U11/U12 snRNP

GO:0034693 · Ribonucleoprotein · Ribonucleoprotein complex · Proposed

A ribonucleoprotein complex that is formed by the association of the U11 and U12 small nuclear ribonucleoproteins. [GO:0034693]

Synonyms: snRNP U11/U12; 18S U11/U12 snRNP

Components

Component	Type	Part of / acts on	Grounding	Genes	Stoichiometry	Essential	Role
U11 snRNP	Protein complex	part of	`GO:0005692`				U11 small nuclear ribonucleoprotein subparticle that associates with the U12 snRNP to form the U11/U12 snRNP. `GO:0034693` GO:0034693 defines the U11/U12 snRNP as formed by the association of the U11 and U12 snRNPs. `GO:0005692` GO:0005692 is the Gene Ontology cellular-component term for the U11 snRNP.
U12 snRNP	Protein complex	part of	`GO:0005693`				U12 small nuclear ribonucleoprotein subparticle that associates with the U11 snRNP to form the U11/U12 snRNP. `GO:0034693` GO:0034693 defines the U11/U12 snRNP as formed by the association of the U11 and U12 snRNPs. `GO:0005693` GO:0005693 is the Gene Ontology cellular-component term for the U12 snRNP.

NCBITaxon:9606 Homo sapiens — COMMON: Human 18S U11/U12 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]

NCBITaxon:9606 Homo sapiens — Human minor-spliceosome 18S U11/U12 snRNPs affinity purified for compositional analysis by Will, Schneider and Hossbach. [DOI:10.1261/rna.7320604]

The U11/U12 snRNP forms from U11 and U12 small nuclear ribonucleoprotein subparticles.

Subject	Predicate	Object	Evidence
U11 snRNP	contributes constituents to	U11/U12 snRNP	`GO:0034693` GO:0034693 defines the U11/U12 snRNP as formed by the association of U11 and U12 snRNPs.
U12 snRNP	contributes constituents to	U11/U12 snRNP	`GO:0034693` GO:0034693 defines the U11/U12 snRNP as formed by the association of U11 and U12 snRNPs.

CURATION_TODO (OPEN): Resolve exact source-neutral component boundaries for the proteins present in human 18S U11/U12 snRNPs. The first GO:0034693 record captures the GO-grounded U11 and U12 snRNP subparticles. Will, Schneider, Hossbach and colleagues identified multiple 18S U11/U12 proteins by mass spectrometry; their source-neutral family boundaries should be resolved before splitting that protein inventory.

GO:0034693 Gene Ontology cellular-component term for the U11/U12 snRNP and its synonyms.
GO:0097525 Gene Ontology cellular-component parent term for spliceosomal snRNP complex.
GO:0005692 Gene Ontology cellular-component term for the U11 snRNP.
GO:0005693 Gene Ontology cellular-component term for the U12 snRNP.
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.

2026-09-24T22:41:14Z codex · CREATED_RECORD — Scaffolded by scripts/new_record.py
2026-09-24T22:42:05Z codex · EXPANDED_RECORD — Added GO exact and narrow synonyms, spliceosomal snRNP parentage, GO-grounded U11 and U12 snRNP components, human Will/Schneider/Hossbach 18S U11/U12 snRNP evidence, a minimal association graph and a protein-component grounding TODO.
2026-09-24T22:54:42Z codex · ADDRESS_REVIEW — #1531: clarified the U11/U12 snRNP protein-boundary TODO so it asks for proteins present in human 18S U11/U12 snRNPs rather than proteins forming affinity-purified particles.