Purification and proteomic identification of putative upstream regulators of polo-like kinase-1 from mitotic cell extracts.
Polo-like kinase-1 (Plk1) is phosphorylated on Thr210 for activation during mitosis. Here, we investigated the question of which kinase(s) is the specific upstream kinase of mitotic Plk1. Upstream kinases of Plk1 were purified from mitotic cell extracts through column chromatography procedures, and identified by mass spectrometry. Candidates for Plk1 kinase included p21-activated kinase, aurora A, and mammalian Ste20-like kinases. Immunoprecipitates of these proteins from mitotic cell extracts phosphorylated Plk1 on Thr210. Even if the activity of Aurora A was blocked with a specific inhibitor, Plk1 phosphorylation still occurred, suggesting that function of Plk1 could be controlled by these kinases for proper mitotic progression, as well as by Aurora A in very late G2 phase for the beginning of mitosis.
Ji
Jae-Hoon
JH
Laboratory of Cell Cycle and Signal Transduction, WCU Department of NanoBioMedical Science, Dankook University, Cheonan-Si, Chungnam, Republic of Korea.
Hwang
Hyo-In
HI
Lee
Hee-Jae
HJ
Hyun
Sun-Yi
SY
Kang
Hoe-Jin
HJ
Jang
Young-Joo
YJ
D000818:Animals; D064127:Aurora Kinases; D015153:Blotting, Western; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D002457:Cell Extracts / Q000737:chemistry*; D002460:Cell Line; D045744:Cell Line, Tumor; D006367:HeLa Cells; D006801:Humans; D008938:Mitosis; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D040901:Proteomics / Q000379:methods*; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D018411:Spodoptera; D013912:Threonine / Q000378:metabolism; D054462:p21-Activated Kinases / Q000378:metabolism; D000097869:Polo-Like Kinase 1
D064127:Aurora Kinases; D018797:Cell Cycle Proteins; D002457:Cell Extracts; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D011994:Recombinant Proteins; D013912:Threonine; D054462:p21-Activated Kinases; D000097869:Polo-Like Kinase 1