reservosome

cellstructuremech:reservosome · Membrane organelle · Membrane bounded organelle · Proposed

A posterior, membrane-bounded endocytic organelle in Trypanosoma cruzi epimastigotes that receives internalized macromolecular cargo. [DOI:10.1017/S0031182004005797]

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

Components

Component	Type	Part of / acts on	Grounding	Role
reservosome membrane	Lipid	part of		Membrane boundary of the posterior acidic compartment that separates reservosome contents from the T. cruzi cytosol. `DOI:10.1017/S0031182004005797` Figueiredo et al. 2004 described reservosomes as large membrane-bound organelles in T. cruzi epimastigotes.
endocytosed protein and lipid cargo	Other	part of	Reviewed label only (reviewed name; no accession asserted)	Proteins and lipids internalized through the endocytic pathway and stored inside reservosomes. `DOI:10.1078/0171-9335-00112` Porto-Carreiro et al. 2000 traced endocytic cargo entering the cytostome and reaching reservosomes.
cruzipain	Protein	part of	Reviewed label only (reviewed name; no accession asserted)	Major lysosomal cysteine proteinase concentrated in the reservosome lumen. `DOI:10.1002/pmic.200800730` Sant'Anna et al. 2009 identified hydrolases, including cruzipain, in the reservosome proteome.

Taxonomic distribution

NCBITaxon:5693 Trypanosoma cruzi — VARIABLE: Reservosomes are posterior membrane-bounded organelles detected in T. cruzi epimastigotes and absent from amastigotes and trypomastigotes. [DOI:10.1017/S0031182004005797]

Canonical examples

NCBITaxon:5693 Trypanosoma cruzi — Kinetoplastid parasite whose free-swimming epimastigotes carry posterior, transferrin-labelled reservosomes. [DOI:10.1017/S0031182004005797]

Functions

endocytic cargo storage — Reservosomes store proteins and lipids delivered by the T. cruzi epimastigote endocytic pathway.
- DOI:10.1078/0171-9335-00112 Porto-Carreiro et al. 2000 showed that endocytic cargo passes from the cytostome through an early endosomal network before storage in reservosomes.
- DOI:10.1017/S0031182004005797 Figueiredo et al. 2004 reviewed reservosomes as endocytic compartments in T. cruzi epimastigotes.
reservosome hydrolase-associated proteolysis — Reservosomes concentrate lysosomal hydrolases, including cruzipain, in a proteome associated with protein degradation and regulation.
- DOI:10.1002/pmic.200800730 Sant'Anna et al. 2009 identified cruzipain and other lysosomal hydrolases in purified reservosomes and discussed reservosomes as a major protein degradation and regulation site.

Mechanism graphs

Reservosomes store cargo and contain hydrolases (FUNCTION)

Cargo entering through the cytostome-cytopharynx reaches the reservosome, where internalized protein and lipid cargo is stored alongside a hydrolase pool that includes cruzipain.

Subject	Predicate	Object	Evidence
cytostome-cytopharynx	delivers	endocytosed protein and lipid cargo	`DOI:10.1078/0171-9335-00112` Porto-Carreiro et al. 2000 traced endocytic cargo from the cytostome through the endosomal pathway.
endocytosed protein and lipid cargo	accumulates in	reservosome	`DOI:10.1078/0171-9335-00112` Porto-Carreiro et al. 2000 placed reservosomes at the storage end of the T. cruzi epimastigote endocytic pathway.
cruzipain	localizes to	reservosome	`DOI:10.1002/pmic.200800730` Sant'Anna et al. 2009 detected cruzipain and other hydrolases in purified reservosomes.
cruzipain	is associated with	reservosome cargo proteolysis	`DOI:10.1002/pmic.200800730` Sant'Anna et al. 2009 detected cruzipain and other lysosomal hydrolases in purified reservosomes and discussed protein degradation and regulation as a reservosome role.

Discussions

CURATION_TODO (OPEN): Resolve exact cruzipain isoforms, chagasin, proton pumps and other reservosome-localized markers before expanding the proteolysis graph. The purified reservosome proteome includes many proteins, but this first pass curates only the broad cruzipain pool and leaves isoform-level and inhibitor boundaries for a targeted grounding review.

Evidence

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.
DOI:10.1017/S0031182004005797 Figueiredo et al. 2004, Reservosome: an endocytic compartment in epimastigote forms of the protozoan Trypanosoma cruzi, Parasitology.
DOI:10.1002/pmic.200800730 Sant'Anna et al. 2009, Subcellular proteomics of Trypanosoma cruzi reservosomes, Proteomics.

Curation history

2026-09-10T11:53:13Z claude · CREATED_RECORD — Scaffolded by scripts/new_record.py
2026-09-10T11:53:54Z claude · EXPANDED_RECORD — Added reservosome membrane, endocytic cargo and cruzipain components, Trypanosoma cruzi epimastigote scope, endocytic cargo storage and acidic proteolysis functions, reservosome literature evidence, an endocytic storage graph and a cruzipain grounding TODO.
2026-09-10T11:54:24Z claude · REFINED_GRAPH — Softened the terminal cruzipain edge so the nonmechanistic graph links the reservosome hydrolase pool to degraded cargo rather than claiming an exact cruzipain-substrate relationship.
2026-09-10T12:03:55Z claude · ADDRESSED_PR_REVIEW — Addressed PR #359 review issues #360 and #361 by adding GO:0043231 as the reservosome's broader parent and replacing the vague degraded-cargo terminal state with an explicit cargo-proteolysis process.
2026-09-21T16:59:24Z codex · REPLACE_UNREADABLE_EVIDENCE — Resolved #1249 by replacing unreadable reservosome review evidence with readable Figueiredo 2004 and Sant'Anna 2009 support and narrowing acidic proteolysis claims to hydrolase/proteome claims covered by Sant'Anna 2009.

Source: data/structures/membrane_organelle/reservosome.yaml