Lorenz A, Herrmann C, Issinger O, Montenarh M
UNIV SAARLAND,GEBAUDE 44,W-6650 HOMBURG,GERMANY. UNIV SAARLAND,INST HUMAN GENET,W-6650 HOMBURG,GERMANY.
Int J Oncol. 1992 Oct;1(5):571-9. doi: 10.3892/ijo.1.5.571.
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.
已知从转化细胞中免疫纯化的突变小鼠p53与一种蛋白激酶紧密相关，该蛋白激酶在体外激酶反应中使p53磷酸化。来自未转化细胞系的野生型p53与蛋白激酶不相关，而来自转化细胞系的免疫纯化野生型p53与一种使p53磷酸化的蛋白激酶紧密相关。为了在相同的细胞环境中比较野生型和突变型p53，将两种形式的p53都克隆到杆状病毒表达系统和体外转录/翻译载体中，并在这两个系统中表达两种p53蛋白。来自杆状病毒感染昆虫细胞的野生型和突变型p53与一种使p53磷酸化的蛋白激酶紧密相关。相比之下，来自体外转录/翻译反应的免疫纯化野生型和突变型p53与蛋白激酶不相关，但可被添加的酪蛋白激酶II磷酸化。因此，在本文中我们证明p53与蛋白激酶的结合以及p53的体外磷酸化似乎取决于周围的细胞环境。
