{"uniprot":"Q6ZN32","gene":"ETV3L","name":"ETS translocation variant 3-like protein","organism":"Homo sapiens (Human)","status":"dark","length":361,"sequence":"MHCSCLAEGIPANPGNWISGLAFPDWAYKAESSPGSRQIQLWHFILELLQKEEFRHVIAWQQGEYGEFVIKDPDEVARLWGRRKCKPQMNYDKLSRALRYYYNKRILHKTKGKRFTYKFNFSKLIVVNYPLWEVRAPPSPHLLLGAPALCRPALVPVGVQSELLHSMLFAHQAMVEQLTGQQTPRGPPETSGDKKGSSSSVYRLGSAPGPCRLGLCCHLGSVQGELPGVASFTPPLPPPLPSNWTCLSGPFLPPLPSEQQLPGAFKPDILLPGPRSLPGAWHFPGLPLLAGLGQGAGERLWLLSLRPEGLEVKPAPMMEAKGGLDPREVFCPETRRLKTGEESLTSPNLENLKAVWPLDPP","function_summary":"A nuclear transcriptional regulator that uses a winged-helix DNA-binding core to recognize purine-rich regulatory elements and assemble repressive transcriptional complexes. By recruiting co-regulatory machinery in the nucleoplasm, it dampens RNA polymerase II–driven transcription at select loci, thereby shaping developmental gene-expression programs tied to embryogenesis and somatic sex determination.","plain_language":"ETV3L has barely been studied. The model's best guess: A nuclear transcriptional regulator that uses a winged-helix DNA-binding core to recognize purine-rich regulatory elements and assemble repressive transcriptional complexes. By recruiting co-regulatory machinery in the nucleoplasm, it dampens RNA polymerase II–driven transcription at select loci, thereby shaping developmental gene-expression programs tied to embryogenesis and somatic sex determination.","uniprot_summary":"Probable transcription factor. May be involved in embryogenesis and somatic sex determination.","go_terms":{"molecular_function":[{"id":"GO:0005515","label":"protein binding"}],"biological_process":[{"id":"GO:0000122","label":"negative regulation of transcription by RNA polymerase II"}],"cellular_component":[{"id":"GO:0005654","label":"nucleoplasm"}]},"interpro":[{"id":"IPR036388","name":"Winged helix-like DNA-binding domain superfamily","type":"homologous_superfamily","start":24,"end":132},{"id":"IPR036390","name":"Winged helix DNA-binding domain superfamily","type":"homologous_superfamily","start":37,"end":142},{"id":"IPR000418","name":"Ets domain","type":"domain","start":38,"end":124},{"id":"IPR046328","name":"ETS family","type":"family","start":23,"end":126}],"reasoning":"I begin with the InterPro architecture. Two overlapping superfamily signatures dominate the core of the protein: IPR036388 (Winged helix-like DNA-binding domain superfamily, residues 24–132) and IPR036390 (Winged helix DNA-binding domain superfamily, residues 37–142). Nested within these is IPR000418 (Ets domain, residues 38–124), the hallmark DNA-recognition module of ETS transcription factors. The overall family assignment IPR046328 (ETS family, residues 23–126) reinforces that this polypeptide is an ETS-class regulator. The ordered layout—broad winged-helix superfamily coverage that encapsulates a sharply defined Ets domain—creates a rigid DNA-binding core that recognizes purine-rich motifs and positions the protein on chromatin. This architecture causes sequence-specific DNA binding and transcriptional control rather than enzymatic catalysis.\n\nFrom this domain logic, the primary molecular function is DNA-binding transcription factor activity. The Ets domain confers high-affinity, sequence-specific DNA binding and provides surfaces for assembling regulatory complexes, which necessitates multivalent protein binding. This supports GO:0005515 protein binding and further implies DNA-binding transcription factor activity that modulates RNA polymerase II output.\n\nTranscriptional control by an ETS core typically bifurcates into activation and repression depending on recruited cofactors. The presence of a compact Ets domain and absence of catalytic modules point to a regulatory role that tunes transcriptional initiation and elongation via co-regulator assembly. Such assemblies frequently include corepressors and histone-modifying enzymes, which mechanistically explains negative regulation of transcription by RNA polymerase II (GO:0000122). In developmental contexts, ETS factors often gate lineage programs; here, repression of target loci that steer early germ layer patterning and somatic sex determination provides a causal route to roles in embryogenesis and somatic sex determination.\n\nCellular localization follows directly from function and architecture. A winged-helix DNA-binding module dictates chromatin engagement within the nucleus. The soluble, non-membranous nature of the architecture and its role in transcriptional regulation place the protein in the nucleoplasm (GO:0005654), consistent with a nuclear residence where transcriptional machinery and chromatin are concentrated.\n\nMechanistically, I hypothesize that the protein binds purine-rich ETS motifs at regulatory elements and nucleates repressive complexes by recruiting corepressors and histone deacetylases. This repression likely sharpens developmental gene-expression boundaries during embryogenesis and somatic sex determination. Likely interaction partners include general RNA polymerase II regulatory assemblies and chromatin-modifying co-repressors; cooperative or competitive crosstalk with other ETS family members would refine motif occupancy and transcriptional outcomes.","category":"dark","control_evaluation":null,"validation_plan":null,"structure":{"source":"AlphaFold DB","pdb":"/structures/AF-Q6ZN32.pdb","alphafold":"https://alphafold.ebi.ac.uk/entry/Q6ZN32"},"links":{"uniprot":"https://www.uniprot.org/uniprotkb/Q6ZN32/entry","atlas":"/p/Q6ZN32"},"provenance":{"model":"BioReason-Pro (ESM3 esm3-sm-open-v1)","source_list":"Pharos Tdark","note":"AI prediction, not experimentally verified"}}