THO complex

GO:0000347 · Other · Multiprotein complex · Proposed

A eukaryotic nuclear protein complex that promotes transcription elongation and can act as part of the transcription export complex to couple RNA polymerase II transcription with mRNA export from the nucleus. [GO:0000347]

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
Hpr1 subunit	Protein	part of	Reviewed label only (reviewed name; no accession asserted)	HPR1	UNKNOWN	Named Saccharomyces cerevisiae constituent of the four-subunit THO complex. `PMID:11060033` Chavez et al. 2000 identified a Saccharomyces cerevisiae protein complex containing Tho2p, Hpr1p, Mft1p and Thp2p. `DOI:10.1093/emboj/19.21.5824` DOI for the Chavez et al. 2000 EMBO Journal THO-complex paper, verified through PubMed.
Tho2 subunit	Protein	part of	Reviewed label only (reviewed name; no accession asserted)	THO2	UNKNOWN	Named Saccharomyces cerevisiae constituent of the four-subunit THO complex. `PMID:11060033` Chavez et al. 2000 identified a Saccharomyces cerevisiae protein complex containing Tho2p, Hpr1p, Mft1p and Thp2p. `DOI:10.1093/emboj/19.21.5824` DOI for the Chavez et al. 2000 EMBO Journal THO-complex paper, verified through PubMed.
Mft1 subunit	Protein	part of	Reviewed label only (reviewed name; no accession asserted)	MFT1	UNKNOWN	Named Saccharomyces cerevisiae constituent of the four-subunit THO complex. `PMID:11060033` Chavez et al. 2000 identified a Saccharomyces cerevisiae protein complex containing Tho2p, Hpr1p, Mft1p and Thp2p. `DOI:10.1093/emboj/19.21.5824` DOI for the Chavez et al. 2000 EMBO Journal THO-complex paper, verified through PubMed.
Thp2 subunit	Protein	part of	Reviewed label only (reviewed name; no accession asserted)	THP2	UNKNOWN	Named Saccharomyces cerevisiae constituent of the four-subunit THO complex. `PMID:11060033` Chavez et al. 2000 identified a Saccharomyces cerevisiae protein complex containing Tho2p, Hpr1p, Mft1p and Thp2p. `DOI:10.1093/emboj/19.21.5824` DOI for the Chavez et al. 2000 EMBO Journal THO-complex paper, verified through PubMed.

Taxonomic distribution

NCBITaxon:4932 Saccharomyces cerevisiae — COMMON: Budding yeast has a four-subunit THO complex containing Hpr1p, Tho2p, Mft1p and Thp2p. [PMID:11060033]

Canonical examples

NCBITaxon:4932 Saccharomyces cerevisiae — Reference budding-yeast system in which the Hpr1p, Tho2p, Mft1p and Thp2p THO complex was identified. [PMID:11060033]

Functions

DNA-templated transcription elongation GO:0006354 — The THO complex promotes transcription elongation, including transcription of repeat-containing genes.
- GO:0000347 GO:0000347 defines the THO complex as required for transcription elongation through genes containing tandem DNA repeats.
- GO:0006354 GO:0006354 is the Gene Ontology biological-process term for DNA-templated transcription elongation.
- PMID:16983072 Voynov et al. 2006 reported that genes with internal repeats require the THO complex for transcription.
mRNA export from nucleus GO:0006406 — The THO complex acts within the transcription export complex that couples transcription to mRNA export.
- GO:0000347 GO:0000347 describes THO as part of the TREX complex that couples transcription to mRNA export to the cytoplasm.
- GO:0006406 GO:0006406 is the Gene Ontology biological-process term for mRNA export from nucleus.
- PMID:11979277 Strasser et al. 2002 identified TREX as a conserved complex that couples transcription with mRNA export.

Mechanism graphs

THO supports transcription and mRNA export (FUNCTION)

Hpr1p, Tho2p, Mft1p and Thp2p form the Saccharomyces cerevisiae THO complex that supports transcription elongation and TREX-mediated coupling to mRNA export.

