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 correspon ding parts of the PKC-alpha pseudosubstrate site. The resulting chimae ric kinases were compared with wild-type PKC-eta in their ability to p hosphorylate a PKC-eta peptide substrate or histone. Changes in the ps eudosubstrate site of PKC-eta are accompanied by changes in substrate selectivity, indicating that the substrate selectivity observed for PK C-eta is at least in part due to its pseudosubstrate site.