UTP-C complex

GO:0034456 · Other · Multiprotein complex · Proposed

A protein complex that forms a subcomplex of the 90S preribosome. In S. cerevisiae, it is composed of Rrp7p, Utp22p, Ckb1p, Cka1p, Ckb2p and Cka2p. [GO:0034456]

Synonyms: Rrp7p-containing subcomplex of 90S preribosome

Part of: nucleolus (GO:0005730); 90S preribosome (GO:0030686)

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

Components

Component	Type	Part of / acts on	Grounding	Genes	Essential	Role
Rrp7 UTP-C subunit	Protein	part of	Reviewed label only (reviewed name; no accession asserted)	RRP7	UNKNOWN	Protein constituent of the budding-yeast UTP-C complex / Rrp7p-containing 90S-preribosome subcomplex. `GO:0034456` GO:0034456 defines the UTP-C complex as containing Rrp7p.
Utp22 UTP-C subunit	Protein	part of	Reviewed label only (reviewed name; no accession asserted)	UTP22	UNKNOWN	Protein constituent of the budding-yeast UTP-C complex / Rrp7p-containing 90S-preribosome subcomplex. `GO:0034456` GO:0034456 defines the UTP-C complex as containing Utp22p.
Ckb1 UTP-C subunit	Protein	part of	Reviewed label only (reviewed name; no accession asserted)	CKB1	UNKNOWN	Protein constituent of the budding-yeast UTP-C complex / Rrp7p-containing 90S-preribosome subcomplex. `GO:0034456` GO:0034456 defines the UTP-C complex as containing Ckb1p.
Cka1 UTP-C subunit	Protein	part of	Reviewed label only (reviewed name; no accession asserted)	CKA1	UNKNOWN	Protein constituent of the budding-yeast UTP-C complex / Rrp7p-containing 90S-preribosome subcomplex. `GO:0034456` GO:0034456 defines the UTP-C complex as containing Cka1p.
Ckb2 UTP-C subunit	Protein	part of	Reviewed label only (reviewed name; no accession asserted)	CKB2	UNKNOWN	Protein constituent of the budding-yeast UTP-C complex / Rrp7p-containing 90S-preribosome subcomplex. `GO:0034456` GO:0034456 defines the UTP-C complex as containing Ckb2p.
Cka2 UTP-C subunit	Protein	part of	Reviewed label only (reviewed name; no accession asserted)	CKA2	UNKNOWN	Protein constituent of the budding-yeast UTP-C complex / Rrp7p-containing 90S-preribosome subcomplex. `GO:0034456` GO:0034456 defines the UTP-C complex as containing Cka2p.

Taxonomic distribution

NCBITaxon:4932 Saccharomyces cerevisiae — COMMON: Budding yeast is the organism in which GO:0034456 defines UTP-C as a six-protein subcomplex of the 90S preribosome. [GO:0034456]

Canonical examples

NCBITaxon:4932 Saccharomyces cerevisiae — Perez-Fernandez et al. 2007 placed UTP-C on a stepwise 90S-preribosome assembly route in budding yeast. [DOI:10.1128/MCB.00380-07]

Functions

90S preribosome assembly GO:0034463 — The UTP-C complex forms a subcomplex of the 90S preribosome and participates in a stepwise assembly route for the yeast 90S preribosomal particle.
- GO:0034456 GO:0034456 defines UTP-C as a subcomplex of the 90S preribosome.
- GO:0034463 GO:0034463 is the Gene Ontology biological-process term for 90S preribosome assembly.
- DOI:10.1128/MCB.00380-07 Perez-Fernandez et al. 2007 placed stepwise binding of Rrp5p and UTP-C on one 90S-preribosome assembly route.

Mechanism graphs

UTP-C is a 90S preribosome assembly module (ASSEMBLY)

In Saccharomyces cerevisiae, the six-protein UTP-C complex forms a subcomplex of the 90S preribosome and joins the hierarchical assembly pathway.

Subject	Predicate	Object	Evidence
Rrp7 UTP-C subunit	contributes to	UTP-C complex	`GO:0034456` GO:0034456 defines Rrp7p as a component of the UTP-C complex.
Utp22 UTP-C subunit	contributes to	UTP-C complex	`GO:0034456` GO:0034456 defines Utp22p as a component of the UTP-C complex.
Ckb1 UTP-C subunit	contributes to	UTP-C complex	`GO:0034456` GO:0034456 defines Ckb1p as a component of the UTP-C complex.
Cka1 UTP-C subunit	contributes to	UTP-C complex	`GO:0034456` GO:0034456 defines Cka1p as a component of the UTP-C complex.
Ckb2 UTP-C subunit	contributes to	UTP-C complex	`GO:0034456` GO:0034456 defines Ckb2p as a component of the UTP-C complex.
Cka2 UTP-C subunit	contributes to	UTP-C complex	`GO:0034456` GO:0034456 defines Cka2p as a component of the UTP-C complex.
UTP-C complex	part of	90S preribosome	`GO:0034456` GO:0034456 records UTP-C as part of the 90S preribosome.
UTP-C complex	supports	90S preribosome assembly	`GO:0034456` GO:0034456 defines UTP-C as a subcomplex of the 90S preribosome. `GO:0034463` GO:0034463 is the process term for 90S preribosome assembly. `DOI:10.1128/MCB.00380-07` Perez-Fernandez et al. 2007 described UTP-C as a discrete assembly subunit that binds during one of the 90S preribosome assembly routes.

Discussions

CURATION_TODO (OPEN): Resolve exact source-neutral family groundings for the Rrp7, Utp22, Ckb1, Cka1, Ckb2 and Cka2 constituents of the UTP-C complex. GO:0034456 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 the six UTP-C proteins need narrower follow-up curation before these component labels can be grounded.

Evidence

GO:0034456 Gene Ontology cellular-component term for the UTP-C complex and its exact Rrp7p-containing-subcomplex synonym.
GO:0140513 Gene Ontology cellular-component parent term for nuclear protein-containing complexes.
GO:0005730 Gene Ontology cellular-component term for the nucleolus.
GO:0030686 Gene Ontology cellular-component term for the 90S preribosome.
GO:0034463 Gene Ontology biological-process term for 90S preribosome assembly.
PMID:17515605 PubMed identifier for Perez-Fernandez et al. 2007, the Molecular and Cellular Biology paper cited by GO:0034456.
DOI:10.1128/MCB.00380-07 DOI for Perez-Fernandez et al. 2007, 'The 90S preribosome is a multimodular structure that is assembled through a hierarchical mechanism', verified through NCBI E-utilities.

Curation history

2026-09-25T22:21:06Z codex · CREATED_RECORD — Scaffolded by scripts/new_record.py
2026-09-25T22:21:55Z codex · EXPANDED_RECORD — Added Rrp7p-containing-subcomplex synonymy, nuclear protein-containing complex parentage, nucleolar and 90S preribosome parthood, six reviewed-label-only UTP-C constituent rows, budding-yeast scope, a 90S-preribosome-assembly function, GO/PubMed/DOI evidence, a nonmechanistic assembly graph, and a UTP-C subunit-grounding TODO.

Source: data/structures/other/utp_c_complex.yaml