Polo-like kinase-2 is required for centriole duplication in mammalian cells.
Centriole duplication initiates at the G1-to-S transition in mammalian cells and is completed during the S and G2 phases. The localization of a number of protein kinases to the centrosome has revealed the importance of protein phosphorylation in controlling the centriole duplication cycle. Here we show that the human Polo-like kinase 2 (Plk2) is activated near the G1-to-S transition of the cell cycle. Endogenous and overexpressed HA-Plk2 localize with centrosomes, and this interaction is independent of Plk2 kinase activity. In contrast, the kinase activity of Plk2 is required for centriole duplication. Overexpression of a kinase-deficient mutant under S-phase arrest blocks centriole duplication. Downregulation of endogenous Plk2 with small hairpin RNAs interferes with the ability to reduplicate centrioles. Furthermore, centrioles failed to duplicate during the cell cycle of human fibroblasts and U2OS cells after overexpression of a Plk2 dominant-negative mutant. These results show that Plk2 is a physiological centrosomal protein and that its kinase activity is likely to be required for centriole duplication near the G1-to-S phase transition.
Warnke
Silke
S
Cell Cycle Control and Carcinogenesis, F045, German Cancer Research Center DKFZ, Im Neuenheimer Feld 242, D-69120 Heidelberg, Germany.
Kemmler
Stefan
S
Hames
Rebecca S
RS
Tsai
Hsiao-Lun
HL
Hoffmann-Rohrer
Urs
U
Fry
Andrew M
AM
Hoffmann
Ingrid
I
D000818:Animals; D015153:Blotting, Western; D002453:Cell Cycle / Q000502:physiology*; D018797:Cell Cycle Proteins / Q000378:metabolism* / Q000502:physiology; D002478:Cells, Cultured / Q000166:cytology; D002502:Centrioles / Q000502:physiology*; D018385:Centrosome / Q000378:metabolism / Q000502:physiology*; D019927:Cyclin E; D017931:DNA Primers; D005455:Fluorescent Antibody Technique; D005786:Gene Expression Regulation; D006367:HeLa Cells / Q000166:cytology; D006801:Humans; D008322:Mammals; D010957:Plasmids / Q000235:genetics; D011233:Precipitin Tests; D011494:Protein Kinases; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism* / Q000502:physiology; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics; D029867:Xenopus Proteins / Q000378:metabolism* / Q000502:physiology
D018797:Cell Cycle Proteins; D019927:Cyclin E; D017931:DNA Primers; D034741:RNA, Small Interfering; D029867:Xenopus Proteins; D011494:Protein Kinases; C438873:PlK2 protein, Xenopus; C102333:histone H1 kinase; D017346:Protein Serine-Threonine Kinases