U4atac snRNP
A ribonucleoprotein complex that contains small nuclear RNA U4atac, a heptameric ring of Sm proteins, as well as several proteins that are unique to the U4atac snRNP, most of which remain associated with the U4atac snRNA both while the U4atac snRNP is free or assembled into the U4atac/U6atac complex or into a series of spliceosomal complexes. [GO:0005690]
Synonyms: snRNP U4atac
Components
| Component | Type | Part of / acts on | Grounding | Genes | Stoichiometry | Essential | Role |
|---|---|---|---|---|---|---|---|
| U4atac snRNA | Rna | part of | SO:0000394 | U4atac small nuclear RNA constituent named in the U4atac snRNP definition and grounded to the U4atac snRNA Sequence Ontology term.
| |||
| Sm protein ring | Protein complex | part of | Reviewed label only (reviewed name; no accession asserted) | Heptameric Sm protein-ring constituent named in the U4atac snRNP definition.
|
Taxonomic distribution
NCBITaxon:9606Homo sapiens — COMMON: The U4atac snRNP subcomplex is represented in human U4atac/U6atac.U5 tri-snRNPs analyzed biochemically by Schneider, Will, Makarova and colleagues; broader eukaryotic distribution is left for follow-up curation. [DOI:10.1128/MCB.22.10.3219-3229.2002]
Canonical examples
NCBITaxon:9606Homo sapiens — Human minor-spliceosome U4atac snRNP represented inside U4atac/U6atac.U5 tri-snRNPs in the Schneider, Will and Makarova comparative composition study. [DOI:10.1128/MCB.22.10.3219-3229.2002]
Mechanism graphs
U4atac snRNA and the Sm ring are U4atac snRNP constituents (ASSEMBLY)
The U4atac snRNP contains U4atac small nuclear RNA and a heptameric Sm protein ring; GO:0005690 also states that additional U4atac-specific proteins are present, with exact family boundaries still to be resolved.
| Subject | Predicate | Object | Evidence |
|---|---|---|---|
| U4atac snRNA | contributes constituents to | U4atac snRNP |
|
| Sm protein ring | contributes constituents to | U4atac snRNP |
|
Discussions
- CURATION_TODO (OPEN): Resolve exact source-neutral groundings for the Sm ring and U4atac-specific protein families that form the U4atac snRNP. The first GO:0005690 record captures U4atac snRNA and the GO-defined Sm ring at coarse granularity. Individual spliceosomal Sm proteins and U4atac-specific protein-family boundaries should be resolved before splitting this inventory.
Evidence
GO:0005690Gene Ontology cellular-component term for the U4atac snRNP and its exact synonym.GO:0097525Gene Ontology cellular-component parent term for spliceosomal snRNP complex.SO:0000394Sequence Ontology term for U4atac snRNA.DOI:10.1128/MCB.22.10.3219-3229.2002Schneider, Will, Makarova and colleagues 2002, Human U4/U6.U5 and U4atac/U6atac.U5 tri-snRNPs exhibit similar protein compositions, Molecular and Cellular Biology.PMID:11971955PubMed identifier for Schneider, Will, Makarova and colleagues 2002 as reported by NCBI E-utilities.DOI:10.1515/BC.2005.084Will and Luehrmann 2005, Splicing of a rare class of introns by the U12-dependent spliceosome, Biological Chemistry.PMID:16201866PubMed identifier for Will and Luehrmann 2005 as reported by NCBI E-utilities.
Curation history
2026-09-24T20:35:08Zcodex · CREATED_RECORD — Scaffolded by scripts/new_record.py2026-09-24T20:35:42Zcodex · EXPANDED_RECORD — Added the GO exact synonym, spliceosomal snRNP parentage, U4atac snRNA and Sm-ring components, human Schneider/Will/Makarova tri-snRNP evidence, a minimal U4atac snRNP constituent graph and a protein-component grounding TODO.2026-09-24T20:45:24Zcodex · ADDRESS_REVIEW — #1523: reworded the U4atac graph description so it no longer implies GO:0005690 enumerates individual U4atac-specific proteins.