Description_x000D_ General description_x000D_ MOS or v-mos Moloney murine sarcoma viral oncogene homolog is a serine/threonine kinase that activate the MAP kinase cascade through direct phosphorylation of the MAP kinase activator MEK. The early site-specific phosphorylation of CPEB , which was catalyzed by Eg2 is essential for the polyadenylation of c-mos mRNA, subsequent translation of c-mos, and oocyte maturation. The interaction with and phosphorylation of MYOD by MOS enhances muscle differentiation. MOS is an essential component of the cytostatic factor that acts almost exclusively in the second meiotic metaphase arrest._x000D_ Physical form_x000D_ Supplied in 50 mM Tris-HCl, pH 7.5, 150 mM NaCl, 10 mM glutathione, 0.1 mM EDTA, 0.25 mM DTT, 0.1 mM PMSF, 25% glycerol._x000D_ Preparation Note_x000D_ After opening, aliquot into smaller quantities and store at -70 °C. Avoid repeating handling and multiple freeze/thaw cycles.