DNA BASE EXCISION REPAIR IN PLASMODIUM FALCIPARUM

描述：(申请人提供)：DNA复制和修复，过程 对细胞增殖和基因组的维持是必不可少的 正直，在寄生虫学中很大程度上没有被研究过。复制和 恶性疟原虫DNA修复的控制可能有许多 与哺乳动物细胞的差异。作为滋养体的快速复制 成熟为裂殖体和微配子的三轮复制 在10分钟内完成这两项任务都是不寻常的。出于这个原因，一个 基本了解寄生虫的这些过程是一个重要的目标。 我们的突破性调查显示，恶性疟原虫(PJ)已经 DNA修复能力，尿嘧啶的清除和修复 Dna中的基本位置是由长斑块碱基切除修复(BER)所独有的。 途径，这与哺乳动物细胞有显著的不同。重要 在BER途径的酶学研究中，P. 恶性疟原虫和哺乳动物细胞已经建立。短期目标是 这项建议是为了定义疟原虫中BER的基本反应 恶性疟原虫。寄生虫BER途径中的基本蛋白质是 这些酶的鉴定和在细菌中的过度表达将有助于 它们的生化特征。这些酶包括PF AP内切酶， PF瓣核酸内切酶(PF FEN-1)和PF DNA连接酶。这些酶的表达 是我们重建整个寄生虫误码率途径的计划的一部分 研究每种关键酶对 长补丁修复工艺。重新构建的误码率系统将提供未来的研究 各种蛋白质-蛋白质相互作用、机制、缔合和 BER受控情况下的生化反应。的最终目标是 这些研究是为了鉴定疟原虫切除修复基因，确定 它们的生物和生化功能，并评估它们在维持 寄生虫基因组。完成本项目中的拟议目标将 提供有关被忽视的寄生虫生物学领域的重要新信息， 也可能是利用P。 恶性疟原虫和哺乳动物细胞将开发抗疟疾的新策略 心理治疗。

DESCRIPTION: (provided by the applicant): DNA replication and repair, processes that are essential for cellular proliferation and the maintenance of genome integrity, have gone largely unexplored in parasitology. The replication and control of DNA repair in Plasmodium falciparum are likely to have a number of differences from the mammalian cell. The rapid replication as trophozoites mature into schizonts and the three rounds of replication that microgametes accomplish in 10 minutes at exflagellation are both unusual. For this reason, a basic understanding of these processes in the parasite is an important goal. Our groundbreaking investigations revealed that Plasmodium falciparum (Pj) has DNA repair capabilities, and that the removal of uracil and the repair of abasic sites in DNA are exclusively by a long-patch base excision repair (BER) pathway, which is remarkably different from mammalian cells. Important quantitative differences between the enzymology of the BER pathway in P. falciparum and mammalian cells have been established. The short-term goal of this proposal is to define the fundamental reaction of BER in Plasmodium falciparum. The essential proteins in the parasite BER pathway have been identified and the over expression of the enzymes in bacteria will facilitate their biochemical characterization. These enzymes include Pf AP endonuclease, Pf flap endonuclease (Pf FEN-1) and Pf DNA ligase. Expression of these enzymes is part of our plan to reconstitute the entire parasite BER pathway for studying the individual contributions of each of the key enzymes to the long-patch repair process. A reconstituted BER system will afford future study of the various protein-protein interactions, mechanisms, associations and biochemical reactions under controlled situations of BER. The ultimate goal of these studies is to identify the Plasmodium excision repair genes, determine their biological and biochemical function and assess their role in maintaining the parasite genome. Completion of the proposed aims in this project will provide important, new information about a neglected area of parasite biology, and possibly the opportunity to exploit differences in DNA repair between P. falciparum and mammalian cells to develop new strategies for antimalarial therapy.