Noc1p-Noc2p complex

GO:0030690 · Other · Multiprotein complex · Proposed

A heterodimer associated with 90S and 66S preribosomes. Predominantly, but not exclusively, nucleolar; involved in ribosomal large subunit biogenesis. [GO:0030690]

Part of: 90S preribosome (GO:0030686); preribosome, large subunit precursor (GO:0030687)

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
Noc1 Noc-complex subunit	Protein	part of	Reviewed label only (reviewed name; no accession asserted)	NOC1	one copy per heterodimer	UNKNOWN	Protein constituent that forms the budding-yeast Noc1p-Noc2p heterodimer associated with 90S and 66S preribosomes. `GO:0030690` GO:0030690 defines the Noc1p-Noc2p complex as a heterodimer associated with 90S and 66S preribosomes. `DOI:10.1016/s0092-8674(01)00358-0` Milkereit et al. 2001 isolated Noc1p and Noc2p in one of two distinct Noc complexes involved in pre-ribosome maturation and intranuclear transport.
Noc2 Noc-complex subunit	Protein	part of	Reviewed label only (reviewed name; no accession asserted)	NOC2	one copy per heterodimer	UNKNOWN	Protein constituent shared by the budding-yeast Noc1p-Noc2p and Noc2p-Noc3p complexes. `GO:0030690` GO:0030690 identifies Noc2p in the Noc1p-Noc2p heterodimer associated with 90S and 66S preribosomes. `DOI:10.1016/s0092-8674(01)00358-0` Milkereit et al. 2001 reported that Noc2p participates in two distinct Noc complexes, Noc1p/Noc2p and Noc2p/Noc3p.

Taxonomic distribution

NCBITaxon:4932 Saccharomyces cerevisiae — COMMON: Budding yeast is the organism in which Noc1p-Noc2p was described as a heterodimeric Noc complex associated with 90S and 66S preribosomes. [DOI:10.1016/s0092-8674(01)00358-0]

Canonical examples

NCBITaxon:4932 Saccharomyces cerevisiae — Milkereit et al. 2001 isolated budding-yeast Noc1p/Noc2p as a preribosome-associated Noc complex enriched in the nucleolus. [DOI:10.1016/s0092-8674(01)00358-0]

Functions

ribosomal large subunit biogenesis GO:0042273 — The Noc1p-Noc2p complex is associated with 90S and 66S preribosomes and supports maturation of the eukaryotic large ribosomal subunit lineage.
- GO:0030690 GO:0030690 defines the Noc1p-Noc2p complex as involved in ribosomal large subunit biogenesis.
- GO:0042273 GO:0042273 is the Gene Ontology biological-process term for ribosomal large subunit biogenesis.
- DOI:10.1016/s0092-8674(01)00358-0 Milkereit et al. 2001 connected Noc1p/Noc2p to 90S and 66S pre-ribosomes and to intranuclear 60S subunit maturation and transport.

Mechanism graphs

Noc1p-Noc2p associates with large-subunit preribosomes (FUNCTION)

In Saccharomyces cerevisiae, Noc1p and Noc2p form a heterodimeric Noc complex that associates with 90S and 66S pre-ribosomes during large ribosomal subunit maturation.

Subject	Predicate	Object	Evidence
Noc1 Noc-complex subunit	contributes to	Noc1p-Noc2p complex	`DOI:10.1016/s0092-8674(01)00358-0` Milkereit et al. 2001 isolated Noc1p/Noc2p as a distinct Noc complex.
Noc2 Noc-complex subunit	contributes to	Noc1p-Noc2p complex	`DOI:10.1016/s0092-8674(01)00358-0` Milkereit et al. 2001 isolated Noc1p/Noc2p as a distinct Noc complex.
Noc1p-Noc2p complex	associates with	90S preribosome	`GO:0030690` GO:0030690 defines the Noc1p-Noc2p complex as associated with 90S and 66S preribosomes. `DOI:10.1016/s0092-8674(01)00358-0` Milkereit et al. 2001 reported Noc1p/Noc2p association with 90S pre-ribosomes.
Noc1p-Noc2p complex	associates with	preribosome, large subunit precursor	`GO:0030690` GO:0030690 defines the Noc1p-Noc2p complex as associated with 90S and 66S preribosomes and as part of the large-subunit precursor. `DOI:10.1016/s0092-8674(01)00358-0` Milkereit et al. 2001 reported Noc1p/Noc2p association with 66S pre-ribosomes.
Noc1p-Noc2p complex	participates in	ribosomal large subunit biogenesis	`GO:0030690` GO:0030690 defines this complex as involved in ribosomal large subunit biogenesis. `GO:0042273` GO:0042273 is the process term for ribosomal large subunit biogenesis.

Discussions

CURATION_TODO (OPEN): Resolve exact source-neutral family groundings for the Noc1 and Noc2 constituents of the Noc1p-Noc2p complex. GO:0030690 uses Saccharomyces gene-product names while noting that analogous complexes in other eukaryotes can use the term. Exact cross-eukaryotic InterPro, Pfam, NCBIfam or UniProt family boundaries for Noc1 and Noc2 need narrower follow-up curation before these component labels can be grounded.

Evidence

GO:0030690 Gene Ontology cellular-component term for the Noc1p-Noc2p complex.
GO:0030689 Gene Ontology cellular-component parent term for Noc complexes.
GO:0030686 Gene Ontology cellular-component term for the 90S preribosome.
GO:0030687 Gene Ontology cellular-component term for the large-subunit preribosome precursor.
GO:0042273 Gene Ontology biological-process term for ribosomal large subunit biogenesis.
PMID:11371346 PubMed identifier for Milkereit et al. 2001, 'Maturation and intranuclear transport of pre-ribosomes requires Noc proteins'.
DOI:10.1016/s0092-8674(01)00358-0 DOI for Milkereit et al. 2001, Cell, verified through NCBI E-utilities.
PMID:12446671 PubMed identifier for Milkereit et al. 2003, the Journal of Biological Chemistry paper cited by the GO Noc-complex terms.
DOI:10.1074/jbc.M208898200 DOI for Milkereit et al. 2003, the Noc4p-Nop14p study that framed Noc4p-Nop14p together with the Noc1p-Noc2p and Noc2p-Noc3p heterodimers.

Curation history

2026-09-25T20:26:44Z codex · CREATED_RECORD — Scaffolded by scripts/new_record.py
2026-09-25T20:28:05Z codex · EXPANDED_RECORD — Added Noc-complex parentage, 90S and large-subunit preribosome parthood, Noc1 and Noc2 constituent rows, budding-yeast scope, a large-subunit biogenesis function, GO/PubMed/DOI evidence, a nonmechanistic Noc1p-Noc2p graph, and a subunit-grounding TODO.

Source: data/structures/other/noc1p_noc2p_complex.yaml