germ tube septin ring

GO:0032172 · Cytoskeleton · Filament · Proposed

A tight ring-shaped structure that forms in the division plane within the germ tube of filamentous fungi at sites where a septum will form; composed of septins as well as septin-associated proteins. [GO:0032172]

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
septin proteins	Protein	part of	Reviewed label only (reviewed name; no accession asserted)			ESSENTIAL	Septin GTPases that assemble into the ring-shaped structure at future septation sites within filamentous fungal germ tubes. `GO:0032172` GO:0032172 defines the germ tube septin ring as composed of septins and septin-associated proteins. `GO:0005940` GO:0005940 defines the broader septin ring as a septin- and septin-associated-protein structure.

Mechanism graphs

Germ-tube septin-ring topology (ASSEMBLY)

Septin proteins form a ring-shaped structure at future septation sites within filamentous fungal germ tubes.

Subject	Predicate	Object	Evidence
septin proteins	assemble into	germ tube septin ring	`GO:0032172` GO:0032172 defines the germ tube septin ring as composed of septins and septin-associated proteins.
germ tube septin ring	forms at	germ-tube septation site	`GO:0032172` GO:0032172 places the germ tube septin ring within the germ tube of filamentous fungi at future septation sites.

Discussions

INTERPRETATION (RESOLVED): Keep the germ tube septin ring distinct from other localized fungal septin-ring states. GO:0032172 denotes the septin ring within a filamentous fungal germ tube at future septation sites. GO:0032168 covers the analogous ring within hyphae of filamentous fungi, GO:0032170 covers the ring at the mother-cell/pseudohyphal-projection junction, and GO:0005940 denotes the broader septin ring class. This record models only the germ-tube subtype.
CURATION_TODO (OPEN): Resolve exact source-neutral family groundings and boundary status for germ-tube septin-ring septins and septin-associated proteins. The first germ tube septin-ring record keeps only the reviewed-label-only septin protein cohort rather than guessing fungal-paralog family groundings or adding septin-associated proteins before their exact constituent boundary has been reviewed.

Evidence

GO:0032172 Gene Ontology cellular-component term for the germ tube septin ring.
GO:0005940 Gene Ontology cellular-component parent term for the septin ring.

Curation history

2026-09-29T01:46:20Z codex · CREATED_RECORD — Scaffolded by scripts/new_record.py
2026-09-29T01:47:17Z codex · EXPANDED_RECORD — Added septin-ring parentage, a reviewed-label-only septin constituent, GO evidence, a nonmechanistic germ-tube-ring topology graph, and boundary and component-grounding discussions.
2026-09-29T02:06:48Z codex · ADDRESSED_REVIEW — Resolved #1755 by tightening the GO:0032172 boundary discussion against hyphal and pseudohyphal septin-ring sibling records.

Source: data/structures/cytoskeleton/germ_tube_septin_ring.yaml