Human PAK1 Antibody

PAK1 (p21-activaed kinase 1; also alpha-PAK and p65-PAK) is both a cytoplasmic and nuclear 58-60 kDa member of PAK group I, STE20 subfamily, STE Ser/Thr protein kinase family of molecules. It is widely expressed, and is upregulated in numerous cancers. PAK1 has multiple activities. It is responsible for regulating focal adhesions during motility. At the front edge of cells, PAK1 promotes focal adhesion formation by phosphorylating PIX, while at the back edge, it directs focal adhesion disassembly. PAK1 also impacts microtubule formation. Microtubules are composed of heterodimeric subunits containing an alpha- and beta-tubulin polypeptide. The availability of alpha-tubulin for microtubule formation is based on the ability of PAK1 to phosphorylate a alpha-tubulin chaperone, tubulin cofactor B. PAK1 is activated following binding to active GTPases which induce PAK autophosphorylation. When active, PAK1 is a monomer; when inactive, it reportedly homodimerizes. Human PAK1 is 545 amino acids (aa) in length. It contains one GTPase binding domain (aa 75-105) plus a protein kinase catalytic region (aa 250-521). There are five SH3-binding motifs. Acetylation occurs on Lys256, and there are at least 14 potential phosphorylation sites, seven of which are known to be utilized. There is one splice variant that shows a 35 aa substitution for aa 518-545. Over aa 128-242, human PAK1 shares 96% aa sequence identity with mouse PAK1.