IndraLab
Statements
"Using mass spectrometry, we identified raf-1 phosphorylation on three sp motif sites: s289/s296/s301. These sites were phosphorylated by extracellular signal-regulated kinase (erk)-1 in vitro, and their phosphorylation in vivo was dependent on endogenous erk activity. Functionally, erk-1 expression sustains raf-1 activation in a manner dependent on raf-1 phosphorylation on the identified sites, and s289/296/301a substitution markedly decreases the in vivo activity of raf-1 s259a."
"Here, we identify six residues of Raf-1 (S29, S43, S289, S296, S301, and S642) that become hyperphosphorylated in a manner coincident with Raf-1 inactivation. | Five of the identified sites are proline-directed targets of activated ERK, and phosphorylation of all six sites requires MEK signaling, indicating a negative feedback mechanism. Hyperphosphorylation of these six sites inhibits the Ras/Raf-1 interaction and desensitizes Raf-1 to additional stimuli.|FLAG-Raf-1 phosphorylated by activated ERK2"
"Using mass spectrometry, we identified raf-1 phosphorylation on three sp motif sites: s289/s296/s301. These sites were phosphorylated by extracellular signal-regulated kinase (erk)-1 in vitro, and their phosphorylation in vivo was dependent on endogenous erk activity. Functionally, erk-1 expression sustains raf-1 activation in a manner dependent on raf-1 phosphorylation on the identified sites, and s289/296/301a substitution markedly decreases the in vivo activity of raf-1 s259a."