ESCRT I complex

GO:0000813 · Other · Multiprotein complex · Proposed

An endosomal sorting complex required for transport. It consists of the class E vacuolar protein sorting (Vps) proteins and interacts with ubiquitinated cargoes. [GO:0000813]

Synonyms: ESCRT-I complex; endosomal sorting complex required for transport

Part of: endosome membrane (GO:0010008)

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
Vps23 ESCRT-I subunit	Protein	part of	Reviewed label only (reviewed name; no accession asserted)	VPS23	UNKNOWN	Vps23 core constituent of the yeast ESCRT-I cargo-sorting complex. `PMID:11511343` Katzmann, Babst and Emr 2001 characterized Vps23 as one of three Saccharomyces cerevisiae ESCRT-I subunits in a 350 kDa complex needed for ubiquitin-dependent MVB sorting. `DOI:10.1083/jcb.200302136` Katzmann, Stefan, Babst and Emr 2003 described ESCRT-I as the Vps23, Vps28 and Vps37 complex while testing how Vps27 recruits it to yeast endosomal membranes.
Vps28 ESCRT-I subunit	Protein	part of	Reviewed label only (reviewed name; no accession asserted)	VPS28	UNKNOWN	Vps28 core constituent of the yeast ESCRT-I cargo-sorting complex. `PMID:11511343` Katzmann, Babst and Emr 2001 characterized Vps28 as one of three Saccharomyces cerevisiae ESCRT-I subunits in a 350 kDa complex needed for ubiquitin-dependent MVB sorting. `DOI:10.1083/jcb.200302136` Katzmann, Stefan, Babst and Emr 2003 described ESCRT-I as the Vps23, Vps28 and Vps37 complex while testing how Vps27 recruits it to yeast endosomal membranes.
Vps37 ESCRT-I subunit	Protein	part of	Reviewed label only (reviewed name; no accession asserted)	VPS37	UNKNOWN	Vps37 core constituent of the yeast ESCRT-I cargo-sorting complex. `PMID:11511343` Katzmann, Babst and Emr 2001 characterized Vps37 as one of three Saccharomyces cerevisiae ESCRT-I subunits in a 350 kDa complex needed for ubiquitin-dependent MVB sorting. `DOI:10.1083/jcb.200302136` Katzmann, Stefan, Babst and Emr 2003 described ESCRT-I as the Vps23, Vps28 and Vps37 complex while testing how Vps27 recruits it to yeast endosomal membranes.

Taxonomic distribution

NCBITaxon:4932 Saccharomyces cerevisiae — COMMON: Budding yeast uses Vps23, Vps28 and Vps37 as the ESCRT-I complex during ubiquitin-dependent sorting into multivesicular bodies. [PMID:11511343]

Canonical examples

NCBITaxon:4932 Saccharomyces cerevisiae — Genetic and biochemical model in which Katzmann, Babst and Emr identified Vps23, Vps28 and Vps37 as ESCRT-I subunits required for MVB cargo sorting. [PMID:11511343]

Functions

multivesicular body sorting pathway GO:0071985 — ESCRT-I acts early in the endosomal MVB pathway to help sort ubiquitinated membrane cargo into multivesicular-body vesicles.
- GO:0071985 GO:0071985 denotes the vesicle-mediated transport pathway that moves ubiquitylated transmembrane proteins into multivesicular-body luminal vesicles.
- PMID:11511343 Katzmann, Babst and Emr 2001 identified ESCRT-I as a conserved yeast complex that recognizes ubiquitinated MVB cargo and is required for MVB-vesicle sorting.

Mechanism graphs

ESCRT-I sorts ubiquitinated cargo in yeast MVBs (FUNCTION)

In Saccharomyces cerevisiae, Vps23, Vps28 and Vps37 form ESCRT-I, which is recruited by Vps27 and acts in sorting ubiquitinated cargo into the multivesicular-body pathway.

