{"gene":"RABL3","run_date":"2026-06-10T06:43:36","timeline":{"discoveries":[{"year":2019,"finding":"RABL3 interacts with RAP1GDS1 (SmgGDS), a chaperone regulating prenylation of RAS GTPases, and the truncated mutant RABL3 protein accelerates KRAS prenylation; this interaction was identified by transcriptomic and mass spectrometry approaches, and the truncated mutant RABL3 requires RAS proteins to promote cell proliferation.","method":"Mass spectrometry (co-IP/pulldown), transcriptomic analysis, functional cell proliferation assays in heterozygous rabl3 mutant zebrafish model","journal":"Nature genetics","confidence":"High","confidence_rationale":"Tier 2 / Moderate — multiple orthogonal methods (MS-based interaction, transcriptomics, in vivo zebrafish model, functional rescue assays) in a single rigorous study","pmids":["31406347"],"is_preprint":false},{"year":2020,"finding":"RABL3 forms a homodimer in solution via interactions between effector binding surfaces on each subunit, with monomers adopting a typical small G protein fold; crystal structure revealed the xm hypomorphic deletion causes a compensatory alteration in switch I adopting a β-strand configuration, permitting homodimer formation but likely dysregulating effector binding due to conformational changes in the switch I–interswitch–switch II module.","method":"Crystallography (X-ray), biophysical studies (solution-phase dimerization assays)","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"High","confidence_rationale":"Tier 1 / Strong — crystal structure plus biophysical characterization with functional validation via in vivo mouse genetics","pmids":["32220963"],"is_preprint":false},{"year":2020,"finding":"RABL3 is essential for lymphoid development: homozygous knockout of mouse Rabl3 is embryonic lethal; a viable hypomorphic allele (xm, in-frame 4-amino-acid deletion in interswitch region) causes profound defects in lymphopoiesis, with deficiencies of B cells, T cells, and NK cells, impaired cytolytic activity, and elevated MCMV titers in spleen.","method":"Mouse knockout and hypomorphic allele generation (ENU mutagenesis), flow cytometry, viral infection assays","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"High","confidence_rationale":"Tier 2 / Strong — in vivo genetic loss-of-function with defined cellular phenotypes across multiple immune lineages and functional assays","pmids":["32220963"],"is_preprint":false},{"year":2020,"finding":"RABL3 (but not RABL3xm) strongly associates with and stabilizes GPR89 (putatively an ion channel or GPCR), and an ENU-induced mutation in Gpr89 (explorer allele) phenocopies Rabl3xm, placing GPR89 as a downstream effector of RABL3 in lymphoid development.","method":"Co-immunoprecipitation/association assay, genetic epistasis (ENU-induced Gpr89 mutant phenocopying Rabl3xm in mice)","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — reciprocal genetic epistasis plus protein association assay in single study","pmids":["32220963"],"is_preprint":false},{"year":2010,"finding":"RABL3 overexpression enhances cell proliferation, inhibits apoptosis, promotes paclitaxel resistance, and increases cell motility in human cancer cell lines; silencing RABL3 reverses these effects; mechanistically, RABL3 function is associated with FAK phosphorylation at Tyr 397/576/577 in HeLa and MDA-MB-231 cells.","method":"Overexpression (pcDNA3.1 plasmid), siRNA knockdown, Western blot (FAK phosphorylation), proliferation and motility assays","journal":"Oncology reports","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — single lab, multiple cell lines and assays, Western blot for FAK phosphorylation as mechanism","pmids":["20596630"],"is_preprint":false},{"year":2021,"finding":"Knockdown of RABL3 suppresses proliferation, migration, and invasion of oral squamous cell carcinoma cells and inhibits tumorigenesis in vivo; mechanistically, RABL3 regulates activation of the FAK/AKT signaling pathway, and inhibition of FAK reverses the effects of RABL3 overexpression.","method":"shRNA knockdown, overexpression, FAK inhibitor rescue, in vivo xenograft, Western blot","journal":"Journal of