axonemal central bridge

GO:1990717 · Cytoskeleton · Multiprotein complex · Proposed

A bridge network that connects the C1 and C2 singlet microtubules of the 9+2 axonemal central apparatus. [GO:1990717]

Part of: axonemal central apparatus (GO:1990716)

Components

Component	Type	Part of / acts on	Grounding	Genes	Stoichiometry	Essential	Role
axonemal central-bridge proteins	Protein	part of	Reviewed label only (reviewed name; no accession asserted)			UNKNOWN	Protein constituents of the bridge network that links C1 and C2 microtubules in the central pair complex. `GO:1990717` GO identifies the axonemal central bridge as the structure connecting the central-pair single microtubules. `DOI:10.1002/cm.21094` Carbajal-Gonzalez et al. 2013 resolved a complex Chlamydomonas bridge density network linking the C1 and C2 central-pair microtubules.

NCBITaxon:3055 Chlamydomonas reinhardtii — COMMON: Chlamydomonas flagellar central pair complexes contain a 16 nm-periodic bridge network between the C1 and C2 microtubules. [DOI:10.1002/cm.21094]

NCBITaxon:3055 Chlamydomonas reinhardtii — Green-algal model whose central pair complex bridge was resolved by cryoelectron tomography and subtomogram averaging. [DOI:10.1002/cm.21094]

C1-C2 microtubule linkage — The axonemal central bridge connects the C1 and C2 singlet microtubules within the central pair complex.
- GO:1990717 GO defines the axonemal central bridge as the bridge structures connecting the central pair of single microtubules.
- DOI:10.1002/cm.21094 Carbajal-Gonzalez et al. 2013 showed that the Chlamydomonas and Strongylocentrotus bridge is a complex network that links C1 and C2.

Axonemal central-bridge proteins form the bridge network that connects the C1 and C2 microtubules of the Chlamydomonas central pair complex.

Subject	Predicate	Object	Evidence
axonemal central-bridge proteins	form	axonemal central bridge	`DOI:10.1002/cm.21094` Carbajal-Gonzalez et al. 2013 resolved the Chlamydomonas central bridge by cryo-ET and noted that PF20 was the only protein then localized unambiguously to the bridge.
axonemal central bridge	connects to	C1 axonemal microtubule	`GO:1990717` GO defines the axonemal central bridge as connecting the central pair of single microtubules.
axonemal central bridge	connects to	C2 axonemal microtubule	`GO:1990717` GO defines the axonemal central bridge as two bridges linking the two central-pair microtubules.
axonemal central bridge	is part of	axonemal central apparatus	`GO:1990717` GO places the axonemal central bridge within the axonemal central apparatus.

CURATION_TODO (OPEN): Resolve exact source-neutral groundings for PF20, PF16 and other axonemal central-bridge constituent families, bridge membership and copy numbers. Carbajal-Gonzalez et al. 2013 described the bridge density network but also noted that central-bridge protein composition was limited and only PF20 had then been localized unambiguously to the bridge.

GO:1990717 Gene Ontology cellular-component term for the axonemal central bridge.
GO:1990716 Gene Ontology places the axonemal central bridge within the axonemal central apparatus.
DOI:10.1002/cm.21094 Carbajal-Gonzalez et al. 2013, 'Conserved structural motifs in the central pair complex of eukaryotic flagella', Cytoskeleton.

2026-09-23T14:29:12Z codex · CREATED_RECORD — Scaffolded by scripts/new_record.py
2026-09-23T14:30:12Z codex · EXPANDED_RECORD — Added central-apparatus parthood, a reviewed-label-only central-bridge protein component, Chlamydomonas scope, a C1-C2 linkage function, GO and DOI evidence, a nonmechanistic bridge linkage graph, and a central-bridge composition TODO.
2026-09-23T14:49:00Z codex · ADDRESSED_REVIEW — Resolved PR #1402 review issue #1403 by singularizing the central-bridge graph title to match GO:1990717.