Plk2 regulated centriole duplication is dependent on its localization to the centrioles and a functional polo-box domain.
In mammalian cells, the centrosome consists of a pair of centrioles and amorphous pericentriolar material. The centrosome duplicates once per cell cycle. Polo like kinases (Plks) perform crucial functions in cell cycle progression and during mitosis. The polo-like kinase-2, Plk2, is activated near the G(1)/S phase transition, and plays an important role in the reproduction of centrosomes. In this study, we show that the polo-box of Plk2 is required both for association to the centrosome and centriole duplication. Mutation of critical sites in the Plk2 polo-box prevents centrosomal localization and impairs centriole duplication. Plk2 is localized to centrosomes during early G(1) phase where it only associates to the mother centriole and then distributes equally to both mother and daughter centrioles at the onset of S phase. Furthermore, our results imply that Plk2 mediated centriole duplication is dependent on Plk4 function. In addition, we find that siRNA-mediated downregulation of Plk2 leads to the formation of abnormal mitotic spindles confirming that Plk2 may have a function in the reproduction of centrioles.
Cizmecioglu
Onur
O
Cell cycle Control and Carcinogenesis (F045), German Cancer Research Center (DKFZ), Heidelberg, Germany.
Warnke
Silke
S
Arnold
Marc
M
Duensing
Stefan
S
Hoffmann
Ingrid
I
D001665:Binding Sites; D002453:Cell Cycle; D048750:Cell Nucleus Division; D002502:Centrioles; D018385:Centrosome; D016193:G1 Phase; D006801:Humans; D008938:Mitosis; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism / Q000502:physiology*; D034741:RNA, Small Interfering / Q000494:pharmacology; D008941:Spindle Apparatus / Q000187:drug effects
D034741:RNA, Small Interfering; C490219:PLK4 protein, human; C496126:PLK2 protein, human; D017346:Protein Serine-Threonine Kinases