bioenergetics and biomembranes","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — single lab, multiple orthogonal approaches (KD, OE, pharmacological inhibition, in vivo) converging on FAK/AKT pathway","pmids":["33438143"],"is_preprint":false}],"current_model":"RABL3 is a small GTPase that homodimerizes via its effector-binding surfaces (established by crystal structure), interacts with RAP1GDS1/SmgGDS to regulate KRAS prenylation, acts as an effector upstream of GPR89 in lymphoid development, and promotes cell proliferation, survival, and motility at least partly through FAK/AKT pathway activation; loss-of-function in mice causes embryonic lethality (homozygous) or profound lymphopenia with impaired cytolytic immunity (hypomorphic), while gain-of-function or truncating mutations dysregulate RAS activity and confer cancer susceptibility."},"narrative":{"mechanistic_narrative":"RABL3 is a small G-protein-fold GTPase that couples RAS prenylation control to cell proliferation, immune development, and cancer susceptibility [PMID:31406347, PMID:32220963]. It interacts with the prenylation chaperone RAP1GDS1/SmgGDS, and a truncating mutant accelerates KRAS prenylation in a RAS-dependent manner to drive proliferation, linking RABL3 to dysregulated RAS activity [PMID:31406347]. Structurally, RABL3 homodimerizes through the effector-binding surfaces of each monomer; a hypomorphic in-frame deletion forces switch I into a β-strand configuration that still permits dimerization but distorts the switch I–interswitch–switch II effector module [PMID:32220963]. RABL3 is essential for development and immunity: homozygous loss is embryonic lethal in mice, while the hypomorphic allele causes profound lymphopenia spanning B, T, and NK lineages with impaired cytolytic activity, and it acts genetically upstream of its effector GPR89, which it binds and stabilizes [PMID:32220963]. In human cancer cells RABL3 promotes proliferation, survival, motility, and chemoresistance, acting at least in part through activation of the FAK/AKT signaling pathway [PMID:20596630, PMID:33438143]. The catalytic GTPase cycle of RABL3 and the precise mechanism linking its effector module to RAS prenylation have not been characterized in the available corpus.","teleology":[{"year":2010,"claim":"Established that RABL3 is a functional driver of cancer cell phenotypes rather than a passive marker, by showing its expression level controls proliferation, survival, drug resistance, and motility.","evidence":"Overexpression and siRNA knockdown with proliferation/motility assays and FAK phosphorylation Western blots in HeLa and MDA-MB-231 cells","pmids":["20596630"],"confidence":"Medium","gaps":["Single-lab correlation of FAK phosphorylation without direct biochemical link","Does not establish how a small GTPase engages FAK","No in vivo validation in this study"]},{"year":2019,"claim":"Connected RABL3 to RAS biology by identifying its physical interaction with the prenylation chaperone SmgGDS and showing a truncating mutant accelerates KRAS prenylation, defining a mechanism for cancer susceptibility.","evidence":"Mass spectrometry interaction mapping, transcriptomics, and proliferation/rescue assays in a heterozygous rabl3 mutant zebrafish model","pmids":["31406347"],"confidence":"High","gaps":["Mechanism by which RABL3 modulates SmgGDS chaperone activity not resolved","Whether wild-type RABL3 normally restrains prenylation unclear","Direct enzymatic role of RABL3 GTPase cycle not defined"]},{"year":2020,"claim":"Defined the structural basis of RABL3 function by solving its crystal structure, revealing effector-surface-mediated homodimerization and explaining how the hypomorphic deletion remodels the switch I effector module.","evidence":"X-ray crystallography and solution-phase dimerization assays with in vivo mouse genetic validation","pmids":["32220963"],"confidence":"High","gaps":["Functional role of homodimerization in vivo not directly tested","Nucleotide-binding/hydrolysis state in the structure not detailed here","How conformational change alters specific effector binding not measured"]},{"year":2020,"claim":"Demonstrated RABL3 