{"gene":"DIRAS2","run_date":"2026-06-09T23:54:42","timeline":{"discoveries":[{"year":2015,"finding":"Di-Ras2 forms a high-affinity complex with SmgGDS protein in rat brain cytosol. SmgGDS does not act as a guanine nucleotide exchange factor for Di-Ras2 but instead tightly associates with Di-Ras2 to reduce its binding affinity for guanine nucleotides. Pulse-chase analysis revealed that Di-Ras2 binds SmgGDS in a C-terminal CAAX motif-dependent manner immediately after synthesis, leading to increased Di-Ras2 stability.","method":"Co-purification from rat brain cytosol, size-exclusion chromatography with recombinant proteins, pulse-chase analysis, CAAX motif-dependent binding assay","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1 / Moderate — in vitro reconstitution with purified recombinant proteins, size-exclusion chromatography, and pulse-chase analysis; multiple orthogonal methods in a single focused study","pmids":["26149690"],"is_preprint":false},{"year":2018,"finding":"DIRAS1 and DIRAS2 re-expression suppressed growth of human and murine ovarian cancer cells by inducing autophagy-mediated cell death. Mechanistically, DIRAS1 and DIRAS2 inhibit AKT1-MTOR and RAS-MAPK signaling pathways and modulate nuclear localization of autophagy-related transcription factors FOXO3/FOXO3A and TFEB.","method":"Re-expression experiments in cancer cell lines, autophagy assays, pathway inhibition assays (AKT1-MTOR, RAS-MAPK), nuclear localization analysis of FOXO3 and TFEB","journal":"Autophagy","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — clean gain-of-function with defined cellular phenotype and pathway placement; multiple signaling readouts but single lab, abstracts do not detail full mechanistic reconstitution","pmids":["29368982"],"is_preprint":false},{"year":2020,"finding":"Di-Ras2 promotes ccRCC cell proliferation, migration and invasion in the absence of pVHL by activating the RAS/MAPK signaling pathway via modulating phosphorylation of downstream effectors. Additionally, Di-Ras2 interacts with the E3 ubiquitin ligase pVHL, which facilitates the ubiquitination and degradation of Di-Ras2.","method":"Gain/loss-of-function experiments in ccRCC cell lines, phosphorylation assays for MAPK effectors, co-immunoprecipitation of Di-Ras2 with pVHL, ubiquitination assays","journal":"Oncogene","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — reciprocal Co-IP, functional KD/OE with pathway readouts, ubiquitination assay; single lab but multiple orthogonal methods","pmids":["32161311"],"is_preprint":false},{"year":2022,"finding":"DIRAS2 inhibits colorectal cancer cell proliferation by blocking NF-κB signaling and inducing G0/G1 arrest. DIRAS2 interacts with 26S proteasome non-ATPase regulatory subunit 2 (PSMD2), which facilitates proteasome-mediated degradation of DIRAS2.","method":"Overexpression and knockdown in CRC cell lines, cell-cycle analysis, NF-κB reporter assays, co-immunoprecipitation with PSMD2, proteasome inhibitor rescue experiments","journal":"International journal of biological sciences","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP with PSMD2, functional overexpression with NF-κB pathway readout and cell-cycle analysis; single lab, multiple methods","pmids":["35173535"],"is_preprint":false},{"year":2024,"finding":"DIRAS2 is a substrate of the CRL5ASB11 E3 ubiquitin ligase complex, which is activated by the neddylation E2 UBE2F. Ube2f deletion blocks ubiquitylation of Diras2, stabilizing it. DIRAS2 in turn suppresses MAPK-c-Myc signaling, and Diras2 deletion largely rescues the growth-suppressive phenotypes induced by Ube2f deletion in the KrasG12D PDAC model.","method":"Genetic deletion of Ube2f in mouse KrasG12D PDAC model, ubiquitylation assays for Diras2 as CRL5ASB11 substrate, epistasis rescue experiments with Diras2 deletion, MAPK-c-Myc signaling pathway analysis","journal":"Developmental cell","confidence":"High","confidence_rationale":"Tier 1–2 / Strong — substrate identification via ubiquitylation assay, genetic epistasis in mouse model, and functional rescue; multiple orthogonal methods including in vivo and in vitro approaches","pmids":["38574733"],"is_preprint":false},{"year":2021,"finding":"Overexpression of DIRAS2 in glioblastoma cell lines sensitizes them to lomustine treatment. Analysis of DNA damage markers suggests DIRAS2 plays a role in p53-dependent response to alkylating chemotherapy. DIRAS2 promoter is regulated by histone modifications (heterochromatinization), and HDAC inhibitor treatment leads to re-expression of DIRAS2.","method":"Overexpression in glioblastoma cell lines, lomustine sensitivity assay, DNA damage marker analysis, histone modification analysis at DIRAS2 promoter, HDAC inhibitor treatment with re-expression assay","journal":"Cancers","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — functional overexpression with chemosensitivity readout, histone modification analysis at promoter, HDAC inhibitor rescue; single lab, multiple methods","pmids":["34680261"],"is_preprint":false},{"year":2025,"finding":"In TNBC, eNAMPT binding to CCR5 activates STAT3, leading to downregulation of DIRAS2 (acting as a tumor suppressor) and an increase in CCL2. This eNAMPT/Ac-STAT3/DIRAS2 axis promotes cancer stemness and