{"uniprot":"Q6IPX3","gene":"TCEAL6","name":"Transcription elongation factor A protein-like 6","organism":"Homo sapiens (Human)","status":"dark","length":200,"sequence":"MEKPYNKNEGNLENEGKPEDEVEPDDEGKSDEEEKPDAEGKTECEGKRKAEGEPGDEGQLEDKGSQEKQGKSEGEGKPQGEGKPASQAKPEGQPRAAEKRPAGDYVPRKAKRKTDRGTDDSPKDSQEDLQERHLSSEEMMRECGDVSRAQEELRKKQKMGGFHWMQRDVQDPFAPRGQRGVRGVRGGGRGQRGLHDIPYL","function_summary":"A soluble regulatory scaffold that uses a TCEA-like core to assemble transcription and RNA-processing complexes, thereby tuning RNA polymerase II elongation and pre-mRNA maturation in human cells. By coordinating elongation and splicing modules in the nucleus and dynamically shuttling through the cytosol, it dampens pro-proliferative transcriptional programs and contributes to orderly cell-cycle control, with occasional membrane-proximal signaling inputs shaping its nuclear activity.","plain_language":"TCEAL6 has barely been studied. The model's best guess: A soluble regulatory scaffold that uses a TCEA-like core to assemble transcription and RNA-processing complexes, thereby tuning RNA polymerase II elongation and pre-mRNA maturation in human cells. By coordinating elongation and splicing modules in the nucleus and dynamically shuttling through the cytosol, it dampens pro-proliferative transcriptional programs and contributes to orderly cell-cycle control, with occasional membrane-proximal signaling inputs shaping its nuclear activity.","uniprot_summary":"Could be involved in the regulation of cell proliferation.","go_terms":{"molecular_function":[{"id":"GO:0005515","label":"protein binding"}],"biological_process":[{"id":"GO:0008285","label":"negative regulation of cell population proliferation"}],"cellular_component":[{"id":"GO:0005654","label":"nucleoplasm"},{"id":"GO:0005829","label":"cytosol"},{"id":"GO:0005886","label":"plasma membrane"}]},"interpro":[{"id":"IPR021156","name":"Transcription elongation factor A-like/Brain expressed X-linked","type":"family","start":72,"end":176}],"reasoning":"I begin with the InterPro architecture: a single central family signature IPR021156 (Transcription elongation factor A-like/Brain expressed X-linked family) spanning residues 72–176. This compact, non-enzymatic module typifies the TCEA-like/BEX superfamily—soluble nuclear factors that lack catalytic motifs but form regulatory scaffolds. Their conserved core is flanked by low-complexity regions that mediate multivalent contacts with transcription machinery and RNA-processing assemblies. The absence of enzymatic domains and the presence of a TCEA-like core causally point to a binding-centric mechanism, supporting a primary molecular function of protein binding (GO:0005515).\n\nA TCEA-like scaffold typically tunes RNA polymerase II elongation and co-transcriptional RNA maturation by docking elongation factors and chromatin-associated complexes. Such assemblies often gate expression of growth-control genes and can attenuate pro-proliferative transcriptional programs. This regulatory logic—modulating elongation and transcript processing to restrain cell-cycle drivers—aligns with negative regulation of cell population proliferation (GO:0008285). The same architecture that stabilizes elongation complexes can also recruit repressive modules, thereby coupling transcriptional output to cell-cycle restraint.\n\nCellular localization follows from function and architecture. TCEA-like factors operate where transcription and pre-mRNA processing occur—the nucleoplasm (GO:0005654)—consistent with a soluble nuclear pool. Dynamic shuttling and cytoplasmic sequestration are common for regulatory scaffolds, explaining a cytosolic fraction (GO:0005829). Occasional association with membrane-proximal signaling hubs that feed back into transcription rationalizes transient detection at the plasma membrane (GO:0005886), where receptor pathways modulate nuclear gene expression.\n\nMechanistically, I hypothesize that the TCEA-like core nucleates assemblies with RNA polymerase II elongation machinery and RNA-processing factors to fine-tune gene output. By stabilizing elongation complexes and coordinating co-transcriptional splicing, the protein dampens expression of proliferation drivers and supports orderly cell-cycle progression. Likely partners include TCEA/FACT-related modules and nucleoplasmic ribonucleoproteins; membrane-proximal cues from receptor signaling may further tune its nuclear activity via shuttling between cytosol and nucleoplasm.","category":"dark","control_evaluation":null,"validation_plan":null,"structure":{"source":"AlphaFold DB","pdb":"/structures/AF-Q6IPX3.pdb","alphafold":"https://alphafold.ebi.ac.uk/entry/Q6IPX3"},"links":{"uniprot":"https://www.uniprot.org/uniprotkb/Q6IPX3/entry","atlas":"/p/Q6IPX3"},"provenance":{"model":"BioReason-Pro (ESM3 esm3-sm-open-v1)","source_list":"Pharos Tdark","note":"AI prediction, not experimentally verified"}}