The Mammalian Cell Cycle Control and Tumor Genesis

描述（由申请人提供）：这是CA 65572的第二次竞争性更新，该研究旨在了解哺乳动物细胞周期控制和肿瘤发生的长期目标。回顾过去10年的历程，我们高兴地看到我们对该领域作出的贡献，更值得注意的是，在该领域工作的其他人共同取得了进展。我们自己的研究重点已经从1993年确定新发现的第一个CDK抑制剂p21的功能和调节，发展到第二个资助期发现和研究Arf-Mdm 2-p53通路。本申请中提出的研究将集中于确定p53的细胞质控制，这是一个正在成为p53调节和肿瘤抑制中的关键调节步骤的领域。导致这一建议是我们和其他人最近的三个发现：（i）在调节p53中通过多个应激检查点途径广泛利用核输出;（ii）发现ROC 1和ROC 2作为cullin家族E3泛素连接酶的催化亚基，以及（iii）两种ROC依赖性连接酶PARC和CUL 7与p53结合并定位于细胞质中。 本论文的主要目的是：（目的I）PARC与p53相互作用的功能结果，（目的II）PARC和CUL 7的功能机制，（目的III）DOC结构域在PARC和CUL 7中的功能，（目的IV）PARC RBR结构域的功能。该提案结合了我们在四个领域的优势和成功：具有靶向突变的小鼠的遗传和肿瘤分析;泛素连接酶的生化表征; p53输出和p53检查点途径的细胞研究，以及基于IP-质谱的蛋白质复合物表征。我们期望这些全面和多学科的研究将导致更好地了解p53的细胞质控制，泛素途径的功能和机制以及肿瘤抑制的过程。

DESCRIPTION (provided by applicant): This is the second competing renewal of CA65572, an investigation that is aimed at the long-term goal of understanding mammalian cell cycle control and tumorigenesis. Looking back at the journey of the last 10 years, we are pleased to see the contribution we made to the field and, more remarkably, the advancement achieved collectively by others working in this field. The focus of our own research has moved forward from determining the function and regulation of the newly discovered first CDK inhibitor, p21 in 1993, to the discovery and study of the Arf-Mdm2-p53 pathway during the second funding period. The research proposed in this application will focus on determining the cytoplasmic control of p53, an area that is emerging as a critical regulatory step in p53 regulation and tumor suppression. Leading to this proposal are three findings we and others made recently: (i) broad utilization of nuclear export by multiple stress checkpoint pathways in regulating p53; (ii) the discovery of ROC1 and ROC2 as the catalytic subunit of cullin family E3 ubiquitin ligases, and (iii) two ROC-dependent ligases, PARC and CUL7, bind to p53 and localize in the cytoplasm. Four specific aims are proposed to determine: (Aim I) The functional consequence of PARC-p53 interaction, (Aim II) The mechanisms of PARC and CUL7 function, (Aim HI) The function of DOC domain in PARC and CUL7, and (Aim IV) The function of RBR domain of PARC. This proposal combines our strength and success in four areas: genetic and tumor analysis in mouse with targeted mutations; biochemical characterization of ubiquitin ligases; cellular studies of p53 export and p53 checkpoint pathways, and IP-Mass Spec-based protein complex characterization. We anticipate that these comprehensive and multi-disciplinary studies will lead to a better understanding of cytoplasmic control of p53, the function and mechanism of the ubiquitin pathway and the process of tumor suppression.