nucleolar exosome (RNase complex)

GO:0101019 · Ribonucleoprotein · Multiprotein complex · Proposed

A ribonuclease complex that has 3-prime to 5-prime distributive hydrolytic exoribonuclease activity and in some taxa (e.g. yeast) endoribonuclease activity, producing 5-prime-phosphomonoesters. Participates in a multitude of cellular RNA processing and degradation events preventing nuclear export and/or translation of aberrant RNAs. Restricted to processing linear and circular single-stranded RNAs (ssRNA) only. RNAs with complex secondary structures may have to be unwound or pre-processed by co-factors prior to entering the complex, esp if the 3-prime end is structured. [GO:0101019]

Part of: nucleolus (GO:0005730)

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

Functions

• RNA catabolic process GO:0006401 — The nucleolar exosome participates in degradation of RNA substrates.
  • GO:0006401 GO:0006401 is the Gene Ontology biological-process term for RNA catabolic process.
  • GO:0101019 GO:0101019 defines the nucleolar exosome RNase complex as participating in RNA degradation events.
• RNA processing GO:0006396 — The nucleolar exosome participates in processing RNA transcripts.
  • GO:0006396 GO:0006396 is the Gene Ontology biological-process term for RNA processing.
  • GO:0101019 GO:0101019 defines the nucleolar exosome RNase complex as participating in RNA processing events.

Mechanism graphs

Nucleolar exosome acts in RNA processing and decay (FUNCTION)

GO defines the nucleolar exosome as an exosome RNase complex located in the nucleolus that participates in RNA processing and degradation events.

Discussions

• CURATION_TODO (OPEN): Resolve exact source-neutral component boundaries for nucleolar exosome RNase complexes. The first GO:0101019 record captures the GO-defined nucleolar exosome localization and RNA processing/decay activities. Exact source-neutral boundaries for the nine-subunit core, catalytic nucleases and nucleolar cofactors should be curated from primary component evidence before assigning constituents.

Evidence

• GO:0101019 Gene Ontology cellular-component term for the nucleolar exosome RNase complex.
• GO:0000176 Gene Ontology cellular-component term for the broader nuclear exosome RNase complex.
• GO:0000178 Gene Ontology cellular-component term for the broader exosome RNase complex in the GO:0101019 logical definition.
• GO:0005730 Gene Ontology cellular-component term for the nucleolus in the GO:0101019 logical definition.
• GO:0006401 Gene Ontology biological-process term for RNA catabolic process.
• GO:0006396 Gene Ontology biological-process term for RNA processing.
• PMID:17174896 Liu, Greimann and Lima 2006, Reconstitution, activities, and structure of the eukaryotic RNA exosome, Cell; PMID cited in the GO:0101019 definition xrefs.
• PMID:20531386 Tomecki et al. 2010, The human core exosome interacts with differentially localized processive RNases: hDIS3 and hDIS3L, EMBO Journal; PMID cited in the GO:0101019 definition xrefs.
• PMID:26726035 Kilchert, Wittmann and Vasiljeva 2016, The regulation and functions of the nuclear RNA exosome complex, Nature Reviews Molecular Cell Biology; PMID cited in the GO:0101019 definition xrefs.

Curation history

• 2026-09-25T14:00:42Z codex · CREATED_RECORD — Scaffolded by scripts/new_record.py
• 2026-09-25T14:03:22Z codex · EXPANDED_RECORD — Added nucleolar exosome parentage and parthood, conservative GO-backed RNA processing and degradation functions, GO/PubMed evidence, a nonmechanistic localization/function graph and a component-boundary TODO.
• 2026-09-25T14:13:42Z codex · ADDRESS_REVIEW — #1581: changed the nucleolar exosome from RIBONUCLEOPROTEIN_COMPLEX to MULTIPROTEIN_COMPLEX to match its GO:0000178 exosome RNase complex parent.

Source: data/structures/ribonucleoprotein/nucleolar_exosome_rnase_complex.yaml