The mitotic phosphatase cdc25C at the Golgi apparatus.
cdc25C is a phosphatase which regulates the activity of the mitosis promoting factor cyclin B/cdk1 by dephosphorylation, thus triggering G(2)/M transition. The activity of cdc25C is regulated by phosphorylation which by itself is implicated in regulating the subcellular localization. It is well accepted that cdc25C has to enter the nucleus to activate the cyclin B/cdk1 complex at G(2)/M transition. Here, we will show that cdc25C is located in the cytoplasm at defined dense structures which by immunofluorescence analysis as well as by biochemical subfractionation turned out to be the Golgi apparatus. It will be further shown that cdc25C at the Golgi fraction is an active phosphatase suggesting an additional and new role of cdc25C at the Golgi apparatus.
Noll
Andreas
A
Medizinische Biochemie und Molekularbiologie, Universität des Saarlandes, Gebäude 44, 66424 Homburg, Germany.
Ruppenthal
Sandra L
SL
Montenarh
Mathias
M
D018797:Cell Cycle Proteins / Q000032:analysis* / Q000378:metabolism*; D003593:Cytoplasm / Q000201:enzymology / Q000648:ultrastructure; D006056:Golgi Apparatus / Q000201:enzymology*; D006801:Humans; D008938:Mitosis; D020687:cdc25 Phosphatases / Q000032:analysis* / Q000378:metabolism*
D018797:Cell Cycle Proteins; C517009:CDC25C protein, human; D020687:cdc25 Phosphatases