Subject	Predicate	Object	Evidence
Hpr1 subunit	contributes to	THO complex	`PMID:11060033` Chavez et al. 2000 identified a Saccharomyces cerevisiae THO complex containing Tho2p, Hpr1p, Mft1p and Thp2p.
Tho2 subunit	contributes to	THO complex	`PMID:11060033` Chavez et al. 2000 identified a Saccharomyces cerevisiae THO complex containing Tho2p, Hpr1p, Mft1p and Thp2p.
Mft1 subunit	contributes to	THO complex	`PMID:11060033` Chavez et al. 2000 identified a Saccharomyces cerevisiae THO complex containing Tho2p, Hpr1p, Mft1p and Thp2p.
Thp2 subunit	contributes to	THO complex	`PMID:11060033` Chavez et al. 2000 identified a Saccharomyces cerevisiae THO complex containing Tho2p, Hpr1p, Mft1p and Thp2p.
THO complex	supports	DNA-templated transcription elongation	`GO:0000347` GO:0000347 defines the THO complex as required for transcription elongation through genes containing tandemly repeated DNA sequences. `GO:0006354` GO:0006354 is the biological-process term for DNA-templated transcription elongation.
THO complex	supports	mRNA export from nucleus	`GO:0000347` GO:0000347 defines THO as part of the TREX complex involved in coupling transcription to mRNA export. `GO:0006406` GO:0006406 is the biological-process term for mRNA export from nucleus.

Discussions

CURATION_TODO (OPEN): Resolve exact source-neutral family groundings for the Hpr1, Tho2, Mft1 and Thp2 constituents of the THO complex. PMID:11060033 identifies the four named budding-yeast constituents of the THO complex, but exact source-neutral InterPro, Pfam, NCBIfam or UniProtKB family CURIEs for these subunit classes were not curated in this pass.

Evidence

GO:0000347 Gene Ontology cellular-component term for the THO complex.
GO:0140513 Gene Ontology cellular-component parent term for nuclear protein-containing complexes.
GO:0000346 Gene Ontology cellular-component term for the transcription export complex, which contains THO.
GO:0006354 Gene Ontology biological-process term for DNA-templated transcription elongation.
GO:0006406 Gene Ontology biological-process term for mRNA export from nucleus.
PMID:11060033 PubMed identifier for Chavez et al. 2000, the EMBO Journal paper identifying the four-protein Saccharomyces cerevisiae THO complex.
DOI:10.1093/emboj/19.21.5824 DOI for Chavez et al. 2000, verified through PubMed and PMC.
PMID:11979277 PubMed identifier for Strasser et al. 2002, the Nature paper identifying TREX as a conserved transcription-mRNA-export coupling complex.
DOI:10.1038/nature746 DOI for Strasser et al. 2002, verified through PubMed.
PMID:16983072 PubMed identifier for Voynov et al. 2006, the PNAS paper on THO-dependent transcription of genes with internal repeats.
DOI:10.1073/pnas.0606546103 DOI for Voynov et al. 2006, verified through PubMed and PMC.

Curation history

2026-09-27T14:22:23Z codex · CREATED_RECORD — Scaffolded by scripts/new_record.py
2026-09-27T14:23:14Z codex · EXPANDED_RECORD — Added nuclear protein-containing-complex parentage, transcription export complex parthood, four reviewed-label-only budding-yeast constituent rows, Saccharomyces cerevisiae scope, transcription elongation and mRNA-export function evidence, GO/PubMed/DOI evidence, a nonmechanistic function graph, and a THO subunit-grounding TODO.
2026-09-27T14:43:48Z codex · TIGHTEN_MEREOLOGY — Removed GO:0000346 transcription export complex parthood from the generic GO:0000347 THO complex because GO scopes that context-specific parthood to child term GO:0000445.

Source: data/structures/other/tho_complex.yaml