Phosphorylation can both positively and negatively regulate activity of the Raf kinases. Akt
has been shown to phosphorylate and inhibit C-Raf activity. We have recently reported that
Akt negatively regulates B-Raf kinase activation by phosphorylating multiple residues within
its amino-terminal regulatory domain. Here we investigated the regulation of B-Raf byserum
and glucocorticoid-induciblekinase, SGK, which shares close sequence identity with the
catalytic domain of Akt but lacks the pleckstrin homology domain. We observed that SGK …