CHARACTERIZATION OF HUMAN ORIGIN RECOGNITION COMPLEX

DNA复制是细胞分裂的重要前奏， 增殖该过程是细胞周期调控的重要目标 因为DNA的准确复制对生存能力至关重要， 在正确的时间。这个过程的失败通常会导致 基因组内的突变。此外，基因组稳定性可能会受到损害， 如果DNA完全复制，或者如果存在局部重新启动， 复制，因为DNA的异常分配会发生在 分裂。这些不规则现象被发现与 不同类型的癌症。这些违规行为 与不同类型的癌症有关。因此，阐明 DNA复制调节和机制将有助于 研发新药来对抗这些疾病目前， DNA复制或识别它们的蛋白质尚未被确定 并详细描述了人类和其他哺乳动物的特征。开始 为了区分这些来源，我们首先建议从人类细胞中纯化 从人体细胞中纯化一组蛋白质，即原始识别复合物 (ORC)，这被认为是绑定到起源。然后，我们打算确定 靶向人ORC的结合位点，并表征 最后，我们希望克隆剩下的亚基 人类有机体这些研究是迈向 人类复制起点的详细特征。更 重要的是，这项建议是制定一项 人无细胞系统，其能够启动DNA合成， 特定的人类起源，这将是至关重要的实验设计， 阐明DNA复制起始的确切机制。

DNA replication is an essential prelude to cell division and proliferation. The process is an important target of cell cycle control because it is critical for viability that the DNA is copied accurately and precisely at the correct time. Failure in this process generally leads to mutations within the genome. Moreover, genome stability may be compromised if DNA is replicated completely or if there is local re-initiation of replication because abnormal partitioning of the DNA would occur during mitosis. These kinds of irregularities have been found to be associated with different types of cancer. These kinds of irregularities have been found to be associated with different types of cancer. Thus, elucidating the regulation and mechanism of DNA replication would be useful for designing newer drugs to combat these diseases. At present, the origins of DNA replication or proteins that recognize them have not been identified and characterized in great detail in humans and other mammalians. To begin to distinguish these origins, we first propose to purify from human cells purify from human cells a set of proteins, the origin recognition complex (ORC), that is presumed to bind to origins. We then intend to identify the target binding sites of human ORC and characterize the specificity of the protein-DNA interactions, Lastly, we wish to clone the remaining subunits of human ORC. These studies are an important first step towards the detailed characterization of human origins of replication. More significantly, this proposal is essential groundwork for developing a human cell-free system that is capable of initiating DNA synthesis from a specific human origin, which will be crucial for experiments designed to elucidate the precise mechanism of initiation of DNA replication.