TORC1 complex

GO:0031931 · Other · Multiprotein complex · Proposed

A protein complex that contains at least TOR (target of rapamycin) and Raptor (regulatory-associated protein of TOR), or orthologs of, in complex with other signaling components. Mediates the phosphorylation and activation of S6K. In Saccharomyces, the complex contains Kog1p, Lst8p, Tco89p, and either Tor1p or Tor2p. [GO:0031931]

Synonyms: TORC1; TOR complex 1; rapamycin and nutrient-sensitive TOR complex; nutrient sensitive complex

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
TOR kinase TORC1 subunit	Protein	part of	Reviewed label only (reviewed name; no accession asserted)	TOR1, TOR2	UNKNOWN	Alternate catalytic TOR kinase subunit supplied by Tor1 or Tor2 in the budding-yeast TORC1 complex. `GO:0031931` Gene Ontology cellular-component term for the TORC1 complex. `DOI:10.1016/s1097-2765(02)00636-6` Loewith et al. 2002 separated budding-yeast TOR into two complexes and assigned TORC1 to the rapamycin-sensitive growth-control branch.
Kog1 Raptor-family TORC1 subunit	Protein	part of	Reviewed label only (reviewed name; no accession asserted)	KOG1	UNKNOWN	Raptor-family TORC1 constituent that joins the TOR kinase, Lst8 and Tco89 in budding-yeast TORC1. `GO:0031931` Gene Ontology cellular-component term for the TORC1 complex. `DOI:10.1016/s1097-2765(02)00636-6` Loewith et al. 2002 separated budding-yeast TOR into two complexes and assigned TORC1 to the rapamycin-sensitive growth-control branch.
Lst8 TORC1/TORC2 beta-propeller subunit	Protein	part of	Reviewed label only (reviewed name; no accession asserted)	LST8	UNKNOWN	Beta-propeller subunit represented here in its TORC1 constituent context. `GO:0031931` Gene Ontology cellular-component term for the TORC1 complex. `DOI:10.1016/s1097-2765(02)00636-6` Loewith et al. 2002 separated budding-yeast TOR into two complexes and assigned TORC1 to the rapamycin-sensitive growth-control branch.
Tco89 TORC1-specific subunit	Protein	part of	Reviewed label only (reviewed name; no accession asserted)	TCO89	UNKNOWN	Budding-yeast TORC1 component associated with the Kog1/Lst8/Tor complex. `GO:0031931` Gene Ontology cellular-component term for the TORC1 complex. `DOI:10.1074/jbc.M313062200` Reinke et al. 2004 identified Tco89p as a Saccharomyces cerevisiae TORC1 component.

Taxonomic distribution

NCBITaxon:4932 Saccharomyces cerevisiae — VARIABLE: Budding yeast is the curated model for TORC1 complexes containing Kog1, Lst8, Tco89 and either Tor1 or Tor2. [GO:0031931]

Canonical examples

NCBITaxon:4932 Saccharomyces cerevisiae — Yeast model in which the rapamycin-sensitive TORC1 complex was separated from TORC2. [DOI:10.1016/s1097-2765(02)00636-6]

Functions

TORC1 signaling GO:0038202 — The TORC1 complex mediates nutrient- and rapamycin-sensitive growth-control signaling in budding yeast.
- GO:0038202 Gene Ontology biological-process term for TORC1 signaling.
- GO:0031931 Gene Ontology cellular-component term for the TORC1 complex.
- DOI:10.1016/s1097-2765(02)00636-6 Loewith et al. 2002 separated budding-yeast TOR into two complexes and assigned TORC1 to the rapamycin-sensitive growth-control branch.

Mechanism graphs

Yeast TORC1 complex mediates TORC1 signaling (FUNCTION)

In Saccharomyces cerevisiae, Kog1, Lst8, Tco89 and an alternate Tor1/Tor2 catalytic subunit form the rapamycin-sensitive complex that mediates TORC1 signaling.

