitro functional assay and dominant-negative, multiple orthogonal methods\",\n      \"pmids\": [\"25535338\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"Gnaz is expressed in photoreceptors and its protein product Gαz shows a daily rhythm in subcellular localization; Gnaz expression rhythm is dependent on the circadian Clock gene and dopamine D4 receptors, linking the circadian clockwork via dopamine to G protein-mediated signaling in retinal photoreceptors.\",\n      \"method\": \"Microdissected photoreceptors, whole retina preparations, Clock and D4 receptor knockout mice, subcellular fractionation/immunolocalization, constant darkness experiments\",\n      \"journal\": \"PloS one\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — multiple genetic models (Clock KO, D4R KO, db/db), direct subcellular localization experiments, replicated across conditions\",\n      \"pmids\": [\"29088301\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"GNAZ sequesters ADAM17 under normal conditions; blue light illumination disrupts the GNAZ-ADAM17 interaction, allowing ADAM17 to hyperactivate and cleave claudin-5 (CLDN5), collapsing the inner blood-retinal barrier. GNAZ knockdown phenocopies blue light exposure by causing ADAM17 hyperactivation, CLDN5 downregulation, and paracellular permeability.\",\n      \"method\": \"GNAZ knockdown (in vitro and in vivo), pharmacological and genetic ADAM17 inhibition, co-immunoprecipitation (GNAZ-ADAM17 interaction), tight junction permeability assays, electroretinogram, mouse blue-light exposure model\",\n      \"journal\": \"Fluids and barriers of the CNS\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — reciprocal interaction demonstrated, KD phenotype with specific molecular readout, in vitro and in vivo validation, multiple orthogonal methods\",\n      \"pmids\": [\"37095509\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"In mouse pancreatic islets, FFAR4 activation stimulates insulin secretion indirectly through Gαz-coupled inhibition of somatostatin (SST) secretion from δ cells; Gnaz deletion prevents FFAR4 agonist inhibition of SST secretion and abolishes the reduction in Ca2+ transients in δ cells, but does not prevent direct insulin potentiation in human islets.\",\n      \"method\": \"Gnaz knockout mouse islets, δ-cell ablation, SST-deficient mice, purified β and δ cells, Ca2+ imaging, insulin/SST secretion assays\",\n      \"journal\": \"bioRxiv\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 — clean KO with specific secretory phenotype, Ca2+ dynamics, multiple genetic controls and cell-type-specific dissection\",\n      \"pmids\": [\"40894772\"],\n      \"is_preprint\": true\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"GNAZ promotes hepatocellular carcinoma vasculogenic mimicry by phosphorylating components of the ERK pathway; it is a direct target of miR-20a-3p, and its expression is transcriptionally regulated by E2F1 via the CDKN2B-AS1/E2F1/GNAZ axis.\",\n      \"method\": \"Dual-luciferase reporter assay, chromatin immunoprecipitation, lentivirus-mediated miR-20a-3p overexpression, transcriptome sequencing, in vitro tube formation and in vivo VM/metastasis assays\",\n      \"journal\": \"Research (Washington, D.C.)\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — luciferase and ChIP validate transcriptional regulation; ERK phosphorylation link is mechanistic but from single lab\",\n      \"pmids\": [\"41306771\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"CDKN2B-AS1 lncRNA recruits E2F1 to the GNAZ promoter region to facilitate GNAZ transcription, promoting HCC cell proliferation and survival; RNA immunoprecipitation confirmed CDKN2B-AS1-E2F1 interaction and ChIP verified E2F1 binding to the GNAZ promoter.\",\n      \"method\": \"RNA immunoprecipitation, chromatin immunoprecipitation, luciferase reporter assay, CDKN2B-AS1 knockdown with GNAZ/E2F1 rescue experiments\",\n      \"journal\": \"World journal of gastrointestinal oncology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — RIP and ChIP validate interaction; single lab, convergent with IF1/ESR1/miR-20a-3p study\",\n      \"pmids\": [\"38077646\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"A somatic variant in GNAZ found in a plexiform neurofibroma leads to increased ERK1/2 activation compared to wild-type GNAZ, suggesting GNAZ can activate the MAPK pathway when mutated.