Binding of 14-3-3 proteins to the protein kinase Raf and effects on its activation.
To identify proteins that may participate in the activation of the protein kinase Raf, proteins that interact with Raf were selected in a two-hybrid screen. Two members of the 14-3-3 protein family were isolated that interacted with both the amino terminal regulatory regions of Raf and the kinase domain of Raf, but did not compete with the guanine nucleotide-binding protein Ras for binding to Raf. 14-3-3 proteins associated with Raf in mammalian cells and accompanied Raf to the membrane in the presence of activated Ras. In yeast cells expressing Raf and MEK, mammalian 14-3-3 beta or 14-3-3 zeta activated Raf to a similar extent as did expression of Ras. Therefore, 14-3-3 proteins may participate in or be required for the regulation of Raf function. These findings suggest a role for 14-3-3 proteins in Raf-mediated signal transduction.
Freed
E
E
Onyx Pharmaceuticals, Richmond, CA 94806-5206.
Symons
M
M
Macdonald
S G
SG
McCormick
F
F
Ruggieri
R
R
D048948:14-3-3 Proteins; D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D002462:Cell Membrane / Q000201:enzymology; D003600:Cytosol / Q000201:enzymology; D004789:Enzyme Activation; D019204:GTP-Binding Proteins / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D048369:MAP Kinase Kinase 1; D020929:Mitogen-Activated Protein Kinase Kinases; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011505:Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000737:chemistry / Q000378:metabolism*; D019908:Proto-Oncogene Proteins c-raf; D011994:Recombinant Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000254:growth & development; D015398:Signal Transduction; D014446:Tyrosine 3-Monooxygenase; D016335:Zinc Fingers
D048948:14-3-3 Proteins; D009419:Nerve Tissue Proteins; D011518:Proto-Oncogene Proteins; D011994:Recombinant Proteins; D014446:Tyrosine 3-Monooxygenase; D011505:Protein-Tyrosine Kinases; D017346:Protein Serine-Threonine Kinases; D019908:Proto-Oncogene Proteins c-raf; D048369:MAP Kinase Kinase 1; C482125:MAP2K1 protein, human; D020929:Mitogen-Activated Protein Kinase Kinases; D019204:GTP-Binding Proteins