title: Consorting kinases, end of destruction and birth of a spindle.
abstract: Centrosomes (spindle pole body in yeast) constitute the two poles of the bipolar mitotic spindle and play a prominent role in the segregation of chromosomes during mitosis. Like chromosomes, the centrosome inherited from the progenitor cell duplicates once in each division cycle, following which the sister centrosomes segregate away from each other to assemble a short spindle upon initiation of mitosis. Cdh1, an activator of the E3 ubiquitin ligase APC (Anaphase Promoting Complex), is a potent inhibitor of centrosome segregation and suppresses spindle assembly during S phase by mediating proteolytic destruction of the microtubule associated proteins (MAPs) required for centrosome separation. A recent study in yeast suggests that concerted action by two prominent kinases Cdk1 and polo are required to bring this destruction to a halt by inactivating Cdh1 and to facilitate spindle assembly. This is an effective strategy for the modulation of the activities of cell cycle regulators that require multiple phosphorylation. The control circuit involving Cdh1, Cdk1, Polo and MAPs may be also targeted by other cellular networks in contexts that demand the restraining of spindle dynamics.
authors.affiliation: Institute of Molecular and Cell Biology, A *STAR, 61, Biopolis Drive, Proteos, Singapore, Singapore.
authors.forename: Karen
authors.initials: K
authors.lastname: Crasta
authors.forename: Hong Hwa
authors.initials: HH
authors.lastname: Lim
authors.forename: Tao
authors.initials: T
authors.lastname: Zhang
authors.forename: Saurabh
authors.initials: S
authors.lastname: Nirantar
authors.forename: Uttam
authors.initials: U
authors.lastname: Surana
mesh_terms: D064173:Anaphase-Promoting Complex-Cyclosome; D000818:Animals; D016203:CDC2 Protein Kinase / Q000235:genetics / Q000378:metabolism; D015820:Cadherins / Q000235:genetics / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D008954:Models, Biological; D010766:Phosphorylation; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D008941:Spindle Apparatus / Q000378:metabolism*; D043743:Ubiquitin-Protein Ligase Complexes / Q000378:metabolism
chemical_list: D015820:Cadherins; D018797:Cell Cycle Proteins; D043743:Ubiquitin-Protein Ligase Complexes; D064173:Anaphase-Promoting Complex-Cyclosome; D011494:Protein Kinases; D016203:CDC2 Protein Kinase