MEKK3 Antibody

MAP3K3 (Mitogen-activated protein kinase kinase kinase 3), also known as MAP/ERK kinase kinase 3 (Mekk3), or MAPKKK3, is an enzyme that in humans is encoded by the MAP3K3 gene. MAP3K3 is contiguously distal to LYK5 on chromosome 17 (Puffenberger et al., 2007) . By yeast 2-hybrid analysis of a mouse T-cell cDNA library, Uhlik et al. (2003) showed that a C-terminal fragment of mouse Osm (CCM2) interacted with MAP3K3/Mekk3, which activates p38 in response to sorbitol-induced hyperosmotic conditions. Mekk3 and Osm colocalized in the cytoplasmic compartment of cotransfected cells, and the Mekk3-Osm complex was recruited to Rac1 and cytoskeletal actin-containing membrane ruffles in response to sorbitol treatment. Protein interaction assays showed that Osm interacted directly with the Mekk3 substrate Mkk3 (MAP2K3), with actin, and with both GDP- and GTP-loaded Rac1. Uhlik et al. (2003) concluded that the RAC1-OSM-MEKK3-MKK3 complex is required for regulation of p38 activity in response to osmotic shock.