endosome lumen

GO:0031904 · Membrane organelle · Subcellular region · Proposed

The volume enclosed by the membrane of an endosome. [GO:0031904]

Part of: endosome (GO:0005768)

Taxonomic distribution

NCBITaxon:4932 Saccharomyces cerevisiae — COMMON: Budding yeast endosomal multivesicular bodies form lumenal intraluminal vesicles during ESCRT-dependent cargo sorting. [PMID:11511343]

NCBITaxon:4932 Saccharomyces cerevisiae — Genetic model for ESCRT-dependent delivery of ubiquitinated endosomal membrane cargo into the multivesicular-body lumen. [PMID:11511343]

multivesicular body sorting pathway GO:0071985 — The endosome lumen receives intraluminal vesicles and their membrane cargo during ESCRT-dependent multivesicular-body sorting.
- GO:0005771 GO:0005771 defines multivesicular bodies as endosomes with internal vesicles formed by invagination of the limiting endosomal membrane.
- PMID:11511343 Katzmann, Babst and Emr 2001 identified ESCRT-I as a conserved yeast endosomal protein-sorting complex needed for ubiquitin-dependent MVB cargo sorting.

The endosome membrane bounds the endosome lumen whose multivesicular-body lumen specialization receives intraluminal vesicles during MVB sorting.

Subject	Predicate	Object	Evidence
endosome lumen	is part of	endosome	`GO:0031904` GO:0031904 defines the endosome lumen as the volume enclosed by the membrane of an endosome.
multivesicular body lumen	is a	endosome lumen	`uniprot.location:SL-0340` — Multivesicular body lumen UniProt SL-0340 places the multivesicular body lumen under endosome lumen.
endosome membrane	bounds	endosome lumen	`GO:0031904` GO:0031904 defines the endosome lumen by the surrounding endosome membrane. `GO:0010008` GO:0010008 identifies the endosome-bounding lipid bilayer.
multivesicular body	is a	endosome	`GO:0005771` GO:0005771 defines multivesicular bodies as endosomes that contain internal vesicles formed from the limiting endosomal membrane.
multivesicular body intraluminal vesicle	is contained in	multivesicular body lumen	`GO:0005771` GO:0005771 defines multivesicular bodies by internal vesicles formed from invagination of the limiting endosomal membrane. `uniprot.location:SL-0340` — Multivesicular body lumen UniProt SL-0340 identifies the internal multivesicular body lumen.

INTERPRETATION (RESOLVED): Represent the endosome membrane as the boundary of the endosome lumen rather than as a lumen component. GO:0031904 denotes the volume enclosed by the endosome membrane, whereas GO:0010008 denotes the surrounding lipid bilayer.

GO:0031904 Gene Ontology cellular-component term for the endosome lumen.
GO:0070013 Gene Ontology cellular-component parent term for intracellular organelle lumen.
GO:0005768 Gene Ontology cellular-component term for endosome.
GO:0010008 Gene Ontology cellular-component term for the endosome membrane that bounds the lumen.
GO:0005771 Gene Ontology cellular-component term for the multivesicular body.
uniprot.location:SL-0340 — Multivesicular body lumen UniProt Subcellular Location entry SL-0340 identifies the multivesicular body lumen as an endosome-lumen specialization.
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:10.1016/j.devcel.2011.05.015 Henne, Buchkovich and Emr 2011, The ESCRT Pathway, Developmental Cell.

2026-09-15T20:10:50Z codex · CREATED_RECORD — Scaffolded by scripts/new_record.py
2026-09-15T20:11:48Z codex · EXPANDED_RECORD — Added organelle-lumen parentage, endosome parthood, budding-yeast MVB sorting scope, GO/DOI evidence, a nonmechanistic endosome lumen topology graph, and a resolved lumen-boundary interpretation.
2026-09-15T20:24:39Z codex · ADDRESS_REVIEW — Resolved #1022 by routing intraluminal vesicle containment through the multivesicular body lumen specialization and resolved #1023 by removing the unused ESCRT-III DOI from record-level evidence.
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.
2026-09-23T08:14:39Z codex · LINKED_INTRALUMINAL_VESICLE_RECORD — Grounded the multivesicular-body intraluminal vesicle graph node to cellstructuremech:multivesicular_body_intraluminal_vesicle.