PAK1 (1 μg)

Source: Recombinant human produced GST-tagged in E. coli

Purity: ~ 90% by SDS-PAGE, apparent Mr ~ 100-kDa.

Supplied: 1 μg in 50 μl 50 mM Tris-HCl pH 7.0 buffer containing 14 mM β-mercaptoethanol, 1 mM benzamidine, 0.1 mM phenylmethanesulfonyl fluoride, 1 mM EDTA, 0.03% Brij-35 and 10% glycerol.

Activity: ~ 200 units/mg with myelin basic protein (MBP) as substrate measured in the absence of Cdc42. One unit is the amount of PAK1 that incorporates 1 nmol of phosphate into MBP per min. Maintain preparations in aliquots at -70° C. Avoid repeated thawing.

Synonyms: GST-PAK1; GST-p65PAK; GST-p68PAK; GST p21-Activated Protein Kinase

Background: PAK1 is a 65- to 68-kDa Group I member of the protein serine/threonine kinase family whose activity is stimulated by the binding of active Rac and Cdc42 Rho family small GTPases. The PAK enzymes are involved in regulating cell morphology and cytoskeleton organization, cell motility, apoptosis, neuronal functions, cell cycle progression, viral replication and numerous other processes. PAK1 has a C-terminus kinase domain and N-terminus Rac- and Cdc42-binding domain. Binding of Rac and Cdc42 (GLO128-005, GLO128-025, GLO128-050) results in the autophosphorylation and concomitant activation of the kinase, which is then thought to dissociate from the G-proteins to act on down stream targets.

Such targets include p38 MAP kinase, JNK, Raf1 and Synapsin I. PAK’s have also been found to interact with protein phosphatase 2A (GLO130-GLO132), ribosomal protein S6 kinase, mxed lineage kinase (MLK2), the SH3-SH2 adapter Nck and m any other regulatory proteins. The catalytic domains of PAK family members are produced in apoptotic cells via a caspase-dependent pathway.  Unlike the native enzymes, the catalytic domains are unaffected by Rac and Cdc42. They undergo rapid autophosphorylation and marked activation.