The transcription factor of cyclin-dependent kinase 2 (cdk2) gene.

点击翻译按钮获取中文摘要

cdk2 is a protein kinase and its activity changes during the cell cycle. It is postulated that this change of activity follows the change of transcription rate of the gene and post-translational modification. We found the mRNA of cdk2 begun to increase at G1/S and reached to the largest level at S-phase then declined thereafter. We showed that the transcription amount of cdk2 changed during the cell cycle. To determine the DNA region which involved in the cell-cycle dependent regulation of the gene, mouse cdk2 gene was cloned. And fragments from+68bp to various sites of 5'upstream region were subcloned, and luciferase reporters were prepared. These reporters were transfected into CHO cells, and stable transformants were obtained. After synchronization of the cell cycle of these stable transformants, the activities of luciferase were assayd. We showed that the region from +68bp to- 419bp was required for cell-cycle dependent expression of luciferase. We also studied the post-translational modification of cdk2. It is suggested that the activity of cdk family proteins changes with their phospyorylation and dephosphorylation, however, the kinase (s) and phosphatase (s) are not well understood. wee1 is postulated as the one of such kinases, and we cloned cDNA of mouse wee1. This clone consisted with 2258bp and its open reading frame corresponds to a 646 amino acid residues. This mouse wee1 clone was inserted into vaculovirus transfer vector, and studied on phosphorylation. The results obtained were 1) mouse wee1 was inactivated by a phosphorylation of an amino acid residue of N-terminal region of the protein, 2) mouse wee1 phosphorylated the cdc2 kinase. We study if mouse wee1 phosphorylates cdk2, as well.