mouse monoclonal IgG1; p-MEK-3/6 Antibody (B-9) is an IgG1 κ mouse monoclonal p-MEK-3/6 antibody that detects MEK-3 and MEK-6 phosphorylated at Ser 189 and Ser 207 of mouse, rat and human origin by WB, IP, IF, IHC(P) and ELISA. p-MEK-3/6 Antibody (B-9) is available as the non-conjugated anti-p-MEK-3/6 antibody form, as well as multiple conjugated forms of anti-p-MEK-3/6 antibody, including agarose, HRP, PE, FITC and multiple Alexa Fluor® conjugates. A family of protein kinases located upstream of the MAP kinases and responsible for their activation has been identified. The prototype member of this family, designated MAP kinase kinase, or MEK-1, specifically phosphorylates the MAP kinase regulatory threonine and tyrosine residues present in the Thr-Glu-Tyr motif of ERK. A second MEK family member, MEK-2, resembles MEK-1 in its substrate specificity. MEK-3 (or MKK-3) functions to activate p38 MAP kinase, and MEK-4 (also called SEK1 or MKK-4) activates both p38 and JNK MAP kinases. MEK-5 appears to specifically phosphorylate ERK5, whereas MEK-6 phosphorylates p38 and p38b. MEK-7 (or MKK-7) phosphorylates and activates the JNK signal transduction pathway (7-9).