macrophage recruitment.","method":"Co-culture system of TAMs and TNBC cells, cytokine arrays, proteomics, CRISPR-Cas9 knockout, STAT3 activation assays, DIRAS2 expression analysis after eNAMPT/CCR5 pathway intervention","journal":"International journal of biological sciences","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — CRISPR-Cas9 functional validation, pathway intervention with STAT3-DIRAS2 readout, co-culture system; single lab","pmids":["40083697"],"is_preprint":false},{"year":2026,"finding":"DIRAS2 modulates neuronal excitation/inhibition balance by inhibiting the ERK/p38 MAPK pathway, thereby suppressing ferroptosis. Knockdown of DIRAS2 exacerbates ferroptosis and increases neuronal hyperexcitability, while overexpression protects against ferroptosis. Ferrostatin-1 (ferroptosis inhibitor) rescues E/I imbalance induced by DIRAS2 knockdown, placing DIRAS2 upstream of ferroptosis via MAPK suppression.","method":"Overexpression and knockdown in vivo (kainic acid epilepsy model) and in vitro, whole-cell patch-clamp recordings, quantitative proteomics, ferroptosis assays, ferrostatin-1 rescue experiment, ERK/p38 MAPK pathway analysis","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"High","confidence_rationale":"Tier 1–2 / Strong — multiple orthogonal methods including electrophysiology, quantitative proteomics, in vivo genetic manipulation, and pharmacological rescue; pathway placement via epistasis","pmids":["41880562"],"is_preprint":false},{"year":2025,"finding":"DIRAS2 promotes cell proliferation in oral leukoplakia via the RAF/MEK/MAPK signaling pathway. Conditional epithelial knockout of DIRAS2 inhibited tongue precancerous lesion progression and decreased expression of MAPK cascade proteins in both knockdown human cells and mouse tongue tissues.","method":"CRISPR/Cas9 and Cre-LoxP conditional knockout mice (K14-Cre x DIRAS2flox/flox), 4NQO-induced precancerous lesion model, DIRAS2 knockdown in human dysplastic oral keratinocytes, MAPK pathway protein expression analysis, cell proliferation assays","journal":"Tissue & cell","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — conditional in vivo KO with defined phenotype, pathway readout in both mouse and human cells; single lab","pmids":["40644959"],"is_preprint":false},{"year":2019,"finding":"Knockdown of Diras2 in murine hippocampal primary cells altered expression of 1,612 genes enriched for biological processes involved in neurodevelopment, indicating that DIRAS2 regulates neurodevelopmental gene expression programs.","method":"shRNA knockdown of Diras2 in hippocampal primary cells, microarray gene expression analysis, qPCR validation of selected genes, ADHD GWAS gene-set enrichment analysis","journal":"Journal of attention disorders","confidence":"Low","confidence_rationale":"Tier 3 / Weak — transcriptomic profiling after KD without direct pathway mechanistic follow-up; single lab, no protein-level mechanism established","pmids":["30623719"],"is_preprint":false}],"current_model":"DIRAS2 is a Ras-related small GTPase that, immediately after synthesis, forms a CAAX-dependent complex with SmgGDS which reduces its guanine nucleotide affinity and increases its stability; it is ubiquitylated and degraded by the CRL5ASB11 E3 ligase complex (activated by neddylation E2 UBE2F) and also by pVHL, and by proteasomal degradation facilitated by PSMD2; when stable and active, DIRAS2 suppresses RAS/MAPK and AKT1-MTOR signaling, modulates nuclear translocation of FOXO3 and TFEB to induce autophagy, blocks NF-κB to cause G0/G1 arrest, and inhibits ferroptosis via ERK/p38 MAPK suppression to regulate neuronal excitation/inhibition balance, collectively acting as a context-dependent tumor suppressor and neuronal regulator."},"narrative":{"mechanistic_narrative":"DIRAS2 is a Ras-related small GTPase that functions as a context-dependent suppressor of mitogenic signaling, controlling cell proliferation, autophagy, and neuronal excitability [PMID:29368982, PMID:38574733, PMID:41880562]. Immediately after synthesis it forms a CAAX motif-dependent, high-affinity complex with SmgGDS that lowers its guanine nucleotide affinity and stabilizes the protein, rather than acting as a conventional nucleotide exchange factor [PMID:26149690]. DIRAS2 abundance is tightly restrained by ubiquitin-dependent turnover: it is a substrate of the UBE2F-activated CRL5ASB11 E3 ligase complex [PMID:38574733], is ubiquitylated and degraded through interaction with the E3 ligase pVHL [PMID:32161311], and is degraded via the proteasome through interaction with the regulatory subunit PSMD2 [PMID:35173535]; its expression is additionally silenced by promoter heterochromatinization and restored by HDAC inhibition [PMID:34680261], and is downregulated by STAT3 activation downstream of the eNAMPT/CCR5 axis [PMID:40083697]. When stabilized and active, DIRAS2 suppresses RAS/MAPK and AKT1-MTOR signaling, driving FOXO3 and TFEB nuclear translocation to induce autophagy-mediated death of cancer cells [PMID:29368982], blocks NF-κB signaling to impose G0/G1 arrest [PMID:35173535], and antagonizes the MAPK-c-Myc growth program [PMID:38574733], collectively acting as a tumor suppressor whose loss promotes proliferation in renal, oral, and other epithelial