TI  -  14-3-3  proteins associate with  <prot>cdc25</prot> phosphatases .
PG  - 7892-6
AB  - The  <prot>cdc25</prot>  phosphatases play key roles in cell cycle progression by
      activating  cyclin-dependent kinases . Two members of the 14-3-3 protein
      family have been isolated in a yeast two-hybrid screen designed to
      identify proteins that interact with the human cdc25A and cdc25B
      phosphatases. Genes encoding the human homolog of the 14-3-3 epsilon
      protein and the previously described 14-3-3 beta protein have been
      isolated in this screening. 14-3-3 proteins constitute a family of
      well-conserved eukaryotic proteins that were originally isolated in
      mammalian brain preparations and that possess diverse biochemical
      activities related to signal transduction. We present evidence that
      indicates that  <prot>cdc25</prot>  and  14-3-3  proteins physically interact both in vitro
      and in vivo. 14-3-3 protein does not, however, affect the phosphatase
      activity of cdc25A.   <prot>Raf-1</prot>  , which is known to bind  14-3-3  proteins, has
      recently been shown to associate with  <prot>cdc25A</prot>  and to stimulate its
      phosphatase activity. 14-3-3 protein, however, has no effect on the
       <prot>cdc25A</prot>-kinase  activity of  <prot>Raf-1</prot> . Instead, 14-3-3 may facilitate the
      association of  <prot>cdc25</prot>  with  <prot>Raf-1</prot>  in vivo, participating in the linkage
      between mitogenic signaling and the cell cycle machinery.
AD  - Howard Hughes Medical Institute, Cold Spring Harbor Laboratory, NY 11724,
