DNA BASE EXCISION REPAIR IN PLASMODIUM FALCIPARUM

描述：（由申请人提供）：DNA复制和修复，过程 对细胞增殖和基因组的维持至关重要 完整性，在寄生虫学中基本上没有被探索过。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 成熟为小配子和小配子的三轮复制 在10分钟内完成抽苔都是不寻常的。因此，A 对寄生虫中这些过程的基本了解是一个重要的目标。 我们的突破性研究表明，恶性疟原虫（Pj） DNA修复能力，尿嘧啶的去除和DNA的修复， DNA中的无碱基位点完全通过长补丁碱基切除修复（BER）来实现 这是一种与哺乳动物细胞显著不同的途径。重要 BER途径的酶学在P. 恶性疟原虫和哺乳动物细胞已经建立。的短期目标 该建议旨在确定BER在疟原虫中的基本反应 恶性疟原虫。寄生虫BER途径中的必需蛋白质已被 细菌中酶的过度表达将有助于 他们的生化特征。这些酶包括Pf AP内切核酸酶， Pf瓣状核酸内切酶（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BER通路计划的一部分， 研究每种关键酶对蛋白质合成的贡献， 长斑修复过程。一个重构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，协会和 生化反应的BER控制情况下。的最终目标 这些研究是为了确定疟原虫切除修复基因， 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的拟议目标将 提供了重要的，新的信息，关于寄生虫生物学的一个被忽视的领域， 并可能有机会利用P. 恶性疟原虫和哺乳动物细胞开发抗疟新策略 疗法

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.