\",\n      \"method\": \"Whole-exome sequencing, ERK1/2 phosphorylation assay in cells expressing mutant vs. wild-type GNAZ\",\n      \"journal\": \"Experimental dermatology\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 — single case study, single signaling readout, limited controls\",\n      \"pmids\": [\"34913528\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"GNAZ encodes Gαz, a pertussis toxin-insensitive inhibitory G protein alpha subunit that localizes to axonal growth cones, photoreceptor subcellular compartments, and retinal endothelial cells, where it inhibits BDNF-stimulated axon growth, couples circadian/dopaminergic input to photoreceptor G protein signaling via D4 receptors, sequesters ADAM17 to protect the inner blood-retinal barrier, mediates Sonic Hedgehog-driven enteric axon repulsion through Smoothened, and in pancreatic δ cells couples FFAR4 activation to inhibition of somatostatin secretion, thereby indirectly stimulating insulin release; transcriptionally, GNAZ is regulated by a CDKN2B-AS1/E2F1 axis and is post-transcriptionally suppressed by miR-20a-3p, with mutant forms activating ERK/MAPK signaling.\"\n}\n```","stage2_raw":"```json\n{\n  \"mechanistic_narrative\": \"GNAZ encodes Gαz, a pertussis toxin-insensitive inhibitory heterotrimeric G protein alpha subunit that transduces signals from diverse receptors to regulate axon guidance, photoreceptor physiology, barrier integrity, and endocrine secretion. Gαz localizes to axonal growth cones where it inhibits BDNF-stimulated axon growth and couples Smoothened signaling downstream of Sonic Hedgehog to mediate enteric axon repulsion [PMID:24321455, PMID:25535338]. In the retina, Gαz undergoes circadian- and dopamine D4 receptor-dependent rhythmic redistribution in photoreceptors and sequesters the sheddase ADAM17 in retinal endothelial cells, preventing claudin-5 cleavage and preserving inner blood-retinal barrier integrity [PMID:29088301, PMID:37095509]. GNAZ transcription is driven by a CDKN2B-AS1/E2F1 axis and post-transcriptionally suppressed by miR-20a-3p, and in hepatocellular carcinoma its overexpression activates ERK/MAPK signaling to promote vasculogenic mimicry [PMID:38077646, PMID:41306771].\",\n  \"teleology\": [\n    {\n      \"year\": 1988,\n      \"claim\": \"The chromosomal position of GNAZ was unknown among the expanding G protein alpha-subunit family; somatic cell hybrid mapping placed it on human chromosome 22, anchoring it genomically.\",\n      \"evidence\": \"cDNA hybridization to human-mouse somatic cell hybrid DNA panel\",\n      \"pmids\": [\"2902634\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"No functional data at this stage\", \"Expression pattern undefined\"]\n    },\n    {\n      \"year\": 1995,\n      \"claim\": \"Whether GNAZ was expressed outside the brain was unclear; detection of Gαz mRNA and protein in human fetal cochlea expanded the tissue repertoire and suggested involvement in ionic homeostasis of cochlear fluids.\",\n      \"evidence\": \"Northern blot, in situ hybridization, and immunohistochemistry on human fetal cochlea\",\n      \"pmids\": [\"8975005\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Functional role in cochlea remains inferred from localization only\", \"No loss-of-function data in this tissue\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"It was not known whether Gαz had a cell-autonomous role in CNS axon development; Gnaz knockout cortical neurons showed enhanced BDNF-stimulated axon growth, establishing Gαz as an endogenous brake on neurotrophin-driven axon extension.\",\n      \"evidence\": \"Gnaz knockout mouse cortical neurons, immunolocalization to growth cones, axon length assays\",\n      \"pmids\": [\"24321455\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Receptor upstream of Gαz in cortical neurons not identified\", \"Downstream effector linking Gαz to growth cone cytoskeleton unknown\"]\n    },\n    {\n      \"year\": 2014,\n      \"claim\": \"How Sonic Hedgehog repels enteric axons was unresolved; this work showed that Gαz couples the Smoothened receptor to an axon-repulsive output, and Gnaz-mutant intestines exhibit misprojected enteric axons.\",\n      \"evidence\": \"Gnaz knockdown and dominant-negative inhibition in enteric neurons, axon turning assay, Gnaz mutant mouse intestines\",\n      \"pmids\": [\"25535338\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Effector between Gαz and cytoskeletal rearrangement in enteric growth cones uncharacterized\", \"Whether Gαz-Smo coupling is direct or requires an intermediate is unresolved\"]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"How circadian and dopaminergic signals converge on photoreceptor G protein signaling was unknown; Gαz was shown to undergo daily rhythmic subcellular redistribution in photoreceptors dependent on Clock and dopamine D4 receptors.