WARTS tumor suppressor is phosphorylated by Cdc2/cyclin B at spindle poles during mitosis.
Identification of physiological substrates for Cdc2/cyclin B is crucial for understanding the functional link between mitotic events and Cdc2/cyclin B activation. A human homologue of the Drosophila warts tumor suppressor, termed WARTS, is a serine/threonine kinase and a dynamic component of the mitotic apparatus. We have found that Cdc2/cyclin B forms a complex with a fraction of WARTS in the centrosome and phosphorylates the Ser613 site of WARTS during mitosis. Immunocytochemical analysis has shown that the S613-phosphorylated WARTS appears in the spindle poles at prometaphase and disappears at telophase. Our findings suggest that Cdc/cyclin B regulates functions of WARTS on the mitotic apparatus.
Morisaki
Tetsuro
T
Department of Tumor Genetics and Biology, Kumamoto University School of Medicine, 2-2-1 Honjo, Kumamoto 860-0811, Japan.
Hirota
Toru
T
Iida
Shin-ichi
S
Marumoto
Tomotoshi
T
Hara
Toshihiro
T
Nishiyama
Yasuyuki
Y
Kawasuzi
Michio
M
Hiraoka
Takehisa
T
Mimori
Tatsuyuki
T
Araki
Norie
N
Izawa
Ichiro
I
Inagaki
Masaki
M
Saya
Hideyuki
H
D000595:Amino Acid Sequence; D015153:Blotting, Western; D016203:CDC2 Protein Kinase / Q000378:metabolism*; D002850:Chromatography, Gel; D019926:Cyclin B / Q000378:metabolism*; D029721:Drosophila Proteins; D016147:Genes, Tumor Suppressor; D006367:HeLa Cells; D006801:Humans; D008856:Microscopy, Fluorescence; D008938:Mitosis; D010766:Phosphorylation; D011233:Precipitin Tests; D011494:Protein Kinases; D017346:Protein Serine-Threonine Kinases / Q000276:immunology / Q000378:metabolism*; D008941:Spindle Apparatus; D013347:Subcellular Fractions / Q000378:metabolism; D013379:Substrate Specificity
C503698:CycB protein, Drosophila; D019926:Cyclin B; D029721:Drosophila Proteins; D011494:Protein Kinases; C092745:LATS1 protein, human; C093503:wts protein, Drosophila; D017346:Protein Serine-Threonine Kinases; D016203:CDC2 Protein Kinase