The MCK enhancer contains a p53 responsive element

p53 is an antioncogene that is defective or absent in a large number of human tumors. Its function in normal cells is not known. We show that co-transfection of mouse p53 with muscle-specific creatine kinase-chloramphenicol acetyltransferase reporter gene, containing 3.3 kilobase of upstream control sequence for the muscle-specific creatine kinase gene, results in a 10- to 80-fold activation. The p53 responsive element maps to a region distinguished from the known MyoD binding region. Identification of a p53 responsive element should allow a more focused analysis of the effects of p53 in controlling gene activity.