IndraLab
Statements
"Among other effectors, active ras binds and activates the raf kinase, iniziating a kinase cascade involving serine phosporylation of mek1/2 (mapkk) and tyrosine and threonine phosphorylation of erk1/2 ras activation leads to raf and subsequently mek activation. Phospholipide analysis demostrated that serine residues 218 and 222 of human mek1 are the primary sites for phosphorylation by c-raf."
rlimsp
"This strategy revealed that MEK1 is constitutively and mainly phosphorylated at the Thr-292, Ser-298, Thr-386, and Thr-388 residues in vivo, and that combinations of phosphorylations at these four residues produce at least six phosphorylated variants of MEK1. Like the levels of phosphorylation of the Ser-218 and Ser-222 residues by RAF1, which have been well studied, the phosphorylation statuses of Thr-292, Ser-298, Thr-386, and Thr-388 residues vary widely during activation and deactivation of the MAPK pathway."