title: Mzt1/Tam4, a fission yeast MOZART1 homologue, is an essential component of the γ-tubulin complex and directly interacts with GCP3(Alp6).
abstract: In humans, MOZART1 plays an essential role in mitotic spindle formation as a component of the γ-tubulin ring complex. We report that the fission yeast homologue of MOZART1, Mzt1/Tam4, is located at microtubule-organizing centers (MTOCs) and coimmunoprecipitates with γ-tubulin Gtb1 from cell extracts. We show that mzt1/tam4 is an essential gene in fission yeast, encoding a 64-amino acid peptide, depletion of which leads to aberrant microtubule structure, including malformed mitotic spindles and impaired interphase microtubule array. Mzt1/Tam4 depletion also causes cytokinesis defects, suggesting a role of the γ-tubulin complex in the regulation of cytokinesis. Yeast two-hybrid analysis shows that Mzt1/Tam4 forms a complex with Alp6, a fission yeast homologue of γ-tubulin complex protein 3 (GCP3). Biophysical methods demonstrate that there is a direct interaction between recombinant Mzt1/Tam4 and the N-terminal region of GCP3(Alp6). Together our results suggest that Mzt1/Tam4 contributes to the MTOC function through regulation of GCP3(Alp6).
authors.affiliation: Department of Biochemistry, University of Leicester, Leicester LE1 9HN, United Kingdom Paterson Institute for Cancer Research, University of Manchester, Manchester M20 4BX, United Kingdom.
authors.forename: Deepsharan K
authors.initials: DK
authors.lastname: Dhani
authors.forename: Benjamin T
authors.initials: BT
authors.lastname: Goult
authors.forename: Gifty M
authors.initials: GM
authors.lastname: George
authors.forename: Daniel T
authors.initials: DT
authors.lastname: Rogerson
authors.forename: Danny A
authors.initials: DA
authors.lastname: Bitton
authors.forename: Crispin J
authors.initials: CJ
authors.lastname: Miller
authors.forename: John W R
authors.initials: JW
authors.lastname: Schwabe
authors.forename: Kayoko
authors.initials: K
authors.lastname: Tanaka
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites / Q000235:genetics; D015153:Blotting, Western; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D008856:Microscopy, Fluorescence; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism*; D022101:Microtubule-Organizing Center / Q000378:metabolism; D008969:Molecular Sequence Data; D011485:Protein Binding; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism; D012568:Schizosaccharomyces / Q000235:genetics / Q000378:metabolism*; D029702:Schizosaccharomyces pombe Proteins / Q000235:genetics / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D014404:Tubulin / Q000235:genetics / Q000378:metabolism*; D020798:Two-Hybrid System Techniques
chemical_list: C512341:Alp6 protein, S pombe; C000589193:MZT1 protein, human; D008869:Microtubule-Associated Proteins; C000589192:Mzt1 protein, S pombe; D021122:Protein Subunits; D029702:Schizosaccharomyces pombe Proteins; D014404:Tubulin; D049452:Green Fluorescent Proteins