spindle pole body satellite

cellstructuremech:spindle_pole_body_satellite · Cytoskeleton · Multiprotein complex · Proposed

A transient cytoplasmic precursor of the daughter spindle pole body that forms at the distal tip of the half bridge during spindle pole body duplication in budding yeast. [DOI:10.1146/annurev.cellbio.20.022003.114106]

Synonyms: SPB satellite

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

Taxonomic distribution

NCBITaxon:4932 Saccharomyces cerevisiae — COMMON: Budding yeast is the characterized model in which the SPB satellite forms at the distal end of the half bridge as an early daughter-SPB assembly intermediate. [DOI:10.1083/jcb.145.4.809]

Canonical examples

NCBITaxon:4932 Saccharomyces cerevisiae — Budding-yeast reference system for the half-bridge-associated SPB satellite precursor that seeds daughter spindle pole body assembly. [DOI:10.1083/jcb.145.4.809]

Functions

daughter spindle pole body precursor — The SPB satellite is an early cytoplasmic intermediate that nucleates assembly of the daughter spindle pole body next to the existing SPB.
- DOI:10.1146/annurev.cellbio.20.022003.114106 Jaspersen and Winey 2004 reviewed budding-yeast SPB duplication as a pathway that starts with satellite formation on the half bridge.

Mechanism graphs

SPB satellite precursor in daughter spindle pole body assembly (ASSEMBLY)

During budding-yeast SPB duplication, a satellite forms at the half bridge and seeds assembly of the daughter spindle pole body.

Subject	Predicate	Object	Evidence
half bridge of spindle pole body	templates assembly of	spindle pole body satellite	`DOI:10.1146/annurev.cellbio.20.022003.114106` Jaspersen and Winey 2004 reviewed the satellite as a half-bridge-associated intermediate in budding-yeast SPB duplication.
spindle pole body satellite	is precursor of	daughter spindle pole body	`DOI:10.1146/annurev.cellbio.20.022003.114106` Jaspersen and Winey 2004 reviewed the budding-yeast SPB satellite as the initial visible intermediate that forms at the half bridge during daughter SPB assembly. `DOI:10.1083/jcb.145.4.809` Adams and Kilmartin 1999 localized core budding-yeast SPB components during the satellite and daughter-plaque stages of SPB duplication.

Discussions

INTERPRETATION (RESOLVED): Keep the spindle pole body satellite distinct from the mature spindle pole body and from the half bridge. The satellite is modeled as a transient protein-containing complex that seeds daughter SPB assembly at the half bridge, not as an exact synonym of the mature GO:0005816 spindle pole body or the GO:0005825 half bridge.
CURATION_TODO (OPEN): Resolve exact source-neutral family groundings for SPB satellite constituents. The first SPB satellite record captures the transient precursor without guessing exact InterPro, Pfam, NCBIfam, or Complex Portal groundings for budding-yeast satellite constituents.

Evidence

GO:0032991 Gene Ontology cellular-component term for protein-containing complex, used as the broader parent because GO does not provide an exact SPB satellite term.
GO:0005825 Gene Ontology cellular-component term for the half bridge of the spindle pole body, the SPB substructure where satellite assembly initiates.
GO:0005816 Gene Ontology cellular-component term for the spindle pole body, the mature structure produced by the budding-yeast satellite precursor.
DOI:10.1083/jcb.145.4.809 Adams and Kilmartin 1999, Localization of core spindle pole body components during spindle pole body duplication in Saccharomyces cerevisiae, Journal of Cell Biology.
DOI:10.1534/genetics.111.128710 Winey and Bloom 2012, Mitotic spindle form and function, Genetics.
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

2026-09-29T10:41:18Z codex · CREATED_RECORD — Scaffolded by scripts/new_record.py
2026-09-29T10:42:36Z codex · EXPANDED_RECORD — Added SPB satellite synonymy, protein-containing-complex parentage, Saccharomyces scope, a daughter-SPB precursor function, GO and literature evidence, a nonmechanistic satellite assembly graph, and boundary/component discussions.
2026-09-29T10:54:18Z codex · FIX_LOCAL_QC — Resolved local corpus-integrity failure by anchoring the SPB satellite boundary discussion to causal_graphs#spb_satellite_precursor_assembly.
2026-09-29T11:09:15Z codex · ADDRESSED_REVIEW — Resolved PR #1778 review issue #1779 by tightening the SPB satellite precursor edge evidence to mention the satellite and daughter-SPB assembly stages directly.

Source: data/structures/cytoskeleton/spindle_pole_body_satellite.yaml