TIM22 mitochondrial import inner membrane insertion complex

GO:0042721 · Other · Multiprotein complex · Proposed

A multi-subunit mitochondrial inner-membrane complex that mediates insertion of multi-pass inner-membrane precursor proteins carrying internal targeting elements. [GO:0042721]

Synonyms: mitochondrial inner membrane protein insertion complex; Tim22 complex; mitochondrial protein translocase complex

Part of: mitochondrial inner membrane (GO:0005743)

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

Taxonomic distribution

NCBITaxon:4932 Saccharomyces cerevisiae — COMMON: Budding-yeast mitochondria contain a TIM22 inner-membrane translocase that inserts carrier-pathway precursors with internal targeting elements. [DOI:10.1128/MCB.20.4.1187-1193.2000]

Canonical examples

NCBITaxon:4932 Saccharomyces cerevisiae — Budding-yeast model for the TIM22 carrier translocase and for Tim18 function in TIM22-dependent inner-membrane protein insertion. [DOI:10.1128/MCB.20.4.1187-1193.2000]

Functions

protein insertion into mitochondrial inner membrane GO:0045039 — TIM22 mediates the mitochondrial inner-membrane insertion step for multi-pass carrier proteins that carry internal targeting elements.
- GO:0042721 GO:0042721 defines TIM22 as a mitochondrial inner-membrane complex that inserts multi-transmembrane proteins carrying internal targeting elements.
- GO:0045039 GO:0045039 denotes protein insertion into the mitochondrial inner membrane.
- DOI:10.1016/j.cell.2009.08.005 Chacinska et al. 2009 reviewed the TIM22 carrier pathway for hydrophobic mitochondrial inner-membrane proteins with internal targeting signals.
- DOI:10.1128/MCB.20.4.1187-1193.2000 Koehler et al. 2000 identified Tim18 as a budding-yeast TIM22-complex subunit needed for efficient insertion of imported mitochondrial inner-membrane proteins.

Mechanism graphs

TIM22 mediates carrier insertion into the inner membrane (FUNCTION)

TIM22 resides in the mitochondrial inner membrane and inserts imported multi-pass carrier proteins into that membrane.

Subject	Predicate	Object	Evidence
TIM22 mitochondrial import inner membrane insertion complex	is part of	mitochondrial inner membrane	`GO:0042721` GO:0042721 defines TIM22 as a complex embedded in the mitochondrial inner membrane.
TIM22 mitochondrial import inner membrane insertion complex	supports	protein insertion into mitochondrial inner membrane	`GO:0042721` GO:0042721 grounds TIM22 as the mitochondrial inner-membrane insertion complex for multi-transmembrane proteins with internal targeting elements. `DOI:10.1016/j.cell.2009.08.005` Chacinska et al. 2009 reviewed the TIM22 carrier pathway for protein insertion into the mitochondrial inner membrane.

Discussions

CURATION_TODO (OPEN): Resolve exact source-neutral family groundings and stable TIM22 versus small-TIM carrier-pathway boundaries before adding Tim rows. GO exactly grounds the TIM22 complex itself and names the yeast integral membrane subunits plus the peripheral small TIM complex in its definition, but this first record leaves Tim22, Tim54, Tim18, Sdh3, and small-TIM chaperone rows unasserted until exact source-neutral family groundings are separated from stable TIM22 constituents versus carrier-pathway chaperone roles.

Evidence

GO:0042721 Gene Ontology cellular-component term for the TIM22 mitochondrial import inner membrane insertion complex.
GO:0098800 Gene Ontology cellular-component parent term for inner mitochondrial membrane protein complexes.
GO:0005743 Gene Ontology cellular-component term for the mitochondrial inner membrane that contains TIM22.
GO:0045039 Gene Ontology biological-process term for protein insertion into the mitochondrial inner membrane.
DOI:10.1016/j.cell.2009.08.005 Chacinska et al. 2009, 'Importing mitochondrial proteins: machineries and mechanisms', Cell.
DOI:10.1128/MCB.20.4.1187-1193.2000 Koehler et al. 2000, 'Tim18p, a new subunit of the TIM22 complex that mediates insertion of imported proteins into the yeast mitochondrial inner membrane', Molecular and Cellular Biology.

Curation history

2026-09-18T17:41:46Z codex · CREATED_RECORD — Scaffolded by scripts/new_record.py
2026-09-18T17:42:27Z codex · EXPANDED_RECORD — Added GO synonymy, inner-mitochondrial-membrane protein-complex parentage, mitochondrial-inner-membrane parthood, Saccharomyces scope, inner-membrane insertion function evidence, a nonmechanistic TIM22 insertion graph, and a TIM22 subunit-boundary TODO.
2026-09-18T17:52:32Z codex · ADDRESS_REVIEW — Resolved #1177 by narrowing the TIM22 graph scope and subunit TODO to the cited yeast integral membrane subunits and small TIM chaperone boundary.

Source: data/structures/other/tim22_mitochondrial_import_inner_membrane_insertion_complex.yaml