U11 snRNP

GO:0005692 · Ribonucleoprotein · Ribonucleoprotein complex · Proposed

A ribonucleoprotein complex that contains small nuclear RNA U11, a heptameric ring of Sm proteins, as well as several proteins that are unique to the U11 snRNP, most of which remain associated with the U11 snRNA both while the U11 snRNP is free or assembled into a series of spliceosomal complexes. [GO:0005692]

Synonyms: snRNP U11; 12S U11 snRNP

UniProt location names: UniProt Consortium, CC BY 4.0. Reference label and route sources.

Components

Component	Type	Part of / acts on	Grounding	Genes	Stoichiometry	Essential	Role
U11 snRNA	Rna	part of	`SO:0000398`				U11 small nuclear RNA constituent named in the U11 snRNP definition and grounded to the U11 snRNA Sequence Ontology term. `GO:0005692` GO:0005692 defines the U11 snRNP as containing small nuclear RNA U11. `SO:0000398` SO:0000398 is the Sequence Ontology term for U11 snRNA.
Sm protein ring	Protein complex	part of	Reviewed label only (reviewed name; no accession asserted)				Heptameric Sm protein-ring constituent named in the U11 snRNP definition. `GO:0005692` GO:0005692 defines the U11 snRNP as containing a heptameric ring of Sm proteins.

Taxonomic distribution

NCBITaxon:9606 Homo sapiens — COMMON: Human 12S U11 snRNPs were affinity purified and analyzed by mass spectrometry by Will, Schneider, Hossbach and colleagues; broader eukaryotic distribution is left for follow-up curation. [DOI:10.1261/rna.7320604]

Canonical examples

NCBITaxon:9606 Homo sapiens — Human minor-spliceosome U11 snRNP represented by affinity-purified 12S U11 particles in the Will, Schneider and Hossbach composition study. [DOI:10.1261/rna.7320604]

Mechanism graphs

U11 snRNA and the Sm ring are U11 snRNP constituents (ASSEMBLY)

The U11 snRNP contains U11 small nuclear RNA and a heptameric Sm protein ring; GO:0005692 also states that additional U11-specific proteins are present, with exact family boundaries still to be resolved.

Subject	Predicate	Object	Evidence
U11 snRNA	contributes constituents to	U11 snRNP	`GO:0005692` GO:0005692 defines the U11 snRNP as containing small nuclear RNA U11.
Sm protein ring	contributes constituents to	U11 snRNP	`GO:0005692` GO:0005692 defines the U11 snRNP as containing a heptameric ring of Sm proteins.

Discussions

CURATION_TODO (OPEN): Resolve exact source-neutral groundings for the Sm ring and U11-specific protein families that form the U11 snRNP. The first GO:0005692 record captures U11 snRNA and the GO-defined Sm ring at coarse granularity. Individual spliceosomal Sm proteins and U11-specific protein-family boundaries should be resolved before splitting this inventory.

Evidence

GO:0005692 Gene Ontology cellular-component term for the U11 snRNP and its synonyms.
GO:0097525 Gene Ontology cellular-component parent term for spliceosomal snRNP complex.
SO:0000398 Sequence Ontology term for U11 snRNA.
DOI:10.1261/rna.7320604 Will, Schneider, Hossbach and colleagues 2004 affinity purified human 18S U11/U12 and 12S U11 snRNPs and identified their protein components by mass spectrometry.
DOI:10.1515/BC.2005.084 Will and Luehrmann 2005, Splicing of a rare class of introns by the U12-dependent spliceosome, Biological Chemistry.

Curation history

2026-09-24T21:37:46Z codex · CREATED_RECORD — Scaffolded by scripts/new_record.py
2026-09-24T21:38:32Z codex · EXPANDED_RECORD — Added the GO exact and narrow synonyms, spliceosomal snRNP parentage, U11 snRNA and Sm-ring components, human Will/Schneider/Hossbach 12S U11 snRNP evidence, a minimal U11 snRNP constituent graph and a protein-component grounding TODO.
2026-09-24T21:49:36Z codex · ADDRESS_REVIEW — #1527: clarified the Will/Schneider/Hossbach 2004 evidence note so it states the paper affinity purified 12S U11 snRNPs as well as 18S U11/U12 snRNPs.

Source: data/structures/ribonucleoprotein/u11_snrnp.yaml