ROLE OF PFHO-1 IN P. FALCIPARUM INTRAERYTHROCYTIC DEVELOPMENT

摘要 控制恶性疟原虫红细胞内生长和控制的探讨 发展还处于初级阶段。了解寄生虫的信号和效应器 进展将增强我们对这种寄生虫如何在其宿主中生存的知识 细胞，并将发现新的化疗靶点。PfHO-1是一种亚铁血红素 功能未知的加氧酶样蛋白在红细胞内表达 疟疾寄生虫。我们已经发现PfHO-1具有一种对卟啉反应的DNA- 结合活性，并优先与参与 蛋白质合成。我们的假设是PfHO-1对血红素的积累有反应 防止血红蛋白降解，对红细胞内恶性疟原虫至关重要 发展。这里提出的这项研究的目标是检验这一假说。我们 将评估PfHO-1对细胞内卟啉扰动的反应 在红细胞内恶性疟原虫和大肠杆菌报告系统中的水平。我们会 一种新的双阳性选择基因敲除抑制PfHO-1的作用 方法和通过条件表达的卟啉无反应的版本 蛋白质。这些研究将使我们能够确定PfHO-1是否在 在细胞卟啉水平检测中的重要作用和参与关键 细胞动态平衡的各个方面。拟议中的实验也将发展。 卟啉操作和有害物质筛选的新技术 反向基因工程寄生虫的表型。

Abstract Exploration of the control of Plasmodium falciparum intraerythrocytic growth and development is in its infancy. Understanding the signals and effectors of parasite progression will enhance our knowledge of how this parasite survives in its host cell and will uncover new targets for chemotherapy. PfHO-1 is a heme oxygenase-like protein of unknown function expressed in intraerythrocytic malaria parasites. We have found that PfHO-1 has a porphyrin-responsive DNA- binding activity and associates preferentially with genes that are involved in protein synthesis. Our hypothesis is that PfHO-1 responds to heme accumulation from hemoglobin degradation and is crucial for intra-erythrocytic P. falciparum development. The goal of the study proposed here is to test this hypothesis. We will assess the response of PfHO-1 to perturbation of intracellular porphyrin levels in intraerythrocytic P. falciparum and in an E. coli reporter system. We will impair PfHO-1 action by a new double-positive selection gene knockout approach and by conditional expression of a porphyrin-unresponsive version of the protein. These studies will allow us to establish whether PfHO-1 plays an important role in sensing cellular porphyrin levels and participating in critical aspects of cellular homeostasis. The proposed experiments will also develop new technologies for porphyrin manipulation and for selection of deleterious phenotypes in reverse genetically engineered parasites.