Altered substrate selectivity of PKC-eta pseudosubstrate site mutants.

Three protein kinase C (PKC)-eta mutants were constructed in which the whole or part of the pseudosubstrate site was replaced with corresponding parts of the PKC-alpha pseudosubstrate site. The resulting chimaeric kinases were compared with wild-type PKC-eta in their ability to phosphorylate a PKC-eta peptide substrate or histone. Changes in the pseudosubstrate site of PKC-eta are accompanied by changes in substrate selectivity, indicating that the substrate selectivity observed for PKC-eta is at least in part due to its pseudosubstrate site.