Initiation of SV40 DNA Replication and Its Regulation

SV40 DNA复制的启动及其调控

基本信息

批准号：
6844339
负责人：
PETER Augustus BULLOCK
金额：
$ 30.91万
依托单位：
TUFTS UNIVERSITY BOSTON
依托单位国家：
美国
项目类别：
财政年份：
1992
资助国家：
美国
起止时间：
1992-01-01 至 2006-01-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/6844339
关键词：
DNA replication DNA replication origin nucleic acid sequence simian virus 40 tissue /cell culture virus genetics virus protein virus replication

项目摘要

DESCRIPTION (provided by applicant): Many DNA tumor viruses encode "initiators" proteins that site specifically bind to viral origins of DNA replication. Upon binding to their respective origins, the initiators assemble into DNA helicases that are capable of melting duplex DNA. Initiators also recruit cellular proteins required for synthesis of nascent DNA. We are attempting to understand these processes by characterizing in depth an initiator encoded by Simian Virus 40, termed T-antigen (T-ag). Using the Simian Virus 40 system and simple band shift experiments, a fundamental question in biology will be addressed: "how does the cell cycle machinery control the assembly of initiators on viral origins of replication?" Recent experiments with T-ag derived peptides, whose ability to bind to DNA is regulated by phosphorylation of Thr 124, are providing significant insights into this process. Experiments are proposed to determine if similar mechanisms are operating in the context of T-ag. Related aspects of T-ag assembly and regulation will be considered, such as locating a site on T-ag whose interactions with the flanking sequences in the core origin is necessary for T-ag binding. Collectively, these studies will provide information that may allow us to solve the mechanism of DNA unwinding. Once the SV40 origin is unwound, the pol alpha-primase complex initiates the synthesis of nascent DNA strands. Exactly what sequences constitute the initiation sites for the pol alpha-primase complex is the topic of an additional series of experiments. Given that many basic processes are conserved throughout evolution, we are confident that the information we obtain from these studies will be pertinent to the initiation of DNA replication at other viral origins of replication. Furthermore, they may help us to understand how the cell cycle machinery controls initiation events at cellular origins. Given that uncontrolled DNA replication is thought to be a component of many diseases, including cancer, it is very important to understand how DNA replication is initiated and how it is controlled.

描述（由申请人提供）：许多DNA肿瘤病毒编码“发起人” 该位点特异性结合DNA复制的病毒起源的蛋白质。之上与其各自起源的结合，启动器组装成DNA解旋酶能够熔化双链DNA的那些。发起人还招募蜂窝合成新生DNA所需的蛋白质。我们试图理解这些过程通过深入表征由Simian病毒编码的引发剂 40，称为T抗原（T-AG）。使用Simian病毒40系统和简单频段 Shift实验，将解决生物学的一个基本问题：“如何细胞周期机械是否控制病毒启动器的组装复制的起源？与DNA结合的能力受THR 124的磷酸化调节为此过程提供了重要的见解。提出了实验确定在T-AG的背景下进行类似机制。有关的将考虑T-AG组装和调节的各个方面，例如定位 T-ag上的站点，其与核心起源中侧翼序列的相互作用对于T-AG结合是必需的。这些研究共同提供可能使我们可以解决DNA解开机制的信息。一旦 SV40起源是解开的，Pol Alpha-primase复合物启动了合成新生的DNA链。确切的序列构成了启动位点对于Pol Alpha-primase综合体是另外一系列的主题实验。鉴于许多基本过程在整个过程中保存下来进化，我们相信我们从这些研究中获得的信息将与其他病毒起源的DNA复制启动有关复制。此外，它们可能会帮助我们了解细胞周期机械控制细胞起源的起始事件。鉴于不受控制的DNA复制被认为是许多疾病的组成部分，包括癌症，了解DNA复制是非常重要的启动及其如何控制。