Dissecting the role of ApiAP2 proteins in transcriptional regulation during Plasmodium falciparum development

尽管多年来人们一直认为疟原虫是疟疾的病原体， 缺乏序列特异性转录因子，我们实验室和其他人的工作现在已经 表明它们拥有有限数量的这种调节蛋白。顶复门AP 2 ApiAP 2蛋白，其起源类似于植物，现在被广泛认为是唯一的主要的蛋白质。 在疟原虫基因组中鉴定的DNA结合蛋白家族。我们的核心假设是， ApiAP 2蛋白家族的成员是整个发育过程中的主要调节因子。 疟疾寄生虫的整个生命周期。ApiAP 2蛋白在大小上高度可变，并且含有 从一个到三个AP 2 DNA结合结构域。我们测量了DNA结合 对疟原虫所有AP 2结构域的特异性，证明了广泛的DNA序列 特殊性通过确定这些DNA基序在全基因组范围内的出现，我们可以开始 预测一些ApiAP 2蛋白的功能作用。然而，详细的机制研究， 证实了这些预测是滞后的。这项建议旨在界定一个机构的职能作用， ApiAP 2蛋白的一个子集，与血液阶段发育的关键过程相关，包括 红细胞侵入、配子体发生和配子体定型的调节 分化和成熟。首先，我们将定义PfAP 2-G的转录调控网络 （PF3D7_1222600），我们已经证明它是性阶段的主要调节剂 承诺.我们还将研究另外两种与配子体相关的ApiAP 2蛋白， 发育（PF3D7_1317200，PF3D7_1408200），以确定其在配子体调节中的作用 分化接下来，我们提出表征PF3D7_1007700的作用，我们预测它是一种 红细胞侵入的调节剂。由于PF3D7_1007700含有三个AP 2 DNA结合结构域， 每一个都有独特的DNA结合特异性，这将使我们能够剖析单个AP 2的贡献， 这些结构域与该蛋白质的功能（以及通过类推的其他ApiAP 2蛋白质）相关。最后，我们有 在ApiAP 2蛋白中发现了一个新的保守结构域，并将开始努力表征 该结构域的结构和功能，以及试图在这些结构域中定义反式激活区域， proteins.为了实现我们的目标，我们将结合使用已建立的技术，包括 寄生虫的遗传操纵、生物化学和全基因组方法。了解 恶性疟原虫转录调控过程的分子机制将提供关键的 研究寄生虫发展所需的工具，也提出了新的治疗目标， 旨在阻断寄生虫成熟的干预策略。ApiAP 2蛋白严格存在于 因此，顶复门寄生虫是新的抗疟疗法的有吸引力的候选者。

Although for many years it was thought that Plasmodium parasites, the causative agents of malaria, were devoid of sequence-specific transcription factors, work from our lab and others has now demonstrated that they possess a limited number of such regulatory proteins. The apicomplexan AP2 (ApiAP2) proteins, which are plant-like in their origin, are now widely considered to be the single major family of DNA binding proteins identified in the Plasmodium genome. Our central hypothesis is that members of the ApiAP2 protein family are the major regulators of development throughout the complete lifecycle of the malaria parasite. ApiAP2 proteins are highly variable in size and contain anywhere from one to three AP2 DNA binding domains. We have measured the DNA binding specificities for all AP2 domains from Plasmodium demonstrating a broad array of DNA sequence specificities. By determining the genome-wide occurrence of these DNA motifs, we can begin to predict the functional roles for some ApiAP2 proteins. However, detailed mechanistic studies to confirm these predictions have been lagging. This proposal seeks to define the functional role for a subset of ApiAP2 proteins associated with processes critical to blood-stage development including the regulation of red blood cell invasion, commitment to gametocytogenesis and gametocyte differentiation and maturation. First, we will define the transcriptional regulatory network of PfAP2-G (PF3D7_1222600), which we have demonstrated to be a master regulator of sexual stage commitment. We will also investigate two additional ApiAP2 proteins implicated in gametocyte development (PF3D7_1317200, PF3D7_1408200) to define their role in the regulation of gametocyte differentiation. We next propose to characterize the role of PF3D7_1007700, which we predict to be a regulator of red blood cell invasion. Since PF3D7_1007700 contains three AP2 DNA binding domains, each with unique DNA binding specificity, this will allow us to dissect the contribution of individual AP2 domains to the function of this protein (and other ApiAP2 proteins by analogy). Lastly, we have identified a new conserved domain in ApiAP2 proteins and will initiate efforts to characterize the structure and function of this domain as well as seeking to define transactivation regions within these proteins. To accomplish our goals, we will use a combination of established techniques, including genetic manipulation of the parasite, biochemistry, and genome-wide approaches. Understanding the molecular mechanisms of transcriptional regulatory processes in P. falciparum will provide critically needed tools for studying parasite development, and also presents therapeutic targets for new intervention strategies aimed at blocking parasite maturation. ApiAP2 proteins are strictly found in Apicomplexan parasites and therefore are attractive candidates for new antimalarial therapies.