is essential for development and immunity, establishing physiological loss-of-function phenotypes distinct from its oncogenic gain-of-function role.","evidence":"Mouse knockout (embryonic lethal) and ENU hypomorphic allele with flow cytometry across lineages and MCMV infection assays","pmids":["32220963"],"confidence":"High","gaps":["Cellular/molecular cause of embryonic lethality unknown","Whether lymphoid defect reflects altered RAS prenylation untested","Cell-intrinsic vs extrinsic origin of lymphopenia not resolved"]},{"year":2020,"claim":"Placed GPR89 downstream of RABL3 in lymphoid development by showing RABL3 binds and stabilizes GPR89 and that a Gpr89 mutant phenocopies the Rabl3 hypomorph.","evidence":"Co-immunoprecipitation/association assay and reciprocal genetic epistasis with an ENU-induced Gpr89 mutant in mice","pmids":["32220963"],"confidence":"Medium","gaps":["Molecular consequence of GPR89 stabilization unknown","Whether GPR89 acts as a canonical GTPase effector untested","Single-study association without reciprocal biochemical validation"]},{"year":2021,"claim":"Reinforced FAK signaling as a functional output of RABL3 by showing pharmacological FAK inhibition reverses RABL3-driven tumor phenotypes through the FAK/AKT axis.","evidence":"shRNA knockdown, overexpression, FAK inhibitor rescue, and xenograft assays in oral squamous cell carcinoma cells","pmids":["33438143"],"confidence":"Medium","gaps":["Direct molecular link between RABL3 and FAK activation not defined","Relationship between FAK/AKT output and the RAS-prenylation mechanism unclear","Single-lab, single-cancer-type validation"]},{"year":null,"claim":"Whether RABL3 functions as a classical nucleotide-cycling GTPase, and how its SmgGDS/RAS-prenylation activity, GPR89 effector axis, and FAK/AKT output are mechanistically unified, remains unresolved.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No characterization of RABL3 GTP binding/hydrolysis or GEF/GAP regulation","No mechanism connecting RAS prenylation control to FAK/AKT signaling","Whether the GPR89 and RAS-prenylation arms are independent or convergent unknown"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0003924","term_label":"GTPase activity","supporting_discovery_ids":[1]},{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[0,3]}],"localization":[],"pathway":[{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[4,5]},{"term_id":"R-HSA-168256","term_label":"Immune System","supporting_discovery_ids":[2,3]}],"complexes":[],"partners":["RAP1GDS1","GPR89","KRAS"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q5HYI8","full_name":"Rab-like protein 3","aliases":[],"length_aa":236,"mass_kda":26.4,"function":"Small GTPase required for KRAS signaling regulation and modulation of cell proliferation (PubMed:31406347). Regulator of KRAS prenylation, and probably prenylation of other small GTPases (PubMed:31406347). Required for lymphocyte development and function (By similarity). Not required for myeloid cell development (By similarity). Interacts with Rab11 to promote ciliary vesicle formation at the mother centriole, thereby regulating early ciliogenesis. The GTP-binding capacity of RABL3 is essential for ciliogenesis (PubMed:36052645)","subcellular_location":"Cytoplasm, cytoskeleton, microtubule organizing center, centrosome; Golgi apparatus","url":"https://www.uniprot.org/uniprotkb/Q5HYI8/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/RABL3","classification":"Not Classified","n_dependent_lines":14,"n_total_lines":1208,"dependency_fraction":0.011589403973509934},"opencell":{"profiled":true,"resolved_as":"","ensg_id":"ENSG00000144840","cell_line_id":"CID000452","localizations":[{"compartment":"vesicles","grade":3},{"compartment":"er","grade":1}],"interactors":[{"gene":"TMED10","stoichiometry":0.2},{"gene":"TMED2","stoichiometry":0.2},{"gene":"VAMP4","stoichiometry":0.2}],"url":"https://opencell.sf.czbiohub.org/target/CID000452","total_profiled":1310},"omim":[{"mim_id":"618680","title":"PANCREATIC CANCER, SUSCEPTIBILITY TO, 5; PNCA5","url":"https://www.omim.org/entry/618680"},{"mim_id":"618542","title":"RAB, MEMBER OF RAS