septin band

GO:0032158 · Cytoskeleton · Filament · Proposed

A diffuse ring composed of a series of septin bars that run parallel to the long axis of the cell. This type of septin structure has been observed in a number of locations associated with polarized growth and/or deposition of new membrane, but not with cytokinesis, such as at the shmoo (mating projection) neck, at the junction between the mother cell and the germ tube (hypha) of a fungal cell growing filamentously. [GO:0032158]

Part of: GO:0032156 — septin cytoskeleton (no local record)

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 form the diffuse bar series running parallel to the long axis of the cell in a septin band. `GO:0032158` GO:0032158 defines a septin band as a diffuse ring composed of a series of septin bars.

Mechanism graphs

Septin-band topology (ASSEMBLY)

Septin proteins form diffuse parallel bars in septin bands used at noncytokinetic polarized-growth or new-membrane-deposition sites.

Subject	Predicate	Object	Evidence
septin proteins	form	septin band	`GO:0032158` GO:0032158 defines the septin band as a diffuse ring composed of a series of septin bars.
septin band	is part of	septin cytoskeleton	`GO:0032156` — septin cytoskeleton OLS reports GO:0032158 as part_of GO:0032156.
septin band	is localized at	mating projection neck	`GO:0032162` GO:0032162 is a direct septin-band child term for the mating projection septin band.
septin band	is localized at	mother cell-germ tube junction	`GO:0032163` GO:0032163 is a direct septin-band child term for the hyphal septin band.

Discussions

INTERPRETATION (RESOLVED): Keep the generic septin band distinct from localized mating-projection and hyphal septin-band subtypes and from cytokinetic septin rings. GO:0032158 denotes the broader diffuse, noncytokinetic septin band, whereas GO:0032162 and GO:0032163 narrow that morphology to the mating-projection neck and the mother cell-germ tube junction. GO:0005940 separately denotes cytokinetic septin rings.
CURATION_TODO (OPEN): Resolve an exact source-neutral grounding for septin-band septin proteins. The initial generic septin-band record uses a reviewed-label-only septin protein cohort rather than guessing InterPro, Pfam, or NCBIfam accessions that may not exactly delimit all septins that form diffuse band-shaped assemblies.

Evidence

GO:0032158 Gene Ontology cellular-component term for the septin band.
GO:0110165 OLS reports GO:0110165 cellular anatomical structure as a direct GO:0032158 parent.
GO:0032156 — septin cytoskeleton OLS reports a direct GO:0032158 part_of relation to the septin cytoskeleton.
GO:0032162 OLS reports the mating projection septin band as a direct GO:0032158 child term.
GO:0032163 OLS reports the hyphal septin band as a direct GO:0032158 child term.

Curation history

2026-09-30T14:21:34Z codex · CREATED_RECORD — Scaffolded by scripts/new_record.py
2026-09-30T14:22:32Z codex · EXPANDED_RECORD — Added cellular-anatomical-structure parentage, septin-cytoskeleton parthood, a reviewed-label-only septin constituent, GO-backed band topology, and boundary and component-grounding discussions.
2026-10-11T13:43:17Z codex · ADDRESS_SAVED_REVIEW — Addressed #2216: Corrected the inherited GO definition typo polarized grown to polarized growth without changing scientific meaning or source.

Source: data/structures/cytoskeleton/septin_band.yaml