The P21-Activated Protein Kinases (Paks) Receive And Integrate Messages From A Variety of Signaling Pathways
Neutrophils stimulated with leukotriene B4, platelet activating factor or a variety of other chemoattractants that bind to G-protein coupled serpentine receptors exhibit rapid activation of two p21-activated kinases (Paks) with molecular masses of ca 63 and 69 kDa (y-and a- Pak)1.2.3 The 63 and 69 kDa Paks are ser/thr protein kinases that preferentially recognize the consensus sequence - (K/R)RX(S/T)- where X can be an acidic, basic or neutral amino acid4. These kinases can be conveniently assayed in neutrophils by their ability to undergo renaturation after separation by SDS/PAGE and undergoing autophosphorylation5 or catalyzing the phosphorylation of a peptide substrate fixed within a gel that corresponds to amino acid residues 297-331 of the 47 kDa subunit of the NADPH-oxidase complex (p47-phox) 1 .Histone H4 can also serve as a highly specific substrate for these enzymes in “in gel” assays5.
KeywordsTyrosine Serine Saccharomyces Guanine Ceramide
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