Subject	Predicate	Object	Evidence
Vps23 ESCRT-I subunit	is part of	ESCRT I complex	`PMID:11511343` Katzmann, Babst and Emr 2001 characterized Vps23 as a yeast ESCRT-I subunit.
Vps28 ESCRT-I subunit	is part of	ESCRT I complex	`PMID:11511343` Katzmann, Babst and Emr 2001 characterized Vps28 as a yeast ESCRT-I subunit.
Vps37 ESCRT-I subunit	is part of	ESCRT I complex	`PMID:11511343` Katzmann, Babst and Emr 2001 characterized Vps37 as a yeast ESCRT-I subunit.
Vps27 endosomal ESCRT-I recruiter	recruits	ESCRT I complex	`DOI:10.1083/jcb.200302136` Katzmann, Stefan, Babst and Emr 2003 found that Vps27 recruits ESCRT-I to endosomes.
ESCRT I complex	is recruited to	endosome membrane	`DOI:10.1083/jcb.200302136` Katzmann, Stefan, Babst and Emr 2003 found that Vps27 recruits ESCRT-I to yeast endosomal membranes.
ESCRT I complex	acts on	ubiquitinated MVB cargo	`PMID:11511343` Katzmann, Babst and Emr 2001 characterized ESCRT-I as recognizing ubiquitinated MVB cargo through the conserved UBC-like domain in Vps23.
ESCRT I complex	participates in	multivesicular body sorting pathway	`PMID:11511343` Katzmann, Babst and Emr 2001 showed that ESCRT-I function is required for sorting cargo into MVB vesicles.

Discussions

CURATION_TODO (OPEN): Resolve exact source-neutral InterPro or Pfam groundings for the Vps23, Vps28 and Vps37 ESCRT-I subunit classes. This first ESCRT-I complex record records the named Saccharomyces cerevisiae Vps23, Vps28 and Vps37 subunits without asserting paralogy boundaries or a single InterPro/Pfam family unless those identifiers are reviewed exactly.
CURATION_TODO (OPEN): Evaluate Mvb12-family and other lineage-specific ESCRT-I subunits before completing the curated component list. This first record starts with the Vps23/Vps28/Vps37 core identified in 2001. Chu et al. 2006 and Curtiss et al. 2007 later identified Mvb12 as an additional yeast ESCRT-I subunit, so Mvb12-family and other lineage-specific components need a dedicated source review before they are added or excluded.
CURATION_TODO (RESOLVED): Do not model Vps27 as a constituent component of ESCRT-I. Vps27 recruits ESCRT-I to endosomal membranes during MVB sorting and is therefore upstream of the constituent Vps23/Vps28/Vps37 ESCRT-I component list in this first record.

Evidence

GO:0000813 Gene Ontology cellular-component term for ESCRT I complex.
GO:0036452 Gene Ontology cellular-component parent term for the ESCRT complex class.
GO:0010008 Gene Ontology cellular-component term for the endosome membrane.
GO:0071985 Gene Ontology biological-process term for the multivesicular body sorting pathway.
PMID:11511343 Katzmann, Babst and Emr 2001, Ubiquitin-Dependent Sorting into the Multivesicular Body Pathway Requires the Function of a Conserved Endosomal Protein Sorting Complex, ESCRT-I, Cell.
DOI:10.1083/jcb.200302136 Katzmann, Stefan, Babst and Emr 2003, Vps27 recruits ESCRT machinery to endosomes during MVB sorting, Journal of Cell Biology.
DOI:10.1016/j.devcel.2011.05.015 Henne, Buchkovich and Emr 2011, The ESCRT Pathway, Developmental Cell.

Curation history

2026-09-16T15:34:02Z codex · CREATED_RECORD — Scaffolded by scripts/new_record.py
2026-09-16T15:35:04Z codex · EXPANDED_RECORD — Added ESCRT-I synonymy, GO parentage and endosome membrane parthood, reviewed-label-only Vps23, Vps28 and Vps37 core subunits, Saccharomyces scope, an MVB sorting function, GO/DOI evidence, a nonmechanistic yeast MVB cargo-sorting graph, a subunit-grounding TODO, and a resolved Vps27 boundary decision.
2026-09-16T15:35:35Z codex · REFINED_RECORD — Connected the ESCRT-I function graph to the endosome membrane with Katzmann et al. 2003 Vps27-dependent recruitment evidence.
2026-09-16T15:47:08Z codex · ADDRESSED_PR_REVIEW — Resolved PR #1106 review issue #1107 by adding an open TODO that explicitly tracks later Mvb12-family and lineage-specific ESCRT-I subunits instead of silently omitting them from the first Vps23/Vps28/Vps37 core record.
2026-09-21T08:41:49Z codex · REPLACED_UNREADABLE_EVIDENCE — Resolved #1224 by routing Katzmann, Babst and Emr 2001 ESCRT-I evidence through reachable PMID:11511343 instead of the unreadable Cell DOI.

Source: data/structures/other/escrt_i_complex.yaml