ventral disc microtubule array

GO:0097593 · Cytoskeleton · Filament · Proposed

A part of the ventral disc of Giardia species (trophozoite stage) consisting of a spiral array of microtubules linked to the ventral membrane. These microtubules form the base of the ventral disc dorsal microribbons that extend nearly perpendicular from the membrane. [GO:0097593]

Synonyms: ventral disc spiral microtubule array; spiral microtubule array; ventral disk microtubule array

Part of: ventral disc (GO:0097597)

Has part: microtubule (GO:0005874)

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

Components

Component	Type	Part of / acts on	Grounding	Genes	Stoichiometry	Essential	Role
alpha- and beta-tubulins	Protein	part of	Reviewed label only (reviewed name; no accession asserted)			UNKNOWN	Tubulin constituents that polymerize into the Giardia ventral-disc microtubules. `GO:0005874` Gene Ontology defines microtubules as tubes of polymeric tubulin. `DOI:10.1371/journal.pone.0043783` Schwartz et al. 2012 used electron tomography to resolve the Giardia ventral-disc microtubule spiral.

Taxonomic distribution

NCBITaxon:5741 Giardia intestinalis — COMMON: Giardia intestinalis is the diplomonad species in which the ventral-disc microtubule spiral was mapped by electron tomography. [DOI:10.1371/journal.pone.0043783]

Canonical examples

NCBITaxon:5741 Giardia intestinalis — Parasitic diplomonad model used for electron-tomographic mapping of the ventral-disc microtubule spiral. [DOI:10.1371/journal.pone.0043783]

Functions

ventral disc microtubule scaffold — The spiral microtubule array forms the Giardia ventral-disc scaffold and the base of dorsal microribbons.
- GO:0097593 Gene Ontology defines the ventral disc microtubule array as a spiral microtubule array whose microtubules form the base of the dorsal microribbons.
- DOI:10.1371/journal.pone.0043783 Schwartz et al. 2012 resolved the Giardia ventral-disc microtubule spiral and its associated microribbons by electron tomography.

Mechanism graphs

Tubulin microtubules form the Giardia ventral-disc spiral scaffold (ASSEMBLY)

In Giardia, alpha- and beta-tubulins polymerize into microtubules that form a left-handed spiral array within the ventral disc and serve as the base of dorsal microribbons.

Subject	Predicate	Object	Evidence
alpha- and beta-tubulins	polymerize into	ventral disc microtubule array	`GO:0005874` Gene Ontology defines microtubules as polymeric tubulin tubes. `DOI:10.1371/journal.pone.0043783` Schwartz et al. 2012 mapped the spiral organization of Giardia ventral-disc microtubules by electron tomography.
ventral disc microtubule array	forms base of	ventral disc dorsal microribbon	`GO:0097593` Gene Ontology states that ventral-disc microtubules form the base of dorsal microribbons.
ventral disc microtubule array	is part of	ventral disc	`GO:0097593` Gene Ontology models GO:0097593 as part of GO:0097597, the ventral disc.

Discussions

CURATION_TODO (OPEN): Resolve exact source-neutral grounding for the alpha- and beta-tubulins that build the Giardia ventral-disc microtubule array. This first ventral disc microtubule-array record keeps its tubulin component label-only because a broad tubulin domain or family accession may not exactly denote the alpha- and beta-tubulins that polymerize into Giardia ventral-disc microtubules.
CURATION_TODO (OPEN): Resolve exact component boundaries and source-neutral groundings for gMIP, gMAP, side-arm, paddle and microribbon-bridge densities on Giardia ventral-disc microtubules. Schwartz et al. 2012 resolved inner-wall, outer-wall, side-arm, paddle and microribbon-bridge densities associated with the ventral-disc microtubule wall, but this pass keeps them out of components until their protein identities, family boundaries and relations to dorsal-microribbon or crossbridge components are curated exactly.

Evidence

GO:0097593 Gene Ontology cellular-component term for the Giardia ventral-disc microtubule array.
DOI:10.1371/journal.pone.0043783 Schwartz, Heumann, Dawson and Hoenger 2012, 'A Detailed, Hierarchical Study of Giardia lamblia's Ventral Disc Reveals Novel Microtubule-Associated Protein Complexes', PLOS ONE.

Curation history

2026-09-15T14:30:27Z codex · CREATED_RECORD — Scaffolded by scripts/new_record.py
2026-09-15T14:31:37Z codex · EXPANDED_RECORD — Added GO ventral-disc microtubule-array synonyms, ventral-disc partonomy, a label-only tubulin component, Giardia intestinalis scope, a scaffold function, DOI evidence, a nonmechanistic scaffold graph, and a tubulin-grounding TODO.
2026-09-15T14:36:42Z codex · NORMALIZED_GO_LABELS — Collapsed the GO:0005874 graph node into a direct tubulin-to-array edge so graph node labels no longer pluralize the canonical GO microtubule label.
2026-09-15T14:47:15Z codex · REVIEW_FIX — Addressed PR #987 review issues #988 and #989 by replacing the location-specific tubulin component label with a source-neutral alpha/beta tubulin label and adding an explicit TODO for unresolved gMIP, gMAP, side-arm, paddle and bridge components.

Source: data/structures/cytoskeleton/ventral_disc_microtubule_array.yaml