title: Mps1 phosphorylation sites regulate the function of centrin 2 in centriole assembly.
abstract: The nondegradable Mps1(Δ12/13) protein drives centriole overproduction, suggesting that Mps1 phosphorylates a subset of centrosomal proteins to drive the assembly of new centrioles. Here we identify three Mps1 phosphorylation sites within the centriolar protein Centrin 2 (Cetn2). Although centrioles can be assembled in the absence of Cetn2, centriole assembly is attenuated in the absence of Cetn2. While wild-type Cetn2 can compensate for this attenuation, a nonphosphorylatable version cannot. In addition, overexpressing Cetn2 causes Mps1-dependent centriole overproduction that requires each of the three Mps1 phosphorylation sites within Cetn2 and is greatly exacerbated by mimicking phosphorylation at any of these sites. Wild-type Cetn2 generates excess foci that are competent as mitotic spindle poles in HsSas-6-depleted cells, suggesting that Cetn2 can organize a subset of centriolar proteins independently of cartwheels. However, centriole overproduction caused by a phosphomimetic Cetn2 mutant requires HsSas-6, suggesting that Cetn2 phosphorylation stimulates the canonical centriole assembly pathway. Moreover, in the absence of Cetn2, Mps1(Δ12/13) cannot drive the production of mature centrioles capable of recruiting γ-Tubulin, and a nonphosphorylatable Cetn2 mutant cannot compensate for this defect and exacerbates Cetn2 depletion. Together, our data suggest that Mps1-dependent phosphorylation of Cetn2 stimulates the canonical centriole assembly pathway.
authors.affiliation: Department of Molecular Genetics, Ohio State University, Columbus OH 43210-1292, USA.
authors.forename: Ching-Hui
authors.initials: CH
authors.lastname: Yang
authors.forename: Christopher
authors.initials: C
authors.lastname: Kasbek
authors.forename: Shubhra
authors.initials: S
authors.lastname: Majumder
authors.forename: Adlina Mohd
authors.initials: AM
authors.lastname: Yusof
authors.forename: Harold A
authors.initials: HA
authors.lastname: Fisk
mesh_terms: D000595:Amino Acid Sequence; D002135:Calcium-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D002460:Cell Line; D002502:Centrioles / Q000378:metabolism* / Q000502:physiology / Q000648:ultrastructure; D018385:Centrosome / Q000378:metabolism / Q000502:physiology; D006801:Humans; D008969:Molecular Sequence Data; D009154:Mutation; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D011505:Protein-Tyrosine Kinases; D034741:RNA, Small Interfering; D008941:Spindle Apparatus / Q000378:metabolism / Q000502:physiology; D014404:Tubulin / Q000378:metabolism
chemical_list: C472752:CETN2 protein, human; D002135:Calcium-Binding Proteins; D018797:Cell Cycle Proteins; D034741:RNA, Small Interfering; D014404:Tubulin; D011505:Protein-Tyrosine Kinases; D017346:Protein Serine-Threonine Kinases; C075840:TTK protein, human