cancers [PMID:32161311, PMID:40644959]. In neurons, DIRAS2 suppresses ERK/p38 MAPK signaling to inhibit ferroptosis and thereby maintain excitation/inhibition balance [PMID:41880562].","teleology":[{"year":2015,"claim":"Established the first biochemical handle on DIRAS2 regulation by showing its abundance and nucleotide state are controlled by a stable binding partner rather than canonical GEF/GAP cycling.","evidence":"Co-purification from rat brain cytosol, size-exclusion chromatography with recombinant proteins, and pulse-chase CAAX-dependent binding assays","pmids":["26149690"],"confidence":"High","gaps":["Does not establish the active GTP-bound effector functions of DIRAS2","Functional consequence of SmgGDS-mediated stabilization for downstream signaling untested"]},{"year":2018,"claim":"Placed DIRAS2 in cancer biology by demonstrating it acts as a tumor suppressor that inhibits two major proliferative pathways and engages autophagy transcription factors.","evidence":"Re-expression gain-of-function in ovarian cancer cell lines with autophagy assays, AKT1-MTOR/RAS-MAPK pathway readouts, and FOXO3/TFEB nuclear localization analysis","pmids":["29368982"],"confidence":"Medium","gaps":["Direct biochemical link between DIRAS2 and pathway components not reconstituted","Whether DIRAS2 acts on FOXO3/TFEB directly or via MAPK/AKT suppression unresolved"]},{"year":2020,"claim":"Identified pVHL as both an E3 ligase that degrades DIRAS2 and a context determinant, revealing DIRAS2 can switch to a proliferation-promoting RAS/MAPK activator when VHL is lost.","evidence":"Gain/loss-of-function in ccRCC cell lines, MAPK phosphorylation assays, reciprocal Co-IP with pVHL, and ubiquitination assays","pmids":["32161311"],"confidence":"Medium","gaps":["Mechanism of the tumor-suppressor-to-oncogene context switch not defined","Direct ubiquitin transfer by pVHL to DIRAS2 lysines not mapped"]},{"year":2022,"claim":"Extended DIRAS2 growth suppression to NF-κB-driven cell-cycle control and identified PSMD2-coupled proteasomal degradation as a turnover route.","evidence":"Overexpression/knockdown in CRC cell lines, cell-cycle analysis, NF-κB reporter assays, Co-IP with PSMD2, and proteasome inhibitor rescue","pmids":["35173535"],"confidence":"Medium","gaps":["How DIRAS2 mechanistically blocks NF-κB not defined","Whether PSMD2 binding is direct or bridged by an E3 ligase unclear"]},{"year":2024,"claim":"Defined a specific E3 ligase pathway for DIRAS2 turnover and demonstrated in vivo, via genetic epistasis, that DIRAS2 stabilization mediates growth suppression.","evidence":"Ube2f deletion in a KrasG12D mouse PDAC model, ubiquitylation assays identifying DIRAS2 as a CRL5ASB11 substrate, Diras2-deletion rescue epistasis, and MAPK-c-Myc analysis","pmids":["38574733"],"confidence":"High","gaps":["ASB11 substrate-recognition determinants on DIRAS2 not mapped","Relationship between CRL5ASB11, pVHL, and PSMD2 degradation routes not integrated"]},{"year":2021,"claim":"Connected DIRAS2 epigenetic silencing to chemoresistance, showing promoter heterochromatinization restrains DIRAS2 and HDAC inhibition restores it.","evidence":"Overexpression in glioblastoma lines with lomustine sensitivity and DNA-damage marker assays, promoter histone modification analysis, and HDAC inhibitor re-expression","pmids":["34680261"],"confidence":"Medium","gaps":["Direct role of DIRAS2 in p53-dependent damage response not established","Specific histone marks and writers/erasers at the promoter not identified"]},{"year":2025,"claim":"Identified a signaling axis that suppresses DIRAS2 expression, linking tumor microenvironment cytokine signaling to loss of its tumor-suppressor function.","evidence":"TAM/TNBC co-culture, cytokine arrays, proteomics, CRISPR-Cas9 knockout, and STAT3 activation/DIRAS2 expression assays after eNAMPT/CCR5 intervention","pmids":["40083697"],"confidence":"Medium","gaps":["Whether STAT3 directly represses the DIRAS2 promoter not shown","Downstream effectors of DIRAS2 loss in stemness/macrophage recruitment not dissected"]},{"year":2025,"claim":"Provided in vivo genetic evidence that DIRAS2 drives epithelial proliferation through the RAF/MEK/MAPK cascade in precancerous lesions.","evidence":"Conditional epithelial knockout mice (K14-Cre x DIRAS2flox/flox) in a 4NQO precancer model, human dysplastic keratinocyte knockdown, and MAPK protein readouts","pmids":["40644959"],"confidence":"Medium","gaps":["Reconciliation of pro-proliferative MAPK activation here versus MAPK suppression elsewhere unresolved","Direct biochemical engagement of RAF/MEK by DIRAS2 not shown"]},{"year":2026,"claim":"Established a neuronal function for DIRAS2, placing it upstream of ferroptosis via ERK/p38 MAPK suppression to control excitation/inhibition balance.","evidence":"In vivo and in vitro overexpression/knockdown in a kainic acid epilepsy model, whole-cell patch-clamp, quantitative proteomics, ferroptosis assays, and ferrostatin-1 epistasis rescue","pmids":["41880562"],"confidence":"High","gaps":["Molecular mechanism by which DIRAS2 inhibits ERK/p38 not defined","Link between SmgGDS-regulated nucleotide state and neuronal MAPK suppression untested"]},{"year":2019,"claim":"Suggested a broader neurodevelopmental transcriptional role for DIRAS2, linking it to ADHD genetics.","evidence":"shRNA knockdown in murine hippocampal primary cells with microarray profiling, qPCR validation, and ADHD GWAS gene-set enrichment","pmids":["30623719"],"confidence":"Low","gaps":["Transcriptomic profiling without protein-level mechanistic follow-up","Direct targets and signaling intermediaries between DIRAS2 and the altered genes unknown"]},{"year":null,"claim":"It remains unresolved how DIRAS2 toggles between tumor-suppressive MAPK inhibition and proliferation-promoting MAPK activation across tissue contexts, and what GTP-loaded effectors transmit its signal.