Subject	Predicate	Object	Evidence
TOR kinase TORC1 subunit	is part of	TORC1 complex	`GO:0031931` Gene Ontology cellular-component term for the TORC1 complex. `DOI:10.1016/s1097-2765(02)00636-6` Loewith et al. 2002 separated budding-yeast TOR into two complexes and assigned TORC1 to the rapamycin-sensitive growth-control branch.
Kog1 Raptor-family TORC1 subunit	is part of	TORC1 complex	`GO:0031931` Gene Ontology cellular-component term for the TORC1 complex. `DOI:10.1016/s1097-2765(02)00636-6` Loewith et al. 2002 separated budding-yeast TOR into two complexes and assigned TORC1 to the rapamycin-sensitive growth-control branch.
Lst8 TORC1/TORC2 beta-propeller subunit	is part of	TORC1 complex	`GO:0031931` Gene Ontology cellular-component term for the TORC1 complex. `DOI:10.1016/s1097-2765(02)00636-6` Loewith et al. 2002 separated budding-yeast TOR into two complexes and assigned TORC1 to the rapamycin-sensitive growth-control branch.
Tco89 TORC1-specific subunit	is part of	TORC1 complex	`GO:0031931` Gene Ontology cellular-component term for the TORC1 complex. `DOI:10.1074/jbc.M313062200` Reinke et al. 2004 identified Tco89p as a Saccharomyces cerevisiae TORC1 component.
TORC1 complex	mediates	TORC1 signaling	`GO:0038202` Gene Ontology biological-process term for TORC1 signaling. `GO:0031931` Gene Ontology cellular-component term for the TORC1 complex. `DOI:10.1016/s1097-2765(02)00636-6` Loewith et al. 2002 separated budding-yeast TOR into two complexes and assigned TORC1 to the rapamycin-sensitive growth-control branch.

Discussions

CURATION_TODO (OPEN): Resolve exact source-neutral InterPro, Pfam, or NCBIfam groundings for the yeast TORC1 Tor, Kog1, Lst8 and Tco89 subunit classes. This first TORC1 record names the yeast protein constituents but leaves family grounding unset until exact source-neutral boundaries for shared TOR/Lst8 classes and Kog1/Tco89 orthology are reviewed.
CURATION_TODO (RESOLVED): Keep TORC2-specific Avo1, Avo2, Avo3/Tsc11, Bit61, Slm1 and Slm2 outside this TORC1 record. GO separates rapamycin-sensitive TORC1 from TORC2 as sibling complexes. Tor2 and Lst8 can occur in yeast TORC2, but Avo1, Avo2, Avo3/Tsc11, Bit61, Slm1 and Slm2 are TORC2-side subunits outside GO:0031931.
CURATION_TODO (RESOLVED): Keep Gtr1-Gtr2, GATOR1/SEACIT, GATOR2/SEACAT and Ragulator/EGO outside this TORC1 constituent record. Gtr1-Gtr2 and its GATOR and Ragulator/EGO control complexes are upstream TORC1-pathway regulators or anchors with their own GO cellular-component identities, not constituents of the TORC1 catalytic complex.

Evidence

GO:0031931 Gene Ontology cellular-component term for the TORC1 complex.
GO:0032991 Gene Ontology cellular-component parent term for protein-containing complexes.
GO:0038202 Gene Ontology biological-process term for TORC1 signaling.
DOI:10.1016/s1097-2765(02)00636-6 Loewith et al. 2002 separated budding-yeast TOR into two complexes and assigned TORC1 to the rapamycin-sensitive growth-control branch.
DOI:10.1074/jbc.M313062200 Reinke et al. 2004 identified Tco89p as a Saccharomyces cerevisiae TORC1 component.

Curation history

2026-09-18T11:09:46Z codex · CREATED_RECORD — Scaffolded by scripts/new_record.py
2026-09-18T11:11:30Z codex · EXPANDED_RECORD — Added TORC1 synonymy, protein-complex parentage, reviewed-label-only yeast Tor/Kog1/Lst8/Tco89 components, Saccharomyces scope, a TORC1 signaling function, GO/DOI evidence, a nonmechanistic TORC1 function graph, and subunit-grounding plus TORC2 and Rag/GATOR/EGO boundary discussions.
2026-09-18T11:11:54Z codex · REFORMATTED_RECORD — Expanded shared YAML evidence aliases into plain repeated mappings.
2026-09-18T11:31:37Z codex · ADDRESSED_PR_REVIEW — #1144: Changed the TORC1-to-TORC1-signaling graph edge from an upstream-regulation predicate to a mediator predicate and tightened the graph wording around the GO:0038202 process.
2026-09-18T11:45:00Z codex · ADDRESSED_PR_REVIEW — #1145: Narrowed the Saccharomyces cerevisiae TORC1 taxonomic-presence qualifier from COMMON to VARIABLE to avoid overclaiming strain-level prevalence from a yeast model annotation.

Source: data/structures/other/torc1_complex.yaml