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Higher-order oligomerization of Spc110p drives ?-tubulin ring complex assembly.

ABSTRACT: The microtubule (MT) cytoskeleton plays important roles in many cellular processes. In vivo, MT nucleation is controlled by the ?-tubulin ring complex (?TuRC), a 2.1-MDa complex composed of ?-tubulin small complex (?TuSC) subunits. The mechanisms underlying the assembly of ?TuRC are largely unknown. In yeast, the conserved protein Spc110p both stimulates the assembly of the ?TuRC and anchors the ?TuRC to the spindle pole body. Using a quantitative in vitro FRET assay, we show that ?TuRC assembly is critically dependent on the oligomerization state of Spc110p, with higher-order oligomers dramatically enhancing the stability of assembled ?TuRCs. Our in vitro findings were confirmed with a novel in vivo ?TuSC recruitment assay. We conclude that precise spatial control over MT nucleation is achieved by coupling localization and higher-order oligomerization of the receptor for ?TuRC.

SUBMITTER: Lyon AS

PROVIDER: S-EPMC4945142 | biostudies-literature | 2016 Jul

REPOSITORIES: biostudies-literature

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Higher-order oligomerization of Spc110p drives γ-tubulin ring complex assembly.

Lyon Andrew S AS Morin Geneviève G Moritz Michelle M Yabut King Clyde B KC Vojnar Tamira T Zelter Alex A Muller Eric E Davis Trisha N TN Agard David A DA

Molecular biology of the cell 20160525 14

The microtubule (MT) cytoskeleton plays important roles in many cellular processes. In vivo, MT nucleation is controlled by the γ-tubulin ring complex (γTuRC), a 2.1-MDa complex composed of γ-tubulin small complex (γTuSC) subunits. The mechanisms underlying the assembly of γTuRC are largely unknown. In yeast, the conserved protein Spc110p both stimulates the assembly of the γTuRC and anchors the γTuRC to the spindle pole body. Using a quantitative in vitro FRET assay, we show that γTuRC assembly ...[more]

PMID: 27226487

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