SAPK/Erk kinase (SEK1), also known as MKK4 or Jun kinase kinase (JNKK), activates the MAP kinase homologues SAPK and JNK in response to various cellular stresses and inflamatory cytokines (1-3). Activation of SEK1 occurs through MEKK phosphorylation of serine and threonine residues at positions 257 and 261, respectively. Like MEK, SEK is a dual-specificity protein kinase that phosphorylates SAPK/JNK at a conserved T*PY* site in its activation loop (4). Phosphorylation by Akt at Ser80 inhibits SEK1 and suppresses stress-activated signal transduction (5).1) Davis, R. J. (1994) Trends Biochem. Sci. 19, 470-473. Sanchez, I. et al. (1994) Nature 372, 794-798. Yan, M. et al. (1994) Nature 372, 798-800. Kyriakis, J. M. et al. (1994) Nature 369, 156-160. Park, H. et al. (2002) J. Biol. Chem. 277, 2573-2578.
Immunogen
MAP2K4 antibody was raised against a peptide sequence around aa.352~356 (E-S-K-R-P) derived from Human MAP2K4. .