post-mRNA release spliceosomal complex

GO:0071014 · Ribonucleoprotein · Ribonucleoprotein complex · Proposed

A spliceosomal complex that is formed following the release of the spliced product from the post-spliceosomal complex and contains the excised intron and three snRNPs, either U2 or U12, U5, and either U6 or U6atac. [GO:0071014]

Synonyms: mammalian spliceosomal complex I

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 retained with the excised intron in post-mRNA release spliceosomal complexes. `GO:0071014` GO:0071014 defines the post-mRNA release spliceosomal complex as containing three snRNPs including U5. `GO:0005682` GO:0005682 is the Gene Ontology cellular-component term for the U5 snRNP. `GO:0071008` GO:0071008 names U5 as one of the U2-type post-mRNA release spliceosomal complex snRNPs. `GO:0071019` GO:0071019 names U5 as one of the U12-type post-mRNA release spliceosomal complex snRNPs.
post-mRNA-release subtype-specific partner snRNPs	Protein complex	part of	Reviewed label only (reviewed name; no accession asserted)				Subtype-specific pair of non-U5 snRNP constituents retained with the excised intron in post-mRNA release spliceosomal complexes. `GO:0071014` GO:0071014 defines the post-mRNA release spliceosomal complex as containing three snRNPs including U5, leaving two additional subtype-specific snRNP constituents. `GO:0071008` GO:0071008 defines the U2-type post-mRNA release spliceosomal complex as containing U2 and U6 snRNPs alongside U5. `GO:0071019` GO:0071019 defines the U12-type post-mRNA release spliceosomal complex as containing U12 and U6atac snRNPs alongside U5.

Mechanism graphs

U5 and subtype-specific snRNPs remain with the excised intron (ASSEMBLY)

Post-mRNA release spliceosomal complexes retain a conserved U5 snRNP, two subtype-specific partner snRNPs and the excised intron after the spliced product is released from the post-spliceosomal complex.

Subject	Predicate	Object	Evidence
U5 snRNP	remains associated with the excised intron in	post-mRNA release spliceosomal complex	`GO:0071014` GO:0071014 defines post-mRNA release spliceosomal complexes as including U5 after spliced-product release.
post-mRNA-release subtype-specific partner snRNPs	remain associated with the excised intron in	post-mRNA release spliceosomal complex	`GO:0071008` GO:0071008 defines the U2-type post-mRNA release spliceosomal complex as containing U2, U5 and U6 snRNPs. `GO:0071019` GO:0071019 defines the U12-type post-mRNA release spliceosomal complex as containing U12, U5 and U6atac snRNPs.
post-spliceosomal complex	is remodeled after spliced-product release to form	post-mRNA release spliceosomal complex	`GO:0071014` GO:0071014 defines the post-mRNA release spliceosomal complex as formed following release of the spliced product from the post-spliceosomal complex.

Discussions

CURATION_TODO (OPEN): Resolve exact source-neutral non-U5 snRNP membership, excised-intron RNA and additional protein boundaries for each post-mRNA release spliceosomal complex subtype. The GO:0071014 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 the excised intron that remains after spliced-product release. Child records for U2-type and U12-type post-mRNA release spliceosomal complexes carry the exact U2/U6 and U12/U6atac partner-snRNP boundaries that apply to those specific states, while exact protein-family and excised-intron RNA boundaries remain to be curated.

Evidence

GO:0071014 Gene Ontology cellular-component term for post-mRNA release spliceosomal complex and its GO narrow synonym.
GO:0005681 Gene Ontology cellular-component parent term for spliceosomal complex.
GO:0071020 Gene Ontology cellular-component term for the preceding post-spliceosomal complex state.
GO:0071008 Gene Ontology cellular-component term for the U2-type post-mRNA release spliceosomal complex child state.
GO:0071019 Gene Ontology cellular-component term for the U12-type post-mRNA release 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

2026-09-25T10:16:02Z codex · CREATED_RECORD — Scaffolded by scripts/new_record.py
2026-09-25T10:16:55Z codex · EXPANDED_RECORD — Added the GO narrow synonym, spliceosomal-complex parentage, a GO-grounded U5 component, a reviewed-label-only pair of subtype-specific non-U5 snRNP components, a conservative post-mRNA-release graph and a TODO for exact subtype-specific post-mRNA-release snRNP, protein and RNA boundaries.
2026-09-25T10:27:59Z codex · ADDRESS_REVIEW — #1568: narrowed the generic post-mRNA-release transition edge to avoid modeling the post-spliceosomal complex itself as the spliced-product release agent.

Source: data/structures/ribonucleoprotein/post_mrna_release_spliceosomal_complex.yaml