post-spliceosomal complex

GO:0071020 · Ribonucleoprotein · Ribonucleoprotein complex · Proposed

A spliceosomal complex that is formed following the second splicing event and contains the spliced product, the excised intron, and three snRNPs, including U5. [GO:0071020]

Synonyms: mammalian spliceosomal complex C2; yeast spliceosomal complex A2-3

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
U5 snRNP	Protein complex	part of	`GO:0005682`				Conserved small nuclear ribonucleoprotein bound with the spliced product and excised intron in post-spliceosomal complexes. `GO:0071020` GO:0071020 defines the post-spliceosomal complex as containing three snRNPs including U5. `GO:0005682` GO:0005682 is the Gene Ontology cellular-component term for the U5 snRNP. `GO:0071021` GO:0071021 names U5 as one of the U2-type post-spliceosomal complex snRNPs. `GO:0071022` GO:0071022 names U5 as one of the U12-type post-spliceosomal complex snRNPs.
post-spliceosomal subtype-specific partner snRNPs	Protein complex	part of	Reviewed label only (reviewed name; no accession asserted)				Subtype-specific pair of non-U5 snRNP constituents bound with the spliced product and excised intron in post-spliceosomal complexes. `GO:0071020` GO:0071020 defines the post-spliceosomal complex as containing three snRNPs including U5, leaving two additional subtype-specific snRNP constituents. `GO:0071021` GO:0071021 defines the U2-type post-spliceosomal complex as containing U2 and U6 snRNPs alongside U5. `GO:0071022` GO:0071022 defines the U12-type post-spliceosomal complex as containing U12 and U6atac snRNPs alongside U5.

Mechanism graphs

U5 and subtype-specific snRNPs bind post-splicing products (ASSEMBLY)

Post-spliceosomal complexes contain a conserved U5 snRNP, two subtype-specific partner snRNPs, the spliced product and the excised intron after the second splicing event.

Subject	Predicate	Object	Evidence
U5 snRNP	remains associated with splicing products in	post-spliceosomal complex	`GO:0071020` GO:0071020 defines post-spliceosomal complexes as including U5 after the second splicing event.
post-spliceosomal subtype-specific partner snRNPs	remain associated with splicing products in	post-spliceosomal complex	`GO:0071021` GO:0071021 defines the U2-type post-spliceosomal complex as containing U2, U5 and U6 snRNPs. `GO:0071022` GO:0071022 defines the U12-type post-spliceosomal complex as containing U12, U5 and U6atac snRNPs.
catalytic step 2 spliceosome	is remodeled following the second splicing event to form	post-spliceosomal complex	`GO:0071020` GO:0071020 defines the post-spliceosomal complex as formed following the second splicing event.

Discussions

CURATION_TODO (OPEN): Resolve exact source-neutral non-U5 snRNP membership, spliced-product RNA, excised-intron RNA and additional protein boundaries for each post-spliceosomal complex subtype. The GO:0071020 parent record captures the generic presence of a conserved U5 snRNP, two non-U5 snRNPs whose exact identities depend on the U2-type or U12-type spliceosome subtype and RNA products of the second splicing event. Child records for U2-type and U12-type post-spliceosomal complexes carry the exact U2/U6 and U12/U6atac partner-snRNP boundaries that apply to those specific states, while exact protein-family and RNA substrate boundaries remain to be curated.

Evidence

GO:0071020 Gene Ontology cellular-component term for post-spliceosomal complex and its GO narrow synonyms.
GO:0005681 Gene Ontology cellular-component parent term for spliceosomal complex.
GO:0071013 Gene Ontology cellular-component term for the preceding catalytic step 2 spliceosome state.
GO:0071021 Gene Ontology cellular-component term for the U2-type post-spliceosomal complex child state.
GO:0071022 Gene Ontology cellular-component term for the U12-type post-spliceosomal complex child state.
GO:0005682 Gene Ontology cellular-component term for the U5 snRNP.
GO:0005686 Gene Ontology cellular-component term for the U2 snRNP.
GO:0005688 Gene Ontology cellular-component term for the U6 snRNP.
GO:0005693 Gene Ontology cellular-component term for the U12 snRNP.
GO:0005691 Gene Ontology cellular-component term for the U6atac snRNP.

Curation history

2026-09-25T09:51:07Z codex · CREATED_RECORD — Scaffolded by scripts/new_record.py
2026-09-25T09:51:52Z codex · EXPANDED_RECORD — Added GO narrow synonyms, spliceosomal-complex parentage, a GO-grounded U5 component, a reviewed-label-only pair of subtype-specific non-U5 snRNP components, a conservative post-second-splicing graph and a TODO for exact subtype-specific post-spliceosomal snRNP, protein and RNA boundaries.

Source: data/structures/ribonucleoprotein/post_spliceosomal_complex.yaml