ONCOGENE FAMILY-LIKE 3; RABL3","url":"https://www.omim.org/entry/618542"},{"mim_id":"616709","title":"ALPHA-1,4-N-ACETYLGLUCOSAMINYLTRANSFERASE; A4GNT","url":"https://www.omim.org/entry/616709"},{"mim_id":"260350","title":"PANCREATIC CANCER","url":"https://www.omim.org/entry/260350"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Approved","locations":[{"location":"Endoplasmic reticulum","reliability":"Approved"}],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in all","driving_tissues":[],"url":"https://www.proteinatlas.org/search/RABL3"},"hgnc":{"alias_symbol":["MGC23920"],"prev_symbol":[]},"alphafold":{"accession":"Q5HYI8","domains":[{"cath_id":"3.40.50.300","chopping":"5-208","consensus_level":"high","plddt":86.8749,"start":5,"end":208}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q5HYI8","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q5HYI8-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q5HYI8-F1-predicted_aligned_error_v6.png","plddt_mean":80.69},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=RABL3","jax_strain_url":"https://www.jax.org/strain/search?query=RABL3"},"sequence":{"accession":"Q5HYI8","fasta_url":"https://rest.uniprot.org/uniprotkb/Q5HYI8.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q5HYI8/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q5HYI8"}},"corpus_meta":[{"pmid":"31406347","id":"PMC_31406347","title":"Mutations in RABL3 alter KRAS prenylation and are associated with hereditary pancreatic cancer.","date":"2019","source":"Nature genetics","url":"https://pubmed.ncbi.nlm.nih.gov/31406347","citation_count":49,"is_preprint":false},{"pmid":"34631898","id":"PMC_34631898","title":"circCOL1A1 Promotes the Progression of Gastric Cancer Cells through Sponging miR-145 to Enhance RABL3 Expression.","date":"2021","source":"Journal of immunology research","url":"https://pubmed.ncbi.nlm.nih.gov/34631898","citation_count":14,"is_preprint":false},{"pmid":"32220963","id":"PMC_32220963","title":"Genetic and structural studies of RABL3 reveal an essential role in lymphoid development and function.","date":"2020","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/32220963","citation_count":13,"is_preprint":false},{"pmid":"20596630","id":"PMC_20596630","title":"Evaluation of the novel gene Rabl3 in the regulation of proliferation and motility in human cancer cells.","date":"2010","source":"Oncology reports","url":"https://pubmed.ncbi.nlm.nih.gov/20596630","citation_count":11,"is_preprint":false},{"pmid":"33015775","id":"PMC_33015775","title":"Long non-coding RNA LINC00858 promotes cells proliferation and invasion through the miR-153-3p/Rabl3 axis in hepatocellular carcinoma.","date":"2020","source":"European review for medical and pharmacological sciences","url":"https://pubmed.ncbi.nlm.nih.gov/33015775","citation_count":11,"is_preprint":false},{"pmid":"31298353","id":"PMC_31298353","title":"MiR-296-3p may affect the proliferation and migration of non-small cell lung cancer cells via regulating RABL3.","date":"2019","source":"European review for medical and pharmacological sciences","url":"https://pubmed.ncbi.nlm.nih.gov/31298353","citation_count":11,"is_preprint":false},{"pmid":"31748878","id":"PMC_31748878","title":"Identification of GIMAP7 and Rabl3 as Putative Biomarkers for Oral Squamous Cell Carcinoma Through Comparative Proteomic Approach.","date":"2019","source":"Pathology oncology research : POR","url":"https://pubmed.ncbi.nlm.nih.gov/31748878","citation_count":9,"is_preprint":false},{"pmid":"28443498","id":"PMC_28443498","title":"The overexpression of Rabl3 is associated with pathogenesis and clinicopathologic variables in hepatocellular carcinoma.","date":"2017","source":"Tumour biology : the journal of the International Society for Oncodevelopmental Biology and Medicine","url":"https://pubmed.ncbi.nlm.nih.gov/28443498","citation_count":7,"is_preprint":false},{"pmid":"33438143","id":"PMC_33438143","title":"Knockdown of RABL3 suppresses the proliferation and invasion of oral squamous cell carcinoma through inactivating the FAK/AKT pathway.","date":"2021","source":"Journal of bioenergetics and