Mitogen-activated protein kinase kinase kinase 1, also known as MEKK1, MAPKKK1, MEK Kinase or MAP/ERK Kinase Kinase 1, is an enzyme that in humans is encoded by the MAP3K1 gene. Vinik et al.(1995) identified DNA sequence and size polymorphisms in intronic and 3-prime untranslated regions of the mouse gene and the human homolog. Using these allele-specific polymorphisms, they mapped the mouse gene in an intersubspecific backcross to chromosome 13. They mapped the human gene to chromosome 5 by somatic cell hybrid analysis. By assaying transfected COS-1 cells, Xia et al.(1998) showed that human MAP3K1 / MEKK1 activated JNK1 (MAPK8) robustly and p38-alpha (MAPK14) less efficiently, but it had only a marginal effect on ERK2 (MAPK1). MAP3K1 / MEKK1 directly and specifically interacted with JNKK1 (MAP2K4) and activated JNKK1 in cells and in vitro. Phosphorylation of JNKK1 disrupted their interaction. MEKK1 and JNK1 competed for binding to JNKK1. Xia et al.(1998) concluded that JNKK1 is the preferred MEKK1 substrate.
The stated application concentrations are suggested starting amounts. Titration of the MAP3K1 antibody may be required due to differences in protocols and secondary/substrate sensitivity.\. Western blot: 0.5-1 μg/mL,IHC (Paraffin): 0.5-1 μg/mL