The Bud14p-Glc7p complex functions as a cortical regulator of dynein in budding yeast

EMBO J. 2005 Sep 7;24(17):3000-11. doi: 10.1038/sj.emboj.7600783. Epub 2005 Aug 18.

Abstract

Regulated interactions between microtubules (MTs) and the cell cortex control MT dynamics and position the mitotic spindle. In eukaryotic cells, the adenomatous polyposis coli/Kar9p and dynein/dynactin pathways are involved in guiding MT plus ends and MT sliding along the cortex, respectively. Here we identify Bud14p as a novel cortical activator of the dynein/dynactin complex in budding yeast. Bud14p accumulates at sites of polarized growth and the mother-bud neck during cytokinesis. The localization to bud and shmoo tips requires an intact actin cytoskeleton and the kelch-domain-containing proteins Kel1p and Kel2p. While cells lacking Bud14p function fail to stabilize the pre-anaphase spindle at the mother-bud neck, overexpression of Bud14p is toxic and leads to elongated astral MTs and increased dynein-dependent sliding along the cell cortex. Bud14p physically interacts with the type-I phosphatase Glc7p, and localizes Glc7p to the bud cortex. Importantly, the formation of Bud14p-Glc7p complexes is necessary to regulate MT dynamics at the cortex. Taken together, our results suggest that Bud14p functions as a regulatory subunit of the Glc7p type-I phosphatase to stabilize MT interactions specifically at sites of polarized growth.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actin Cytoskeleton / metabolism
  • Adaptor Proteins, Signal Transducing
  • Amino Acid Motifs
  • Carrier Proteins / metabolism
  • Conserved Sequence
  • Cytokinesis
  • Dynactin Complex
  • Dyneins / metabolism*
  • Microtubule-Associated Proteins / metabolism
  • Microtubules / metabolism
  • Mitosis
  • Mutation
  • Phosphoprotein Phosphatases / genetics
  • Phosphoprotein Phosphatases / metabolism*
  • Protein Binding
  • Protein Phosphatase 1
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae / metabolism*
  • Saccharomyces cerevisiae Proteins / genetics
  • Saccharomyces cerevisiae Proteins / metabolism*
  • Spindle Apparatus

Substances

  • Adaptor Proteins, Signal Transducing
  • Bud14 protein, S cerevisiae
  • Carrier Proteins
  • Dynactin Complex
  • KEL1 protein, S cerevisiae
  • KEL2 protein, S cerevisiae
  • Microtubule-Associated Proteins
  • Saccharomyces cerevisiae Proteins
  • GLC7 protein, S cerevisiae
  • Phosphoprotein Phosphatases
  • Protein Phosphatase 1
  • Dyneins