biomembranes","url":"https://pubmed.ncbi.nlm.nih.gov/33438143","citation_count":3,"is_preprint":false},{"pmid":"33724601","id":"PMC_33724601","title":"Germline sequence analysis of RABL3 in a large series of pancreatic ductal adenocarcinoma patients reveals no evidence of deleterious variants.","date":"2021","source":"Genes, chromosomes & cancer","url":"https://pubmed.ncbi.nlm.nih.gov/33724601","citation_count":3,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":7358,"output_tokens":1617,"usd":0.023165,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":8414,"output_tokens":2605,"usd":0.053597,"stage2_stop_reason":"end_turn"},"total_usd":0.076762,"stage1_batch_id":"msgbatch_01CNoDbkChHEkgrJnL7BwtGJ","stage2_batch_id":"msgbatch_016Y4x9E9Wg5VQDANj9quSQD","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2019,\n      \"finding\": \"RABL3 interacts with RAP1GDS1 (SmgGDS), a chaperone regulating prenylation of RAS GTPases, and the truncated mutant RABL3 protein accelerates KRAS prenylation; this interaction was identified by transcriptomic and mass spectrometry approaches, and the truncated mutant RABL3 requires RAS proteins to promote cell proliferation.\",\n      \"method\": \"Mass spectrometry (co-IP/pulldown), transcriptomic analysis, functional cell proliferation assays in heterozygous rabl3 mutant zebrafish model\",\n      \"journal\": \"Nature genetics\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple orthogonal methods (MS-based interaction, transcriptomics, in vivo zebrafish model, functional rescue assays) in a single rigorous study\",\n      \"pmids\": [\"31406347\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"RABL3 forms a homodimer in solution via interactions between effector binding surfaces on each subunit, with monomers adopting a typical small G protein fold; crystal structure revealed the xm hypomorphic deletion causes a compensatory alteration in switch I adopting a β-strand configuration, permitting homodimer formation but likely dysregulating effector binding due to conformational changes in the switch I–interswitch–switch II module.\",\n      \"method\": \"Crystallography (X-ray), biophysical studies (solution-phase dimerization assays)\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — crystal structure plus biophysical characterization with functional validation via in vivo mouse genetics\",\n      \"pmids\": [\"32220963\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"RABL3 is essential for lymphoid development: homozygous knockout of mouse Rabl3 is embryonic lethal; a viable hypomorphic allele (xm, in-frame 4-amino-acid deletion in interswitch region) causes profound defects in lymphopoiesis, with deficiencies of B cells, T cells, and NK cells, impaired cytolytic activity, and elevated MCMV titers in spleen.\",\n      \"method\": \"Mouse knockout and hypomorphic allele generation (ENU mutagenesis), flow cytometry, viral infection assays\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — in vivo genetic loss-of-function with defined cellular phenotypes across multiple immune lineages and functional assays\",\n      \"pmids\": [\"32220963\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"RABL3 (but not RABL3xm) strongly associates with and stabilizes GPR89 (putatively an ion channel or GPCR), and an ENU-induced mutation in Gpr89 (explorer allele) phenocopies Rabl3xm, placing GPR89 as a downstream effector of RABL3 in lymphoid development.\",\n      \"method\": \"Co-immunoprecipitation/association assay, genetic epistasis (ENU-induced Gpr89 mutant phenocopying Rabl3xm in mice)\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — reciprocal genetic epistasis plus protein association assay in single study\",\n      \"pmids\": [\"32220963\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"RABL3 overexpression enhances cell proliferation, inhibits apoptosis, promotes paclitaxel resistance, and increases cell motility in human cancer cell lines; silencing RABL3 reverses these effects; mechanistically, RABL3 function is associated with FAK phosphorylation at Tyr 397/576/577 in HeLa and MDA-MB-231 cells.