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No direct effector of GTP-bound DIRAS2 identified","Context determinants of opposite MAPK outputs not mechanistically defined","Integration of multiple degradation pathways (CRL5ASB11, pVHL, PSMD2) not unified"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0003924","term_label":"GTPase activity","supporting_discovery_ids":[0]},{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[1,3,7]}],"localization":[{"term_id":"GO:0005829","term_label":"cytosol","supporting_discovery_ids":[0]}],"pathway":[{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[1,2,4,7]},{"term_id":"R-HSA-9612973","term_label":"Autophagy","supporting_discovery_ids":[1]},{"term_id":"R-HSA-5357801","term_label":"Programmed Cell Death","supporting_discovery_ids":[7]},{"term_id":"R-HSA-392499","term_label":"Metabolism of proteins","supporting_discovery_ids":[2,3,4]}],"complexes":["CRL5ASB11 E3 ubiquitin ligase complex (substrate)"],"partners":["SMGGDS","VHL","PSMD2","UBE2F"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q96HU8","full_name":"GTP-binding protein Di-Ras2","aliases":["Distinct subgroup of the Ras family member 2"],"length_aa":199,"mass_kda":22.5,"function":"Displays low GTPase activity and exists predominantly in the GTP-bound form","subcellular_location":"Cell membrane","url":"https://www.uniprot.org/uniprotkb/Q96HU8/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/DIRAS2","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/DIRAS2","total_profiled":1310},"omim":[{"mim_id":"607863","title":"DIRAS FAMILY, GTP-BINDING RAS-LIKE PROTEIN 2; DIRAS2","url":"https://www.omim.org/entry/607863"},{"mim_id":"607862","title":"DIRAS FAMILY, GTP-BINDING RAS-LIKE PROTEIN 1; DIRAS1","url":"https://www.omim.org/entry/607862"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"","locations":[],"tissue_specificity":"Tissue enriched","tissue_distribution":"Detected in some","driving_tissues":[{"tissue":"brain","ntpm":152.2}],"url":"https://www.proteinatlas.org/search/DIRAS2"},"hgnc":{"alias_symbol":["Di-Ras2","DKFZp761C07121"],"prev_symbol":[]},"alphafold":{"accession":"Q96HU8","domains":[{"cath_id":"3.40.50.300","chopping":"7-193","consensus_level":"high","plddt":91.1794,"start":7,"end":193}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q96HU8","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q96HU8-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q96HU8-F1-predicted_aligned_error_v6.png","plddt_mean":88.81},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=DIRAS2","jax_strain_url":"https://www.jax.org/strain/search?query=DIRAS2"},"sequence":{"accession":"Q96HU8","fasta_url":"https://rest.uniprot.org/uniprotkb/Q96HU8.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q96HU8/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q96HU8"}},"corpus_meta":[{"pmid":"29368982","id":"PMC_29368982","title":"RAS-related GTPases DIRAS1 and DIRAS2 induce autophagic cancer cell death and are required for autophagy in murine ovarian cancer cells.","date":"2018","source":"Autophagy","url":"https://pubmed.ncbi.nlm.nih.gov/29368982","citation_count":47,"is_preprint":false},{"pmid":"21750579","id":"PMC_21750579","title":"DIRAS2 is associated with adult ADHD, related traits, and co-morbid disorders.","date":"2011","source":"Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology","url":"https://pubmed.ncbi.nlm.nih.gov/21750579","citation_count":33,"is_preprint":false},{"pmid":"38574733","id":"PMC_38574733","title":"The UBE2F-CRL5ASB11-DIRAS2 axis is an oncogene and tumor suppressor cascade in pancreatic cancer cells.","date":"2024","source":"Developmental cell","url":"https://pubmed.ncbi.nlm.nih.gov/38574733","citation_count":17,"is_preprint":false},{"pmid":"35173535","id":"PMC_35173535","title":"Diverse Ras-related GTPase DIRAS2, downregulated by PSMD2 in a proteasome-mediated way, inhibits colorectal cancer proliferation by blocking NF-κB signaling.","date":"2022","source":"International journal of biological sciences","url":"https://pubmed.ncbi.nlm.nih.gov/35173535","citation_count":14,"is_preprint":false},{"pmid":"26149690","id":"PMC_26149690","title":"Di-Ras2 Protein Forms a Complex with SmgGDS Protein in Brain Cytosol in Order to Be in a Low Affinity State for Guanine Nucleotides.","date":"2015","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/26149690","citation_count":14,"is_preprint":false},{"pmid":"32161311","id":"PMC_32161311","title":"Di-Ras2 promotes renal cell carcinoma formation by activating the mitogen-activated protein kinase pathway in the absence of von Hippel-Lindau