Deficiency in chromosome congression by the inhibition of Plk1 polo box domain-dependent recognition.
Polo-like kinase 1 (Plk1) is one of the key regulators of mitotic cell division. In addition to an N-terminal protein kinase catalytic domain, Plk1 possesses a phosphopeptide binding domain named polo box domain (PBD) at its C terminus. PBD is postulated to be essential for Plk1 localization and substrate targeting. Here, we developed a high-throughput screening system to identify inhibitors of PBD-dependent binding and screened a chemical library. We isolated a benzotropolone-containing natural compound derived from nutgalls (purpurogallin (PPG)) that inhibited PBD-dependent binding in vitro and in vivo. PPG not only delayed the onset of mitosis but also prolonged the progression of mitosis in HeLa cells. Although apparently normal bipolar spindles were formed even in the presence of PPG, the perturbation of chromosome alignment at metaphase plates activated the spindle assembly checkpoint pathway. These results demonstrate the predominant role of PBD-dependent binding on smooth chromosome congression at metaphase.
Watanabe
Nobumoto
N
Chemical Biology Department, Antibiotics Laboratory, Advanced Science Institute, RIKEN, 2-1, Hirosawa, Wako, Saitama 351-0198, Japan. nwatanab@riken.jp
Sekine
Tomomi
T
Takagi
Masatoshi
M
Iwasaki
Jun-ichi
J
Imamoto
Naoko
N
Kawasaki
Hisashi
H
Osada
Hiroyuki
H
D018797:Cell Cycle Proteins / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism*; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism; D002877:Chromosomes, Human / Q000235:genetics* / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D018386:Kinetochores / Q000378:metabolism; D008870:Microtubules / Q000378:metabolism; D008938:Mitosis / Q000187:drug effects; D015394:Molecular Structure; D011485:Protein Binding; D047428:Protein Kinase Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism*; D000097869:Polo-Like Kinase 1
D018797:Cell Cycle Proteins; D002868:Chromosomal Proteins, Non-Histone; D047428:Protein Kinase Inhibitors; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D000097869:Polo-Like Kinase 1; C068688:centromere protein E