contractile vacuole complex

GO:0062159 · Membrane organelle · Other · Proposed

A non-membrane-bounded organelle of eukaryotic cells, especially Protozoa, that fills with water from the cytoplasm and then discharges this externally. One of its functions is osmoregulatory. [GO:0062159]

Synonyms: CVC

Has part: contractile vacuole (GO:0000331); spongiome (GO:0062160)

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

Taxonomic distribution

NCBITaxon:2759 Eukaryota — RARE: Contractile vacuole complexes occur patchily in unicellular eukaryotes, especially freshwater and soil protists, rather than throughout Eukaryota. [DOI:10.1016/j.ejop.2024.126078]

Canonical examples

NCBITaxon:44689 Dictyostelium discoideum — Amoebozoan model in which the contractile-vacuole complex was biochemically resolved into bladder and spongiome membranes. [PMID:8294479]
NCBITaxon:44030 Paramecium multimicronucleatum — Ciliate model in which the decorated-spongiome radial arms of the contractile-vacuole complex were connected to fluid segregation. [DOI:10.1242/jeb.205.20.3261]

Functions

osmoregulatory water expulsion — The contractile vacuole complex collects excess cytosolic water and periodically discharges it outside the cell to maintain osmotic balance.
- GO:0062159 GO:0062159 defines the contractile vacuole complex as an organelle that fills with cytoplasmic water, discharges it externally, and functions in osmoregulation.
- DOI:10.1016/B978-0-12-407695-2.00002-0 Docampo et al. 2013 review acidocalcisome and contractile-vacuole osmoregulation in protists.

Mechanism graphs

Contractile vacuole complex coordinates water collection and discharge (FUNCTION)

The contractile vacuole complex includes a central contractile vacuole and a tubular or vesicular spongiome subnetwork that together drive osmoregulatory water expulsion.

Subject	Predicate	Object	Evidence
contractile vacuole	is part of	contractile vacuole complex	`GO:0000331` GO:0000331 is part_of GO:0062159 contractile vacuole complex.
spongiome	is part of	contractile vacuole complex	`GO:0062160` GO:0062160 defines the spongiome as part of the contractile vacuole complex. `PMID:8294479` Nolta and Steck 1994 purified a bipartite Dictyostelium contractile-vacuole complex with separable bladder and spongiome membranes.
contractile vacuole complex	carries out	osmoregulatory water expulsion	`GO:0062159` GO:0062159 defines the contractile vacuole complex by water filling, external discharge, and osmoregulatory function. `DOI:10.1016/B978-0-12-407695-2.00002-0` Docampo et al. 2013 review contractile vacuole complex osmoregulation in protists.

Discussions

INTERPRETATION (RESOLVED): Keep V-ATPase and aquaporin molecular components on the contractile vacuole and spongiome child records instead of duplicating them on this complex parent. This record represents the contractile vacuole complex as a parent organelle with a central vacuole and spongiome; pump, channel, and V-ATPase localization details are more precisely curated on those substructure records.

Evidence

GO:0062159 Gene Ontology cellular-component term for the contractile vacuole complex.
GO:0000331 Gene Ontology cellular-component term for the contractile vacuole.
GO:0062160 Gene Ontology cellular-component term for spongiome.
GO:0043232 Gene Ontology cellular-component parent term for intracellular membraneless organelles.
PMID:8294479 Nolta and Steck 1994, Isolation and initial characterization of the bipartite contractile vacuole complex from Dictyostelium discoideum, Journal of Biological Chemistry.
DOI:10.1242/jeb.205.20.3261 Gronlien et al. 2002, Relationship between the membrane potential of the contractile vacuole complex and its osmoregulatory activity in Paramecium multimicronucleatum, Journal of Experimental Biology.
DOI:10.1016/B978-0-12-407695-2.00002-0 Docampo et al. 2013 review acidocalcisome and contractile-vacuole osmoregulation in protists.
DOI:10.1016/j.ejop.2024.126078 More et al. 2024, Contractile vacuoles: a rapidly expanding (and occasionally diminishing?) understanding, European Journal of Protistology.

Curation history

2026-09-23T21:46:07Z claude-code · CREATED_RECORD — Scaffolded by scripts/new_record.py
2026-09-23T21:46:49Z claude-code · EXPANDED_RECORD — Added GO synonymy, membraneless-organelle parentage, contractile vacuole and spongiome has_part links, Dictyostelium and Paramecium examples, an osmoregulatory function, DOI/PMID/GO evidence, a nonmechanistic contractile-vacuole-complex graph, and a child-boundary decision.

Source: data/structures/membrane_organelle/contractile_vacuole_complex.yaml