\",\n      \"method\": \"Overexpression (pcDNA3.1 plasmid), siRNA knockdown, Western blot (FAK phosphorylation), proliferation and motility assays\",\n      \"journal\": \"Oncology reports\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — single lab, multiple cell lines and assays, Western blot for FAK phosphorylation as mechanism\",\n      \"pmids\": [\"20596630\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"Knockdown of RABL3 suppresses proliferation, migration, and invasion of oral squamous cell carcinoma cells and inhibits tumorigenesis in vivo; mechanistically, RABL3 regulates activation of the FAK/AKT signaling pathway, and inhibition of FAK reverses the effects of RABL3 overexpression.\",\n      \"method\": \"shRNA knockdown, overexpression, FAK inhibitor rescue, in vivo xenograft, Western blot\",\n      \"journal\": \"Journal of bioenergetics and biomembranes\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — single lab, multiple orthogonal approaches (KD, OE, pharmacological inhibition, in vivo) converging on FAK/AKT pathway\",\n      \"pmids\": [\"33438143\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"RABL3 is a small GTPase that homodimerizes via its effector-binding surfaces (established by crystal structure), interacts with RAP1GDS1/SmgGDS to regulate KRAS prenylation, acts as an effector upstream of GPR89 in lymphoid development, and promotes cell proliferation, survival, and motility at least partly through FAK/AKT pathway activation; loss-of-function in mice causes embryonic lethality (homozygous) or profound lymphopenia with impaired cytolytic immunity (hypomorphic), while gain-of-function or truncating mutations dysregulate RAS activity and confer cancer susceptibility.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"RABL3 is a small G-protein-fold GTPase that couples RAS prenylation control to cell proliferation, immune development, and cancer susceptibility [#0, #2]. It interacts with the prenylation chaperone RAP1GDS1/SmgGDS, and a truncating mutant accelerates KRAS prenylation in a RAS-dependent manner to drive proliferation, linking RABL3 to dysregulated RAS activity [#0]. Structurally, RABL3 homodimerizes through the effector-binding surfaces of each monomer; a hypomorphic in-frame deletion forces switch I into a β-strand configuration that still permits dimerization but distorts the switch I–interswitch–switch II effector module [#1]. RABL3 is essential for development and immunity: homozygous loss is embryonic lethal in mice, while the hypomorphic allele causes profound lymphopenia spanning B, T, and NK lineages with impaired cytolytic activity, and it acts genetically upstream of its effector GPR89, which it binds and stabilizes [#1, #2, #3]. In human cancer cells RABL3 promotes proliferation, survival, motility, and chemoresistance, acting at least in part through activation of the FAK/AKT signaling pathway [#4, #5]. The catalytic GTPase cycle of RABL3 and the precise mechanism linking its effector module to RAS prenylation have not been characterized in the available corpus.\",\n  \"teleology\": [\n    {\n      \"year\": 2010,\n      \"claim\": \"Established that RABL3 is a functional driver of cancer cell phenotypes rather than a passive marker, by showing its expression level controls proliferation, survival, drug resistance, and motility.\",\n      \"evidence\": \"Overexpression and siRNA knockdown with proliferation/motility assays and FAK phosphorylation Western blots in HeLa and MDA-MB-231 cells\",\n      \"pmids\": [\"20596630\"],\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"\",\n      \"gaps\": [\"Single-lab correlation of FAK phosphorylation without direct biochemical link\", \"Does not establish how a small GTPase engages FAK\", \"No in vivo validation in this study\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Connected RABL3 to RAS biology by identifying its physical interaction with the prenylation chaperone SmgGDS and showing a truncating mutant accelerates KRAS prenylation, defining a mechanism for cancer susceptibility.