mitotic spindle pole body

GO:0044732 · Cytoskeleton · Multiprotein complex · Proposed

The microtubule organizing center that forms as part of the mitotic cell cycle; functionally homologous to the animal cell centrosome. [GO:0044732]

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

Taxonomic distribution

NCBITaxon:4932 Saccharomyces cerevisiae — COMMON: Budding yeast mitotic spindle pole bodies are layered fungal microtubule-organizing centers that duplicate during mitotic cell-cycle entry. [DOI:10.1146/annurev.cellbio.20.022003.114106]

Canonical examples

NCBITaxon:4932 Saccharomyces cerevisiae — Reference fungal model in which mitotic SPB duplication and layered plaque topology have been reviewed. [DOI:10.1146/annurev.cellbio.20.022003.114106]

Functions

mitotic spindle microtubule organization — Mitotic spindle pole bodies organize budding-yeast nuclear and cytoplasmic microtubule nucleation during the mitotic cell cycle.
- GO:0044732 GO:0044732 defines the mitotic spindle pole body as the microtubule-organizing center formed as part of the mitotic cell cycle.
- DOI:10.1146/annurev.cellbio.20.022003.114106 Jaspersen and Winey 2004 reviewed budding-yeast SPB duplication and mitotic microtubule organization.

Mechanism graphs

Mitotic spindle pole bodies include mitotic half-bridge and intermediate-layer substructures (ASSEMBLY)

The mitotic spindle pole body is a cell-cycle-specific subtype of the fungal SPB and contains mitotic half-bridge and intermediate-layer substructures.

Subject	Predicate	Object	Evidence
mitotic spindle pole body	is subtype of	spindle pole body	`GO:0044732` GO:0044732 is a cellular-component child of the general spindle pole body term. `GO:0005816` GO:0005816 identifies the broader fungal spindle pole body.
half bridge of mitotic spindle pole body	is part of	mitotic spindle pole body	`GO:0061496` GO:0061496 is a part_of child of the mitotic spindle pole body term.
intermediate layer of mitotic spindle pole body	is part of	mitotic spindle pole body	`GO:0061498` GO:0061498 is a part_of child of the mitotic spindle pole body term.
half bridge of mitotic spindle pole body	templates assembly of	mitotic spindle pole body	`DOI:10.1146/annurev.cellbio.20.022003.114106` Jaspersen and Winey 2004 reviewed the half-bridge pathway for budding-yeast SPB duplication.

Discussions

INTERPRETATION (RESOLVED): Keep the mitotic spindle pole body narrower than the general fungal spindle pole body while preserving mitotic SPB substructures as child or part records. GO:0044732 denotes the mitotic SPB formed as part of the mitotic cell cycle. The broader GO:0005816 term covers the general fungal SPB, while GO:0061496 and GO:0061498 denote mitotic substructures that remain narrower than this parent.
CURATION_TODO (OPEN): Resolve exact source-neutral family groundings for mitotic SPB plaque, bridge, and gamma-tubulin-complex constituents. This first GO-backed mitotic SPB record captures the named cell-cycle-specific structure without guessing exact InterPro, Pfam, NCBIfam, or Complex Portal groundings for budding-yeast proteins and associated gamma-tubulin complexes.

Evidence

GO:0044732 Gene Ontology cellular-component term for the mitotic spindle pole body.
GO:0005816 Gene Ontology parent term for the general fungal spindle pole body.
GO:0061496 Gene Ontology cellular-component term for the half bridge of the mitotic spindle pole body.
GO:0061498 Gene Ontology cellular-component term for the intermediate layer of the mitotic spindle pole body.
DOI:10.1146/annurev.cellbio.20.022003.114106 Jaspersen and Winey 2004, The budding yeast spindle pole body: structure, duplication, and function, Annual Review of Cell and Developmental Biology.

Curation history

2026-09-29T14:06:46Z codex · CREATED_RECORD — Scaffolded by scripts/new_record.py
2026-09-29T14:07:34Z codex · EXPANDED_RECORD — Added GO-backed spindle-pole-body parentage, Saccharomyces scope, a mitotic microtubule-organization function, GO and literature evidence, a nonmechanistic mitotic SPB substructure graph, and boundary/component discussions.

Source: data/structures/cytoskeleton/mitotic_spindle_pole_body.yaml