protein.","date":"2020","source":"Oncogene","url":"https://pubmed.ncbi.nlm.nih.gov/32161311","citation_count":12,"is_preprint":false},{"pmid":"27364329","id":"PMC_27364329","title":"Functional Impact of An ADHD-Associated DIRAS2 Promoter Polymorphism.","date":"2016","source":"Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology","url":"https://pubmed.ncbi.nlm.nih.gov/27364329","citation_count":10,"is_preprint":false},{"pmid":"40083697","id":"PMC_40083697","title":"eNAMPT/Ac-STAT3/DIRAS2 Axis Promotes Development and Cancer Stemness in Triple-Negative Breast Cancer by Enhancing Cytokine Crosstalk Between Tumor-Associated Macrophages and Cancer Cells.","date":"2025","source":"International journal of biological sciences","url":"https://pubmed.ncbi.nlm.nih.gov/40083697","citation_count":9,"is_preprint":false},{"pmid":"34680261","id":"PMC_34680261","title":"Frequent Epigenetic Inactivation of DIRAS-1 and DIRAS-2 Contributes to Chemo-Resistance in Gliomas.","date":"2021","source":"Cancers","url":"https://pubmed.ncbi.nlm.nih.gov/34680261","citation_count":8,"is_preprint":false},{"pmid":"29488099","id":"PMC_29488099","title":"Expression of the ADHD candidate gene Diras2 in the brain.","date":"2018","source":"Journal of neural transmission (Vienna, Austria : 1996)","url":"https://pubmed.ncbi.nlm.nih.gov/29488099","citation_count":8,"is_preprint":false},{"pmid":"30623719","id":"PMC_30623719","title":"Knockdown of the ADHD Candidate Gene Diras2 in Murine Hippocampal Primary Cells.","date":"2019","source":"Journal of attention disorders","url":"https://pubmed.ncbi.nlm.nih.gov/30623719","citation_count":7,"is_preprint":false},{"pmid":"41880562","id":"PMC_41880562","title":"DIRAS2 modulates MAPK pathway-mediated ferroptosis to regulate excitation/inhibition balance and seizure susceptibility.","date":"2026","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/41880562","citation_count":0,"is_preprint":false},{"pmid":"40644959","id":"PMC_40644959","title":"The small GTP-binding Ras-like protein DIRAS2 promotes cell proliferation in oral leukoplakia via the RAF/MEK/MAPK pathway.","date":"2025","source":"Tissue & cell","url":"https://pubmed.ncbi.nlm.nih.gov/40644959","citation_count":0,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":8879,"output_tokens":2984,"usd":0.035699,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":10417,"output_tokens":3857,"usd":0.074255,"stage2_stop_reason":"end_turn"},"total_usd":0.109954,"stage1_batch_id":"msgbatch_01AsR7g8dGTEiEw9U83bJeWn","stage2_batch_id":"msgbatch_01YV5ZyxtFNUZEjxRcpd9jzb","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2015,\n      \"finding\": \"Di-Ras2 forms a high-affinity complex with SmgGDS protein in rat brain cytosol. SmgGDS does not act as a guanine nucleotide exchange factor for Di-Ras2 but instead tightly associates with Di-Ras2 to reduce its binding affinity for guanine nucleotides. Pulse-chase analysis revealed that Di-Ras2 binds SmgGDS in a C-terminal CAAX motif-dependent manner immediately after synthesis, leading to increased Di-Ras2 stability.\",\n      \"method\": \"Co-purification from rat brain cytosol, size-exclusion chromatography with recombinant proteins, pulse-chase analysis, CAAX motif-dependent binding assay\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — in vitro reconstitution with purified recombinant proteins, size-exclusion chromatography, and pulse-chase analysis; multiple orthogonal methods in a single focused study\",\n      \"pmids\": [\"26149690\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"DIRAS1 and DIRAS2 re-expression suppressed growth of human and murine ovarian cancer cells by inducing autophagy-mediated cell death. Mechanistically, DIRAS1 and DIRAS2 inhibit AKT1-MTOR and RAS-MAPK signaling pathways and modulate nuclear localization of autophagy-related transcription factors FOXO3/FOXO3A and TFEB.\",\n      \"method\": \"Re-expression experiments in cancer cell lines, autophagy assays, pathway inhibition assays (AKT1-MTOR, RAS-MAPK), nuclear localization analysis of FOXO3 and TFEB\",\n      \"journal\": \"Autophagy\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — clean gain-of-function with defined cellular phenotype and pathway placement; multiple signaling readouts but single lab, abstracts do not detail full mechanistic reconstitution\",\n      \"pmids\": [\"29368982\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"Di-Ras2 promotes ccRCC cell proliferation, migration and invasion in the absence of pVHL by activating the RAS/MAPK signaling pathway via modulating phosphorylation of downstream effectors. Additionally, Di-Ras2 interacts with the E3 ubiquitin ligase pVHL, which facilitates the ubiquitination and degradation of Di-Ras2.\",\n      \"method\": \"Gain/loss-of-function experiments in ccRCC cell lines, phosphorylation assays for MAPK effectors, co-immunoprecipitation of Di-Ras2 with pVHL, ubiquitination assays\",\n      \"journal\": \"Oncogene\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — reciprocal Co-IP, functional KD/OE with pathway readouts, ubiquitination assay; single lab but multiple orthogonal methods\",\n      \"pmids\": [\"32161311\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"DIRAS2 inhibits colorectal cancer cell proliferation by blocking NF-κB signaling and inducing G0/G1 arrest. DIRAS2 interacts with 26S proteasome non-ATPase regulatory subunit 2 (PSMD2), which facilitates proteasome-mediated degradation of DIRAS2.