Interaction of CK1δ with γTuSC ensures proper microtubule assembly and spindle positioning

Yutian Peng, Michelle Moritz, Xuemei Han, Thomas H. Giddings, Andrew Lyon, Justin Kollman, Mark Winey, John Yates, David A. Agard, David G. Drubin, Georjana Barnes

Research output: Contribution to journalArticlepeer-review

17 Scopus citations


Casein kinase 1δ (CK1δ) family members associate with microtubule-organizing centers (MTOCs) from yeast to humans, but their mitotic roles and targets have yet to be identified. We show here that budding yeast CK1δ, Hrr25, is a γ-tubulin small complex (γTuSC) binding factor. Moreover, Hrr25's association with γTuSC depends on its kinase activity and its noncatalytic central domain. Loss of Hrr25 kinase activity resulted in assembly of unusually long cytoplasmic microtubules and defects in spindle positioning, consistent with roles in regulation of γTuSC-mediated microtubule nucleation and the Kar9 spindle-positioning pathway, respectively. Hrr25 directly phosphorylated γTuSC proteins in vivo and in vitro, and this phosphorylation promoted γTuSC integrity and activity. Because CK1δ and γTuSC are highly conserved and present at MTOCs in diverse eukaryotes, similar regulatory mechanisms are expected to apply generally in eukaryotes.

Original languageEnglish (US)
Pages (from-to)2505-2518
Number of pages14
JournalMolecular Biology of the Cell
Issue number13
StatePublished - Jan 1 2015
Externally publishedYes

ASJC Scopus subject areas

  • Molecular Biology
  • Cell Biology


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