Mammalian Ras interacts directly with the serine/threonine kinase Raf.
We have identified proteins that interact with H-Ras using a two hybrid system screen of a mouse cDNA library. Approximately 50% of the clones identified encoded portions of the c-Raf and A-Raf serine/threonine kinases. Overlaps among these clones define a conserved 81 residue region of the N-terminus of Raf as the Ras interaction region. We show that Raf interacts with wild-type and activated Ras, but not with an effector domain mutant of Ras or with a dominant-interfering Ras mutant. Using purified bacterially expressed fusion proteins, we show, furthermore, that Ras and the N-terminal region of Raf associate directly in vitro and that this interaction is dependent on GTP bound to Ras.
Vojtek
A B
AB
Fred Hutchinson Cancer Research Center, Seattle, Washington 98104.
Hollenberg
S M
SM
Cooper
J A
JA
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D004247:DNA; D011905:Genes, ras; D006160:Guanosine Triphosphate / Q000378:metabolism*; D051379:Mice; D008969:Molecular Sequence Data; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D019908:Proto-Oncogene Proteins c-raf; D016283:Proto-Oncogene Proteins p21(ras) / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae; D017386:Sequence Homology, Amino Acid
D011518:Proto-Oncogene Proteins; D011993:Recombinant Fusion Proteins; D006160:Guanosine Triphosphate; D004247:DNA; D017346:Protein Serine-Threonine Kinases; D019908:Proto-Oncogene Proteins c-raf; D016283:Proto-Oncogene Proteins p21(ras)