\",\n      \"method\": \"Overexpression and knockdown in CRC cell lines, cell-cycle analysis, NF-κB reporter assays, co-immunoprecipitation with PSMD2, proteasome inhibitor rescue experiments\",\n      \"journal\": \"International journal of biological sciences\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP with PSMD2, functional overexpression with NF-κB pathway readout and cell-cycle analysis; single lab, multiple methods\",\n      \"pmids\": [\"35173535\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"DIRAS2 is a substrate of the CRL5ASB11 E3 ubiquitin ligase complex, which is activated by the neddylation E2 UBE2F. Ube2f deletion blocks ubiquitylation of Diras2, stabilizing it. DIRAS2 in turn suppresses MAPK-c-Myc signaling, and Diras2 deletion largely rescues the growth-suppressive phenotypes induced by Ube2f deletion in the KrasG12D PDAC model.\",\n      \"method\": \"Genetic deletion of Ube2f in mouse KrasG12D PDAC model, ubiquitylation assays for Diras2 as CRL5ASB11 substrate, epistasis rescue experiments with Diras2 deletion, MAPK-c-Myc signaling pathway analysis\",\n      \"journal\": \"Developmental cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 / Strong — substrate identification via ubiquitylation assay, genetic epistasis in mouse model, and functional rescue; multiple orthogonal methods including in vivo and in vitro approaches\",\n      \"pmids\": [\"38574733\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"Overexpression of DIRAS2 in glioblastoma cell lines sensitizes them to lomustine treatment. Analysis of DNA damage markers suggests DIRAS2 plays a role in p53-dependent response to alkylating chemotherapy. DIRAS2 promoter is regulated by histone modifications (heterochromatinization), and HDAC inhibitor treatment leads to re-expression of DIRAS2.\",\n      \"method\": \"Overexpression in glioblastoma cell lines, lomustine sensitivity assay, DNA damage marker analysis, histone modification analysis at DIRAS2 promoter, HDAC inhibitor treatment with re-expression assay\",\n      \"journal\": \"Cancers\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — functional overexpression with chemosensitivity readout, histone modification analysis at promoter, HDAC inhibitor rescue; single lab, multiple methods\",\n      \"pmids\": [\"34680261\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"In TNBC, eNAMPT binding to CCR5 activates STAT3, leading to downregulation of DIRAS2 (acting as a tumor suppressor) and an increase in CCL2. This eNAMPT/Ac-STAT3/DIRAS2 axis promotes cancer stemness and macrophage recruitment.\",\n      \"method\": \"Co-culture system of TAMs and TNBC cells, cytokine arrays, proteomics, CRISPR-Cas9 knockout, STAT3 activation assays, DIRAS2 expression analysis after eNAMPT/CCR5 pathway intervention\",\n      \"journal\": \"International journal of biological sciences\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — CRISPR-Cas9 functional validation, pathway intervention with STAT3-DIRAS2 readout, co-culture system; single lab\",\n      \"pmids\": [\"40083697\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"DIRAS2 modulates neuronal excitation/inhibition balance by inhibiting the ERK/p38 MAPK pathway, thereby suppressing ferroptosis. Knockdown of DIRAS2 exacerbates ferroptosis and increases neuronal hyperexcitability, while overexpression protects against ferroptosis. Ferrostatin-1 (ferroptosis inhibitor) rescues E/I imbalance induced by DIRAS2 knockdown, placing DIRAS2 upstream of ferroptosis via MAPK suppression.\",\n      \"method\": \"Overexpression and knockdown in vivo (kainic acid epilepsy model) and in vitro, whole-cell patch-clamp recordings, quantitative proteomics, ferroptosis assays, ferrostatin-1 rescue experiment, ERK/p38 MAPK pathway analysis\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 / Strong — multiple orthogonal methods including electrophysiology, quantitative proteomics, in vivo genetic manipulation, and pharmacological rescue; pathway placement via epistasis\",\n      \"pmids\": [\"41880562\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"DIRAS2 promotes cell proliferation in oral leukoplakia via the RAF/MEK/MAPK signaling pathway. Conditional epithelial knockout of DIRAS2 inhibited tongue precancerous lesion progression and decreased expression of MAPK cascade proteins in both knockdown human cells and mouse tongue tissues.\",\n      \"method\": \"CRISPR/Cas9 and Cre-LoxP conditional knockout mice (K14-Cre x DIRAS2flox/flox), 4NQO-induced precancerous lesion model, DIRAS2 knockdown in human dysplastic oral keratinocytes, MAPK pathway protein expression analysis, cell proliferation assays\",\n      \"journal\": \"Tissue & cell\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — conditional in vivo KO with defined phenotype, pathway readout in both mouse and human cells; single lab\",\n      \"pmids\": [\"40644959\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"Knockdown of Diras2 in murine hippocampal primary cells altered expression of 1,612 genes enriched for biological processes involved in neurodevelopment, indicating that DIRAS2 regulates neurodevelopmental gene expression programs.