title: Phosphorylation of the yeast γ-tubulin Tub4 regulates microtubule function.
abstract: The yeast γ-tubulin Tub4 is assembled with Spc97 and Spc98 into the small Tub4 complex. The Tub4 complex binds via the receptor proteins Spc72 and Spc110 to the spindle pole body (SPB), the functional equivalent of the mammalian centrosome, where the Tub4 complex organizes cytoplasmic and nuclear microtubules. Little is known about the regulation of the Tub4 complex. Here, we isolated the Tub4 complex with the bound receptors from yeast cells. Analysis of the purified Tub4 complex by mass spectrometry identified more than 50 phosphorylation sites in Spc72, Spc97, Spc98, Spc110 and Tub4. To examine the functional relevance of the phosphorylation sites, phospho-mimicking and non-phosphorylatable mutations in Tub4, Spc97 and Spc98 were analyzed. Three phosphorylation sites in Tub4 were found to be critical for Tub4 stability and microtubule organization. One of the sites is highly conserved in γ-tubulins from yeast to human.
authors.affiliation: Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Allianz, Heidelberg, Germany.
authors.forename: Tien-chen
authors.initials: TC
authors.lastname: Lin
authors.forename: Linda
authors.initials: L
authors.lastname: Gombos
authors.forename: Annett
authors.initials: A
authors.lastname: Neuner
authors.forename: Dominik
authors.initials: D
authors.lastname: Sebastian
authors.forename: Jesper V
authors.initials: JV
authors.lastname: Olsen
authors.forename: Ajla
authors.initials: A
authors.lastname: Hrle
authors.forename: Christian
authors.initials: C
authors.lastname: Benda
authors.forename: Elmar
authors.initials: E
authors.lastname: Schiebel
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000378:metabolism; D002148:Calmodulin-Binding Proteins; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D003598:Cytoskeletal Proteins / Q000378:metabolism; D006801:Humans; D007210:Indoleacetic Acids / Q000494:pharmacology; D064246:Mad2 Proteins; D050296:Microbial Viability / Q000187:drug effects; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D008870:Microtubules / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure*; D008969:Molecular Sequence Data; D050505:Mutant Proteins / Q000378:metabolism; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D010641:Phenotype; D010766:Phosphorylation / Q000187:drug effects; D011485:Protein Binding / Q000187:drug effects; D021122:Protein Subunits / Q000378:metabolism; D021381:Protein Transport / Q000187:drug effects; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008941:Spindle Apparatus / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D014404:Tubulin / Q000737:chemistry / Q000378:metabolism*
chemical_list: D000596:Amino Acids; D002148:Calmodulin-Binding Proteins; D018797:Cell Cycle Proteins; D003598:Cytoskeletal Proteins; D007210:Indoleacetic Acids; C577695:MAD2 protein, S cerevisiae; D064246:Mad2 Proteins; D008869:Microtubule-Associated Proteins; D050505:Mutant Proteins; D009687:Nuclear Proteins; D021122:Protein Subunits; C073277:SPC110 protein, S cerevisiae; C418484:SPC72 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; C100764:TUB4 protein, S cerevisiae; D014404:Tubulin