\",\n      \"evidence\": \"Microdissected photoreceptors from Clock KO and D4R KO mice, subcellular fractionation, constant-darkness paradigm\",\n      \"pmids\": [\"29088301\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Downstream effector of Gαz in photoreceptor signaling not identified\", \"Mechanism driving Gαz subcellular translocation unclear\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Whether GNAZ variants could activate oncogenic signaling was untested; a somatic GNAZ variant in a plexiform neurofibroma increased ERK1/2 phosphorylation relative to wild-type, linking mutant Gαz to MAPK pathway activation.\",\n      \"evidence\": \"Whole-exome sequencing of tumor, ERK phosphorylation assay comparing mutant and wild-type GNAZ in cell lines\",\n      \"pmids\": [\"34913528\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"Single case with limited controls\", \"Mechanism by which mutant Gαz activates ERK unknown\", \"Not independently confirmed in additional tumors\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"The mechanism protecting the inner blood-retinal barrier from sheddase activity was unclear; Gαz was shown to sequester ADAM17, and disruption of this interaction (by blue light or GNAZ knockdown) hyperactivates ADAM17, cleaves claudin-5, and increases paracellular permeability.\",\n      \"evidence\": \"Co-immunoprecipitation of GNAZ-ADAM17, GNAZ knockdown in vitro and in vivo, tight junction permeability assays, mouse blue-light model\",\n      \"pmids\": [\"37095509\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Structural basis of the GNAZ-ADAM17 interaction unknown\", \"Whether Gαz GTPase activity is required for ADAM17 sequestration untested\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Transcriptional control of GNAZ was undefined; the CDKN2B-AS1 lncRNA was found to recruit E2F1 to the GNAZ promoter, driving transcription, and miR-20a-3p was identified as a direct post-transcriptional suppressor, with GNAZ overexpression promoting ERK-dependent vasculogenic mimicry in hepatocellular carcinoma.\",\n      \"evidence\": \"RNA immunoprecipitation, ChIP, dual-luciferase reporters, miR-20a-3p overexpression, in vivo VM/metastasis assays in HCC models\",\n      \"pmids\": [\"38077646\", \"41306771\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Findings from a single group; independent replication needed\", \"Whether ERK activation by wild-type Gαz in HCC uses the same mechanism as the tumor-derived mutant is unknown\", \"Role of GTPase cycle in ERK activation not dissected\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"How FFAR4 agonists stimulate insulin secretion was incompletely understood; Gnaz deletion in mouse δ cells abolished FFAR4-mediated inhibition of somatostatin secretion and the associated Ca²⁺ transient reduction, demonstrating Gαz as the coupling G protein in δ cells for paracrine regulation of insulin release.\",\n      \"evidence\": \"(preprint) Gnaz knockout mouse islets, δ-cell ablation, SST-deficient mice, Ca²⁺ imaging, insulin/SST secretion assays\",\n      \"pmids\": [\"40894772\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Preprint; not yet peer-reviewed\", \"Mechanism differs between mouse and human islets — human δ-cell coupling not fully resolved\", \"Direct Gαz–FFAR4 physical interaction not demonstrated\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"The immediate downstream effectors of Gαz in most contexts (growth cones, photoreceptors, enteric axons) remain unidentified, and no structural model of Gαz interaction with ADAM17 or Smoothened exists.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No effector identified for Gαz in axon growth or retinal signaling\", \"Structural basis of GNAZ-ADAM17 and GNAZ-Smo coupling unknown\", \"In vivo relevance of GNAZ-ERK axis in human cancer not established\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0003924\", \"supporting_discovery_ids\": [2, 3, 4, 6]},\n      {\"term_id\": \"GO:0060089\", \"supporting_discovery_ids\": [3, 4, 6]},\n      {\"term_id\": \"GO:0140313\", \"supporting_discovery_ids\": [5]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005886\", \"supporting_discovery_ids\": [2, 4, 5]},\n      {\"term_id\": \"GO:0005829\", \"supporting_discovery_ids\": [4]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [2, 3, 4, 5, 6, 7, 9]},\n      {\"term_id\": \"R-HSA-1266738\", \"supporting_discovery_ids\": [3]},\n      {\"term_id\": \"R-HSA-112316\", \"supporting_discovery_ids\": [2, 3]},\n      {\"term_id\": \"R-HSA-9709957\", \"supporting_discovery_ids\": [4]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\n      \"ADAM17\",\n      \"SMO\",\n      \"FFAR4\",\n      \"E2F1\",\n      \"DRD4\"\n    ],\n    \"other_free_text\": []\n  }\n}\n```"}