\",\n      \"method\": \"shRNA knockdown of Diras2 in hippocampal primary cells, microarray gene expression analysis, qPCR validation of selected genes, ADHD GWAS gene-set enrichment analysis\",\n      \"journal\": \"Journal of attention disorders\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — transcriptomic profiling after KD without direct pathway mechanistic follow-up; single lab, no protein-level mechanism established\",\n      \"pmids\": [\"30623719\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"DIRAS2 is a Ras-related small GTPase that, immediately after synthesis, forms a CAAX-dependent complex with SmgGDS which reduces its guanine nucleotide affinity and increases its stability; it is ubiquitylated and degraded by the CRL5ASB11 E3 ligase complex (activated by neddylation E2 UBE2F) and also by pVHL, and by proteasomal degradation facilitated by PSMD2; when stable and active, DIRAS2 suppresses RAS/MAPK and AKT1-MTOR signaling, modulates nuclear translocation of FOXO3 and TFEB to induce autophagy, blocks NF-κB to cause G0/G1 arrest, and inhibits ferroptosis via ERK/p38 MAPK suppression to regulate neuronal excitation/inhibition balance, collectively acting as a context-dependent tumor suppressor and neuronal regulator.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"DIRAS2 is a Ras-related small GTPase that functions as a context-dependent suppressor of mitogenic signaling, controlling cell proliferation, autophagy, and neuronal excitability [#1, #4, #7]. Immediately after synthesis it forms a CAAX motif-dependent, high-affinity complex with SmgGDS that lowers its guanine nucleotide affinity and stabilizes the protein, rather than acting as a conventional nucleotide exchange factor [#0]. DIRAS2 abundance is tightly restrained by ubiquitin-dependent turnover: it is a substrate of the UBE2F-activated CRL5ASB11 E3 ligase complex [#4], is ubiquitylated and degraded through interaction with the E3 ligase pVHL [#2], and is degraded via the proteasome through interaction with the regulatory subunit PSMD2 [#3]; its expression is additionally silenced by promoter heterochromatinization and restored by HDAC inhibition [#5], and is downregulated by STAT3 activation downstream of the eNAMPT/CCR5 axis [#6]. When stabilized and active, DIRAS2 suppresses RAS/MAPK and AKT1-MTOR signaling, driving FOXO3 and TFEB nuclear translocation to induce autophagy-mediated death of cancer cells [#1], blocks NF-\\u03baB signaling to impose G0/G1 arrest [#3], and antagonizes the MAPK-c-Myc growth program [#4], collectively acting as a tumor suppressor whose loss promotes proliferation in renal, oral, and other epithelial cancers [#2, #8]. In neurons, DIRAS2 suppresses ERK/p38 MAPK signaling to inhibit ferroptosis and thereby maintain excitation/inhibition balance [#7].\",\n  \"teleology\": [\n    {\n      \"year\": 2015,\n      \"claim\": \"Established the first biochemical handle on DIRAS2 regulation by showing its abundance and nucleotide state are controlled by a stable binding partner rather than canonical GEF/GAP cycling.\",\n      \"evidence\": \"Co-purification from rat brain cytosol, size-exclusion chromatography with recombinant proteins, and pulse-chase CAAX-dependent binding assays\",\n      \"pmids\": [\"26149690\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Does not establish the active GTP-bound effector functions of DIRAS2\", \"Functional consequence of SmgGDS-mediated stabilization for downstream signaling untested\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Placed DIRAS2 in cancer biology by demonstrating it acts as a tumor suppressor that inhibits two major proliferative pathways and engages autophagy transcription factors.\",\n      \"evidence\": \"Re-expression gain-of-function in ovarian cancer cell lines with autophagy assays, AKT1-MTOR/RAS-MAPK pathway readouts, and FOXO3/TFEB nuclear localization analysis\",\n      \"pmids\": [\"29368982\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct biochemical link between DIRAS2 and pathway components not reconstituted\", \"Whether DIRAS2 acts on FOXO3/TFEB directly or via MAPK/AKT suppression unresolved\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Identified pVHL as both an E3 ligase that degrades DIRAS2 and a context determinant, revealing DIRAS2 can switch to a proliferation-promoting RAS/MAPK activator when VHL is lost.\",\n      \"evidence\": \"Gain/loss-of-function in ccRCC cell lines, MAPK phosphorylation assays, reciprocal Co-IP with pVHL, and ubiquitination assays\",\n      \"pmids\": [\"32161311\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Mechanism of the tumor-suppressor-to-oncogene context switch not defined\", \"Direct ubiquitin transfer by pVHL to DIRAS2 lysines not mapped\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Extended DIRAS2 growth suppression to NF-\\u03baB-driven cell-cycle control and identified PSMD2-coupled proteasomal degradation as a turnover route.