\",\n      \"evidence\": \"Mass spectrometry interaction mapping, transcriptomics, and proliferation/rescue assays in a heterozygous rabl3 mutant zebrafish model\",\n      \"pmids\": [\"31406347\"],\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"\",\n      \"gaps\": [\"Mechanism by which RABL3 modulates SmgGDS chaperone activity not resolved\", \"Whether wild-type RABL3 normally restrains prenylation unclear\", \"Direct enzymatic role of RABL3 GTPase cycle not defined\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Defined the structural basis of RABL3 function by solving its crystal structure, revealing effector-surface-mediated homodimerization and explaining how the hypomorphic deletion remodels the switch I effector module.\",\n      \"evidence\": \"X-ray crystallography and solution-phase dimerization assays with in vivo mouse genetic validation\",\n      \"pmids\": [\"32220963\"],\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"\",\n      \"gaps\": [\"Functional role of homodimerization in vivo not directly tested\", \"Nucleotide-binding/hydrolysis state in the structure not detailed here\", \"How conformational change alters specific effector binding not measured\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Demonstrated RABL3 is essential for development and immunity, establishing physiological loss-of-function phenotypes distinct from its oncogenic gain-of-function role.\",\n      \"evidence\": \"Mouse knockout (embryonic lethal) and ENU hypomorphic allele with flow cytometry across lineages and MCMV infection assays\",\n      \"pmids\": [\"32220963\"],\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"\",\n      \"gaps\": [\"Cellular/molecular cause of embryonic lethality unknown\", \"Whether lymphoid defect reflects altered RAS prenylation untested\", \"Cell-intrinsic vs extrinsic origin of lymphopenia not resolved\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Placed GPR89 downstream of RABL3 in lymphoid development by showing RABL3 binds and stabilizes GPR89 and that a Gpr89 mutant phenocopies the Rabl3 hypomorph.\",\n      \"evidence\": \"Co-immunoprecipitation/association assay and reciprocal genetic epistasis with an ENU-induced Gpr89 mutant in mice\",\n      \"pmids\": [\"32220963\"],\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"\",\n      \"gaps\": [\"Molecular consequence of GPR89 stabilization unknown\", \"Whether GPR89 acts as a canonical GTPase effector untested\", \"Single-study association without reciprocal biochemical validation\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Reinforced FAK signaling as a functional output of RABL3 by showing pharmacological FAK inhibition reverses RABL3-driven tumor phenotypes through the FAK/AKT axis.\",\n      \"evidence\": \"shRNA knockdown, overexpression, FAK inhibitor rescue, and xenograft assays in oral squamous cell carcinoma cells\",\n      \"pmids\": [\"33438143\"],\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"\",\n      \"gaps\": [\"Direct molecular link between RABL3 and FAK activation not defined\", \"Relationship between FAK/AKT output and the RAS-prenylation mechanism unclear\", \"Single-lab, single-cancer-type validation\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"Whether RABL3 functions as a classical nucleotide-cycling GTPase, and how its SmgGDS/RAS-prenylation activity, GPR89 effector axis, and FAK/AKT output are mechanistically unified, remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"\",\n      \"gaps\": [\"No characterization of RABL3 GTP binding/hydrolysis or GEF/GAP regulation\", \"No mechanism connecting RAS prenylation control to FAK/AKT signaling\", \"Whether the GPR89 and RAS-prenylation arms are independent or convergent unknown\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0003924\", \"supporting_discovery_ids\": [1]},\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [0, 3]}\n    ],\n    \"localization\": [],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [4, 5]},\n      {\"term_id\": \"R-HSA-168256\", \"supporting_discovery_ids\": [2, 3]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\"RAP1GDS1\", \"GPR89\", \"KRAS\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":5,"faith_total":5,"faith_pct":100.0}}