title: The Bud14p-Glc7p complex functions as a cortical regulator of dynein in budding yeast.
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.
authors.affiliation: Swiss Federal Institute of Technology Zürich (ETH), Institute of Biochemistry, Zürich, Switzerland.
authors.forename: Michèle
authors.initials: M
authors.lastname: Knaus
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Cameroni
authors.forename: Ivo
authors.initials: I
authors.lastname: Pedruzzi
authors.forename: Kelly
authors.initials: K
authors.lastname: Tatchell
authors.forename: Claudio
authors.initials: C
authors.lastname: De Virgilio
authors.forename: Matthias
authors.initials: M
authors.lastname: Peter
mesh_terms: D008841:Actin Cytoskeleton / Q000378:metabolism; D048868:Adaptor Proteins, Signal Transducing; D020816:Amino Acid Motifs; D002352:Carrier Proteins / Q000378:metabolism; D017124:Conserved Sequence; D048749:Cytokinesis; D000072159:Dynactin Complex; D004398:Dyneins / Q000378:metabolism*; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D008870:Microtubules / Q000378:metabolism; D008938:Mitosis; D009154:Mutation; D010749:Phosphoprotein Phosphatases / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D054645:Protein Phosphatase 1; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D008941:Spindle Apparatus
chemical_list: D048868:Adaptor Proteins, Signal Transducing; C474555:Bud14 protein, S cerevisiae; D002352:Carrier Proteins; D000072159:Dynactin Complex; C489835:KEL1 protein, S cerevisiae; C489836:KEL2 protein, S cerevisiae; D008869:Microtubule-Associated Proteins; D029701:Saccharomyces cerevisiae Proteins; C092048:GLC7 protein, S cerevisiae; D010749:Phosphoprotein Phosphatases; D054645:Protein Phosphatase 1; D004398:Dyneins