\",\n      \"evidence\": \"Overexpression/knockdown in CRC cell lines, cell-cycle analysis, NF-\\u03baB reporter assays, Co-IP with PSMD2, and proteasome inhibitor rescue\",\n      \"pmids\": [\"35173535\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"How DIRAS2 mechanistically blocks NF-\\u03baB not defined\", \"Whether PSMD2 binding is direct or bridged by an E3 ligase unclear\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Defined a specific E3 ligase pathway for DIRAS2 turnover and demonstrated in vivo, via genetic epistasis, that DIRAS2 stabilization mediates growth suppression.\",\n      \"evidence\": \"Ube2f deletion in a KrasG12D mouse PDAC model, ubiquitylation assays identifying DIRAS2 as a CRL5ASB11 substrate, Diras2-deletion rescue epistasis, and MAPK-c-Myc analysis\",\n      \"pmids\": [\"38574733\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"ASB11 substrate-recognition determinants on DIRAS2 not mapped\", \"Relationship between CRL5ASB11, pVHL, and PSMD2 degradation routes not integrated\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Connected DIRAS2 epigenetic silencing to chemoresistance, showing promoter heterochromatinization restrains DIRAS2 and HDAC inhibition restores it.\",\n      \"evidence\": \"Overexpression in glioblastoma lines with lomustine sensitivity and DNA-damage marker assays, promoter histone modification analysis, and HDAC inhibitor re-expression\",\n      \"pmids\": [\"34680261\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct role of DIRAS2 in p53-dependent damage response not established\", \"Specific histone marks and writers/erasers at the promoter not identified\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Identified a signaling axis that suppresses DIRAS2 expression, linking tumor microenvironment cytokine signaling to loss of its tumor-suppressor function.\",\n      \"evidence\": \"TAM/TNBC co-culture, cytokine arrays, proteomics, CRISPR-Cas9 knockout, and STAT3 activation/DIRAS2 expression assays after eNAMPT/CCR5 intervention\",\n      \"pmids\": [\"40083697\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether STAT3 directly represses the DIRAS2 promoter not shown\", \"Downstream effectors of DIRAS2 loss in stemness/macrophage recruitment not dissected\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Provided in vivo genetic evidence that DIRAS2 drives epithelial proliferation through the RAF/MEK/MAPK cascade in precancerous lesions.\",\n      \"evidence\": \"Conditional epithelial knockout mice (K14-Cre x DIRAS2flox/flox) in a 4NQO precancer model, human dysplastic keratinocyte knockdown, and MAPK protein readouts\",\n      \"pmids\": [\"40644959\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Reconciliation of pro-proliferative MAPK activation here versus MAPK suppression elsewhere unresolved\", \"Direct biochemical engagement of RAF/MEK by DIRAS2 not shown\"]\n    },\n    {\n      \"year\": 2026,\n      \"claim\": \"Established a neuronal function for DIRAS2, placing it upstream of ferroptosis via ERK/p38 MAPK suppression to control excitation/inhibition balance.\",\n      \"evidence\": \"In vivo and in vitro overexpression/knockdown in a kainic acid epilepsy model, whole-cell patch-clamp, quantitative proteomics, ferroptosis assays, and ferrostatin-1 epistasis rescue\",\n      \"pmids\": [\"41880562\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Molecular mechanism by which DIRAS2 inhibits ERK/p38 not defined\", \"Link between SmgGDS-regulated nucleotide state and neuronal MAPK suppression untested\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Suggested a broader neurodevelopmental transcriptional role for DIRAS2, linking it to ADHD genetics.\",\n      \"evidence\": \"shRNA knockdown in murine hippocampal primary cells with microarray profiling, qPCR validation, and ADHD GWAS gene-set enrichment\",\n      \"pmids\": [\"30623719\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"Transcriptomic profiling without protein-level mechanistic follow-up\", \"Direct targets and signaling intermediaries between DIRAS2 and the altered genes unknown\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"It remains unresolved how DIRAS2 toggles between tumor-suppressive MAPK inhibition and proliferation-promoting MAPK activation across tissue contexts, and what GTP-loaded effectors transmit its signal.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No direct effector of GTP-bound DIRAS2 identified\", \"Context determinants of opposite MAPK outputs not mechanistically defined\", \"Integration of multiple degradation pathways (CRL5ASB11, pVHL, PSMD2) not unified\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0003924\", \"supporting_discovery_ids\": [0]},\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [1, 3, 7]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005829\", \"supporting_discovery_ids\": [0]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [1, 2, 4, 7]},\n      {\"term_id\": \"R-HSA-9612973\", \"supporting_discovery_ids\": [1]},\n      {\"term_id\": \"R-HSA-5357801\", \"supporting_discovery_ids\": [7]},\n      {\"term_id\": \"R-HSA-392499\", \"supporting_discovery_ids\": [2, 3, 4]}\n    ],\n    \"complexes\": [\"CRL5ASB11 E3 ubiquitin ligase complex (substrate)\"],\n    \"partners\": [\"SmgGDS\", \"VHL\", \"PSMD2\", \"UBE2F\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":4,"faith_total":5,"faith_pct":80.0}}