The control of the initiation step of DNA replication by proteinkinase Dbf4/Cdc7 Regulation des murinen "origin recognition complex (ORC)" durch Cyclin-Cdk-Komplexe

我们特别的长期目标是阐明在G1/S相变中控制DNA复制开始的分子机制。我们正在寻求支持的项目将集中在蛋白激酶复合体DBF4/CDC7在细胞周期从G1期向S期转变过程中所起的特殊作用及其对有丝分裂信号转导级联的依赖。具体地说，我们将研究以下方面：(I)Dbf4p和CDc7p之间的相互作用对激酶活性的影响和相互作用结构域的结构分析；(Ii)Dbf4/CDc7p的磷酸化位点及其点突变的分析；(Iii)细胞周期蛋白/CDKs和自磷酸化对Dbf4/cdc7p磷酸化的功能影响；(Iv)Dbf4/CDc7p激酶活性靶标的鉴定；(V)用于分析Dbf4/CDC7在细胞增殖和分化中功能的条件性基因敲除小鼠的建立。我们期望这些研究将有助于对Dbf4/CDC7参与启动DNA复制和细胞周期控制的机制有一个全面的了解。

Our particular long-term aim is the elucidation of the molecular mechanisms governing the onset of DNA replication at the G1/S phase transition. The project we are seeking support for will be focussed on the particular role played by the protein kinase complex Dbf4/Cdc7 during the transition from the G1 to the S phase of the cell cycle and its dependence on the mitogenic signal transduction cascade. Specifically, we will investigate the following aspects: (i) effects of interactions between Dbf4p and Cdc7p on kinase activity and structural analysis of interacting domains, (ii) analysis of phosphorylation sites in Dbf4/Cdc7p and their point mutation (iii) functional effects of phosphorylation of Dbf4/cdc7p by cyclin/Cdks and by autophosphorylation, (iv) characterization of targets of Dbf4/Cdc7p kinase activity, (v) generation of conditional knock-out mice for the analysis of functions of Dbf4/Cdc7 in cell proliferation and differentiation. We expect that these studies will lead to a general understanding of the mechanism by which Dbf4/Cdc7 contributes to initiation of DNA replication and cell cycle control.