Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published September 6, 1996 | public
Journal Article

Purification and Molecular Cloning of Plx1, a Cdc25-Regulatory Kinase from Xenopus Egg Extracts

Abstract

Cdc2, the cyclin-dependent kinase that controls mitosis, is negatively regulated by phosphorylation on its threonine-14 and tyrosine-15 residues. Cdc25, the phosphatase that dephosphorylates both of these residues, undergoes activation and phosphorylation by multiple kinases at mitosis. Plx1, a kinase that associates with and phosphorylates the amino-terminal domain of Cdc25, was purified extensively from Xenopus egg extracts. Cloning of its complementary DNA revealed that Plx1 is related to the Polo family of protein kinases. Recombinant Plx1 phosphorylated Cdc25 and stimulated its activity in a purified system. Cdc25 phosphorylated by Plx1 reacted strongly with MPM-2, a monoclonal antibody to mitotic phosphoproteins. These studies indicate that Plx1 may participate in control of mitotic progression.

Additional Information

© 1996 American Association for the Advancement of Science. Received 15 May 1996; accepted 15 July 1996. We thank members of the Dunphy lab for comments on the manuscript, P. R. Mueller for the Xenopus oocyte cDNA library, and D. S. Krapf and G. Hathaway for peptide sequencing. Supported in part by a grant from NIH. W.G.D. is an investigator of the Howard Hughes Medical Institute.

Additional details

Created:
August 19, 2023
Modified:
October 18, 2023