early endosome lumen

GO:0031905 · Membrane organelle · Subcellular region · Proposed

The volume enclosed by the membrane of an early endosome. [GO:0031905]

Synonyms: early endosomal lumen

Part of: early endosome (GO:0005769)

Xrefs: uniprot.location:SL-0337 — Early endosome lumen

Taxonomic distribution

NCBITaxon:5693 Trypanosoma cruzi — VARIABLE: Trypanosoma cruzi epimastigotes route endocytic cargo through membrane-enclosed early endosome lumens between cytostome entry and reservosome storage. [DOI:10.1078/0171-9335-00112]

NCBITaxon:5693 Trypanosoma cruzi — Kinetoplastid parasite whose epimastigote endocytic cargo traverses membrane-enclosed early endosome lumens before posterior reservosome storage. [DOI:10.1078/0171-9335-00112]

early endosome lumen cargo routing — The early endosome lumen is the membrane-enclosed volume inside the early endosome through which newly internalized endocytic cargo is routed.
- GO:0031905 GO:0031905 defines the early endosome lumen as the volume enclosed by the membrane of an early endosome.
- GO:0005769 GO:0005769 defines early endosomes as receiving incoming material from primary endocytic vesicles for sorting toward recycling or degradation pathways.
- DOI:10.1078/0171-9335-00112 Porto-Carreiro et al. 2000 traced T. cruzi epimastigote cargo through an early endosomal network before reservosome storage.

The early endosome lumen is the bounded internal volume of an early endosome.

Subject	Predicate	Object	Evidence
early endosome lumen	is a	endosome lumen	`uniprot.location:SL-0337` — Early endosome lumen UniProt SL-0337 places the early endosome lumen under endosome lumen. `GO:0031904` GO:0031904 identifies the broader endosome lumen class.
early endosome lumen	is part of	early endosome	`GO:0031905` GO:0031905 defines the early endosome lumen as the volume enclosed by the membrane of an early endosome.
early endosome membrane	bounds	early endosome lumen	`GO:0031901` GO:0031901 identifies the early endosome membrane. `GO:0031905` GO:0031905 defines the early endosome lumen by enclosure within the membrane of an early endosome.

INTERPRETATION (RESOLVED): Represent the early endosome membrane as the boundary of the early endosome lumen rather than as a lumen component. GO:0031905 denotes the volume enclosed by the membrane of an early endosome, whereas GO:0031901 denotes the surrounding lipid bilayer.

GO:0031905 Gene Ontology cellular-component term for the early endosome lumen.
GO:0031904 Gene Ontology cellular-component term for the broader endosome lumen class.
GO:0005769 Gene Ontology cellular-component term for the early endosome.
GO:0031901 Gene Ontology cellular-component term for the early endosome membrane that bounds the lumen.
uniprot.location:SL-0337 — Early endosome lumen UniProt Subcellular Location entry SL-0337 maps Early endosome lumen to GO:0031905 and places it under Endosome lumen.
DOI:10.1078/0171-9335-00112 Porto-Carreiro et al. 2000, Trypanosoma cruzi epimastigote endocytic pathway: cargo enters the cytostome and passes through an early endosomal network before storage in reservosomes, European Journal of Cell Biology.

2026-09-22T17:20:24Z codex · CREATED_RECORD — Scaffolded by scripts/new_record.py
2026-09-22T17:21:08Z codex · EXPANDED_RECORD — Added intracellular-organelle-lumen parentage, early-endosome parthood, an early endosomal lumen synonym, UniProt SL-0337 xref, Trypanosoma cruzi epimastigote scope, a cargo-compartment function, GO/UniProt/DOI evidence, a nonmechanistic lumen-topology graph, and a resolved lumen-boundary interpretation.
2026-09-22T17:33:20Z codex · ADDRESSED_PR_REVIEW — Addressed PR #1305 review issues #1306, #1307, and #1308 by using GO:0031904 endosome lumen parentage, making the Trypanosoma cruzi notes lumen-specific, renaming the cargo-routing function, and adding an endosome-lumen specialization edge to the topology graph.