title: Phosphorylation of wild-type and mutant phenotypes of p53 by an associated protein-kinase.
abstract: Immunopurified mutant mouse p53 from transformed cells is known to be tightly associated with a protein kinase which phosphorylates p53 in an in vitro kinase reaction. Wild-type p53 from a non-transformed cell line was not associated with a protein kinase whereas immunopurified wild-type p53 from a transformed cell line was tightly associated with a protein kinase which phosphorylated p53. In order to compare wild-type and mutant p53 in the same cellular environment both forms were cloned in a baculovirus expression system and in in vitro transcription/translation vectors and both p53 proteins were expressed in the two systems. Wild-type and mutant p53 from baculovirus infected insect cells were tightly associated with a protein kinase which phosphorylates p53. In contrast, immunopurified wild-type and mutant p53 from an in vitro transcription/translation reaction were not associated with a protein kinase but could be phosphorylated by added casein kinase II. Thus, in the present paper we demonstrate that the association of p53 with a protein kinase and the in vitro phosphorylation of p53 seems to depend on the surrounding cellular environment.
authors.affiliation: UNIV SAARLAND,GEBAUDE 44,W-6650 HOMBURG,GERMANY. UNIV SAARLAND,INST HUMAN GENET,W-6650 HOMBURG,GERMANY.
authors.forename: A
authors.initials: A
authors.lastname: Lorenz
authors.forename: C
authors.initials: C
authors.lastname: Herrmann
authors.forename: O
authors.initials: O
authors.lastname: Issinger
authors.forename: M
authors.initials: M
authors.lastname: Montenarh