acidocalcisome lumen

GO:0033985 · Membrane organelle · Subcellular region · Proposed

The acidocalcisome compartment bounded by the acidocalcisomal membrane. [GO:0033985]

Synonyms: acidocalcisomal lumen

Part of: acidocalcisome (GO:0020022)

Xrefs: uniprot.location:SL-0316 — Acidocalcisome lumen

Taxonomic distribution

NCBITaxon:2 Bacteria — VARIABLE: Acidocalcisome-like compartments have been characterized in bacteria, but they are not universal across bacteria. [DOI:10.1038/nrmicro1097]
NCBITaxon:2759 Eukaryota — VARIABLE: Acidocalcisomes occur across diverse unicellular eukaryotes and metazoan cell types, so the lumen is present in the subset of eukaryotic cells that carry this organelle. [DOI:10.1128/MMBR.00042-23]

NCBITaxon:358 Agrobacterium tumefaciens — Bacterial species whose membrane-bounded, calcium- and polyphosphate-rich acidocalcisome-like volutin granules establish a lumenal storage compartment. [DOI:10.1074/jbc.M304548200]

The acidocalcisome lumen is the internal compartment of the acidocalcisome bounded by the acidocalcisome membrane.

Subject	Predicate	Object	Evidence
acidocalcisome lumen	is part of	acidocalcisome	`GO:0033985` GO:0033985 is the acidocalcisome lumen cellular-component term. `uniprot.location:SL-0316` — Acidocalcisome lumen UniProt SL-0316 places the lumen under the acidocalcisome subcellular location. `GO:0020022` GO:0020022 identifies the containing acidocalcisome organelle.
acidocalcisome membrane	bounds	acidocalcisome lumen	`GO:0033985` GO:0033985 defines the acidocalcisome lumen as the compartment bounded by the acidocalcisomal membrane. `GO:0033102` GO:0033102 defines the acidocalcisome membrane as the lipid bilayer surrounding an acidocalcisome. `uniprot.location:SL-0316` — Acidocalcisome lumen UniProt SL-0316 describes the acidocalcisome lumen as bounded by the acidocalcisomal membrane. `uniprot.location:SL-0003` — Acidocalcisome membrane UniProt SL-0003 maps the acidocalcisome membrane to GO:0033102.

INTERPRETATION (RESOLVED): Keep acidocalcisome polyphosphate, bound cations, proton pumps, and cation transporters on the whole-organelle or membrane records rather than duplicating them as lumen components. GO:0033985 denotes the acidocalcisome compartment bounded by the acidocalcisomal membrane; the existing acidocalcisome record models the organelle's polyphosphate and cation matrix, and the acidocalcisome membrane record models its proton-pump and cation-transporter proteins.

GO:0033985 Gene Ontology cellular-component term for acidocalcisome lumen.
GO:0043233 Gene Ontology cellular-component term for organelle lumen, the broader organelle-enclosed compartment parent.
GO:0020022 Gene Ontology cellular-component term for acidocalcisome.
GO:0033102 Gene Ontology cellular-component term for the acidocalcisome membrane that bounds this lumen.
uniprot.location:SL-0316 — Acidocalcisome lumen UniProt Subcellular Location entry SL-0316 maps directly to GO:0033985, places the acidocalcisome lumen under the acidocalcisome, and lists acidocalcisomal lumen as an exact synonym.
uniprot.location:SL-0003 — Acidocalcisome membrane UniProt Subcellular Location entry SL-0003 maps the bounding acidocalcisome membrane to GO:0033102.
DOI:10.1038/nrmicro1097 Docampo et al. 2005 review acidocalcisomes as acidic, polyphosphate- and cation-rich organelles conserved across bacteria and eukaryotes.
DOI:10.1074/jbc.M304548200 Seufferheld et al. 2003 characterized membrane-bounded acidocalcisome-like volutin granules in bacteria.
DOI:10.1128/MMBR.00042-23 Docampo and Huang 2024 review acidocalcisome cell biology, biochemistry, and physiological roles.

2026-09-12T23:22:45Z codex · CREATED_RECORD — Scaffolded by scripts/new_record.py
2026-09-12T23:23:32Z codex · EXPANDED_RECORD — Added the UniProt SL xref and synonym, organelle-lumen parentage, acidocalcisome parthood, bacterial and eukaryotic distributions, an Agrobacterium example, a nonmechanistic lumen-topology graph, and a resolved interpretation that keeps matrix chemistry on the whole-organelle record.
2026-09-12T23:33:33Z codex · ADDRESS_REVIEW — Resolved #720 by citing GO:0020022 on the parthood edge that points to the containing acidocalcisome.