spindle pole body

GO:0005816 · Cytoskeleton · Multiprotein complex · Proposed

The microtubule-organizing center in fungi, functionally homologous to the animal centrosome. [GO:0005816]

Synonyms: SPB

Components

Component	Type	Part of / acts on	Grounding	Genes	Stoichiometry	Essential	Role
spindle pole body core	Protein complex	part of	Reviewed label only (reviewed name; no accession asserted)				Native multilayered scaffold subcomplex at the center of the budding-yeast SPB that organizes cytoplasmic and nuclear microtubule nucleation sites. `DOI:10.1146/annurev.cellbio.20.022003.114106` Jaspersen and Winey 2004 reviewed the layered Saccharomyces cerevisiae SPB and its core plaque components. `DOI:10.1091/mbc.E17-06-0397` Viswanath et al. 2017 determined an integrative molecular architecture for the budding-yeast SPB core.
gamma-tubulin complexes	Protein complex	part of	Reviewed label only (reviewed name; no accession asserted)				Microtubule-nucleating complexes associated with SPB inner and outer plaques. `DOI:10.1146/annurev.cellbio.20.022003.114106` Jaspersen and Winey 2004 reviewed gamma-tubulin complex placement at budding-yeast SPB plaques.

NCBITaxon:4932 Saccharomyces cerevisiae — COMMON: The spindle pole body is directly evidenced in budding yeast; no broader fungal distribution is asserted in this first record. [DOI:10.1146/annurev.cellbio.20.022003.114106]

NCBITaxon:4932 Saccharomyces cerevisiae — Budding-yeast reference system in which SPB structure, duplication and core molecular architecture have been mapped. [DOI:10.1146/annurev.cellbio.20.022003.114106]

microtubule organization — The SPB nucleates and organizes nuclear and cytoplasmic microtubules in budding yeast.
- DOI:10.1146/annurev.cellbio.20.022003.114106 Jaspersen and Winey 2004 reviewed the SPB as the budding-yeast microtubule organizing center.
bipolar spindle assembly — SPB duplication and separation generate the two organizing centers that build a bipolar mitotic spindle.
- DOI:10.1146/annurev.cellbio.20.022003.114106 Jaspersen and Winey 2004 reviewed SPB duplication and mitotic-spindle assembly.

A new SPB assembles next to the old SPB at the half-bridge during the budding-yeast duplication pathway.

Subject	Predicate	Object	Evidence
old spindle pole body	templates assembly of	new spindle pole body	`DOI:10.1146/annurev.cellbio.20.022003.114106` Jaspersen and Winey 2004 reviewed the half-bridge-associated pathway for SPB duplication.

CURATION_TODO (OPEN): Resolve exact groundings for SPB plaques, bridge substructures and gamma-tubulin complexes. The first record captures SPB structure at component-class resolution. Follow-up curation should split the central, outer and inner plaque and half-bridge subassemblies only where exact identifiers or reviewed label-only boundaries can be justified from primary structural work.

GO:0005816 Gene Ontology cellular-component term for spindle pole body, with SPB as an exact synonym.
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.
DOI:10.1091/mbc.E17-06-0397 Viswanath et al. 2017, The molecular architecture of the yeast spindle pole body core determined by Bayesian integrative modeling, Molecular Biology of the Cell.

2026-09-10T14:20:45Z claude · CREATED_RECORD — Scaffolded by scripts/new_record.py
2026-09-10T14:22:32Z claude · EXPANDED_RECORD — Added the SPB synonym, reviewed-label-only core and gamma-tubulin-complex components, Saccharomyces cerevisiae scope, microtubule-organization and bipolar-spindle-assembly functions, record evidence, a nonmechanistic SPB duplication graph, and a subassembly grounding TODO.
2026-09-10T14:30:53Z claude · FIX_ID_LABEL_FINDINGS — Removed GO:0005816 graph-node groundings from old_spb and new_spb because their labels are local causal-graph roles rather than the canonical spindle pole body label.
2026-09-10T14:40:59Z claude · ADDRESS_REVIEW — Addressed #381 and #382 by remodeling the SPB core row as a reviewed-label-only protein complex and narrowing the causal graph to an ASSEMBLY-scoped SPB duplication graph.