split septin rings

GO:0032176 · Cytoskeleton · Filament · Proposed

A pair of rings that flank the site of cell division, formed by splitting of the septin ring (or collar) prior to cytokinesis; this double ring structure is thought to trap proteins needed for cytokinesis or the formation of the new membrane or cell wall between the two septin rings. Split septin rings are known to occur in budding yeast cells and probably occur in other cell types as well. [GO:0032176]

Part of: GO:0005856 — 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 remain in the pair of rings after a septin ring or collar splits before cytokinesis. `GO:0032176` GO:0032176 defines split septin rings as a pair of rings formed by splitting of a septin ring or collar.

Functions

cytokinetic compartment boundary — Split septin rings flank the cell-division site and are thought to trap proteins needed for cytokinesis or for formation of the new membrane or cell wall between the two rings.
- GO:0032176 GO:0032176 describes the double ring structure as thought to trap cytokinesis, new-membrane, or new-cell-wall proteins.

Mechanism graphs

Split septin-rings topology (ASSEMBLY)

A septin ring or collar splits into a pair of septin rings that flank the site of cell division before cytokinesis.

Subject	Predicate	Object	Evidence
septin proteins	assemble into	split septin rings	`GO:0032176` GO:0032176 defines split septin rings as a pair of rings formed from a septin ring or collar.
septin ring or collar	splits into	split septin rings	`GO:0032176` GO:0032176 defines split septin rings as a double-ring structure produced when the septin ring or collar splits before cytokinesis.
split septin rings	flank	cell division site	`GO:0032176` GO:0032176 defines the split septin rings as a pair of rings that flank the site of cell division.

Discussions

INTERPRETATION (RESOLVED): Keep the generic split septin rings distinct from localized bud-neck split septin rings and from the precursor septin ring or collar. GO:0032176 denotes the broader pair of rings that forms when a septin ring or septin collar splits before cytokinesis. GO:0032177 narrows that state to the cellular bud neck, GO:0005940 denotes an unsplit septin ring, and GO:0032173 denotes an unsplit septin collar.
CURATION_TODO (OPEN): Resolve an exact source-neutral grounding for split-septin-rings septin proteins. The initial split septin rings 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 remain in split-ring pairs.

Evidence

GO:0032176 Gene Ontology cellular-component term for split septin rings.
GO:0032156 — septin cytoskeleton OLS reports GO:0032156 septin cytoskeleton as the direct GO:0032176 parent.
GO:0005856 — cytoskeleton OLS reports a direct GO:0032176 part_of relation to the cytoskeleton.
GO:0032177 OLS reports GO:0032177 cellular bud neck split septin rings as the direct GO:0032176 child.

Curation history

2026-09-30T16:36:00Z codex · CREATED_RECORD — Scaffolded by scripts/new_record.py
2026-09-30T16:37:18Z codex · EXPANDED_RECORD — Added septin-cytoskeleton parentage, cytoskeleton parthood, a reviewed-label-only septin constituent, a GO-backed cytokinetic compartment function, a nonmechanistic split-ring topology graph, and boundary and component-grounding discussions.
2026-09-30T17:09:36Z codex · ADDRESSED_REVIEW — Resolved #1834 in PR #1833 by grounding the split_septin_rings_topology cell_division_site node to GO:0032153.

Source: data/structures/cytoskeleton/split_septin_rings.yaml