Description_x000D_ General description_x000D_ MLK1 or Mixed-Lineage Kinase 1 is a mitogen-activated protein kinase kinase kinase capable of activating the c-Jun NH(2)-terminal kinase (JNK) pathway. The catalytic domain of MLK1 has amino acid sequence similarity to both the tyr-specific and the ser/thr-specific kinase classes. In addition, MLK1 contain 2 leu/ile-zipper motifs and a basic sequence near its C-termini. MLK1 is threonine (and possibly serine) phosphorylated at multiple sites in the activation loop, with phosphorylation of Thr312 required for full activation._x000D_ Physical form_x000D_ Supplied in 50mM Tris-HCl, pH 7.5, 150mM NaCl, 10mM glutathione, 0.1mM EDTA, 0.25mM DTT, 0.1mM 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_x000D_ Legal Information_x000D_ PRECISIO is a registered trademark of Sigma-Aldrich Co. LLC