Cdc2-independent induction of premature mitosis by okadaic acid in HeLa cells.
The induction of premature mitosis by okadaic acid (OA) in HeLa cells in S-phase or in G2-phase has been studied using light microscopy, immunofluorescence, and immunochemical techniques. The observations indicate an involvement of a cdc2-independent pathway in these cells. It has been claimed that inhibition of an OA-sensitive phosphatase, possibly of PP1, induces activation of a kinase which is sensitive to staurosporine and Zn2+. This kinase brings about mitosis-specific cytoskeletal rearrangements, chromosome condensation, and nuclear envelope breakdown, inducing a mitosis-like state. However, other mitotic events do not follow. The possibility that this kinase may be a NIMA-like Nek2 kinase is discussed.
Division of Growth, German Cancer Research Center, Heidelberg, Germany.
S
S
Ghosh
N
N
Paweletz
D
D
Schroeter
D016203:CDC2 Protein Kinase / Q000502:physiology*; D002193:Cantharidin / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D016195:G2 Phase; D006367:HeLa Cells; D006801:Humans; D008938:Mitosis / Q000187:drug effects*; D000072379:NIMA-Related Kinases; D019319:Okadaic Acid / Q000494:pharmacology*; D010749:Phosphoprotein Phosphatases / Q000037:antagonists & inhibitors / Q000502:physiology*; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors / Q000502:physiology; D016196:S Phase
D004791:Enzyme Inhibitors; D019319:Okadaic Acid; C089441:NEK2 protein, human; D000072379:NIMA-Related Kinases; D017346:Protein Serine-Threonine Kinases; D016203:CDC2 Protein Kinase; D010749:Phosphoprotein Phosphatases; D002193:Cantharidin