cytostome

GO:0031910 · Other · Other · Proposed

Stable, specialized structure for the ingestion of food by the cell into phagosomes. [GO:0031910]

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

Taxonomic distribution

• NCBITaxon:5693 Trypanosoma cruzi — VARIABLE: The cytostome-cytopharynx complex has been structurally characterized in T. cruzi epimastigotes. [DOI:10.1242/jcs.135491]

Canonical examples

• NCBITaxon:5693 Trypanosoma cruzi — Kinetoplastid parasite whose epimastigote cytostome-cytopharynx complex has been reconstructed in three dimensions. [DOI:10.1242/jcs.135491]

Functions

• endocytic cargo uptake — The T. cruzi epimastigote cytostome admits extracellular macromolecular cargo into the endocytic route that passes through an early endosomal network before reservosome storage.
  • DOI:10.1078/0171-9335-00112 Porto-Carreiro et al. 2000 traced endocytic cargo entering through the cytostome and later reaching reservosomes in T. cruzi epimastigotes.

Mechanism graphs

Cytostome entry feeds the reservosome endocytic route (FUNCTION)

In T. cruzi epimastigotes, extracellular cargo enters through the cytostome before moving through the endocytic pathway toward posterior reservosomes.

Discussions

• CURATION_TODO (OPEN): Resolve exact source-neutral family groundings for cytostome-cytopharynx localized proteins before adding molecular components. The first known T. cruzi cytostome-cytopharynx proteins were identified by localization rather than by a curated exact InterPro, Pfam, NCBIfam or UniProt family boundary in this pass.
• CURATION_TODO (OPEN): Decide whether the cytopharynx or the full cytostome-cytopharynx complex needs a separate record after curating component-level evidence. GO:0031910 exactly denotes the cytostome opening, while the T. cruzi literature usually characterizes the larger cytostome-cytopharynx complex; a future boundary review should split a named cytopharynx record only if it can carry its own identifier, composition and mechanism.

Evidence

• GO:0031910 Gene Ontology cellular-component term for cytostome.
• DOI:10.1006/expr.1999.4419 Okuda et al. 1999, The cytostome of Trypanosoma cruzi epimastigotes is associated with the flagellar complex, Experimental Parasitology.
• 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:10.1242/jcs.135491 Alcantara et al. 2014, The three-dimensional structure of the cytostome-cytopharynx complex of Trypanosoma cruzi epimastigotes, Journal of Cell Science.
• DOI:10.3389/fcimb.2019.00445 Chasen et al. 2020, Identification and Localization of the First Known Proteins of the Trypanosoma cruzi Cytostome Cytopharynx Endocytic Complex, Frontiers in Cellular and Infection Microbiology.

Curation history

• 2026-09-13T10:00:45Z codex · CREATED_RECORD — Scaffolded by scripts/new_record.py
• 2026-09-13T10:01:45Z codex · EXPANDED_RECORD — Added plasma-membrane parentage, Trypanosoma cruzi taxonomic scope, a T. cruzi cytostome-cytopharynx canonical example, endocytic cargo uptake evidence, a nonmechanistic cytostome-to-reservosome graph, and curation TODOs for cytostome protein grounding and cytopharynx boundaries.
• 2026-09-13T10:08:18Z codex · ADDRESS_REVIEW — Addressed PR #770 review issue #771 by narrowing the Trypanosoma cruzi distribution note to structural characterization in epimastigotes and removing unsupported developmental-regulation wording.

Source: data/structures/other/cytostome.yaml