Structure and function relationships regulating SAMHD1's dual enzymatic activities

 描述（由申请人提供）：SAMHD 1是一种脱氧核糖核苷三磷酸（dNTP）三磷酸水解酶。它是一种宿主细胞限制因子，在防御人类免疫缺陷病毒1（HIV-1）感染中发挥关键作用。SAMHD 1降低dNTP的细胞浓度，使得有效的逆转录被禁止。有趣的是，SAMHD 1还具有核酸酶活性，这对于其HIV-1限制是必需的。了解这两个重要的生物学活动及其调节的分子和结构基础将提供重要的洞察HIV限制机制。为此我们 提出以下目标：在目标1中，我们将确定三磷酸核苷对SAMHD 1 dNTR酶活性的结构基础和分子机制。在目标2中，将研究结构域内和结构域间相互作用的结构-功能关系。在目标3中，e将表征SAMHD 1的核酸酶活性及其结构决定簇。这项工作的结果将为设计新的治疗方法来防治艾滋病提供途径。

 DESCRIPTION (provided by applicant): SAMHD1 is a deoxyribonucleoside triphosphate (dNTP) triphosphohydrolase. It is a host cell restriction factor that plays critical roles in the defense against human immunodeficiency virus 1 (HIV-1) infection. SAMHD1 lowers the cellular concentrations of dNTP such that effective reverse transcription is prohibited. Interestingly, SAMHD1 also possesses nuclease activity, shown to be essential for its HIV-1 restriction. Understanding the molecular and structural basis of these two important biological activities and their regulation will provide important insight into mechanisms of HIV restriction. To this end, we propose the following Aims: In Aim 1, we will determine the structural basis and molecular mechanisms of SAMHD1 dNTPase activity by nucleoside triphosphates. In Aim 2, the structure-function relationship of the intra- and inter- domain interactions will be investigated. In Aim 3, e will characterize the nuclease activity of SAMHD1 and its structural determinants. Results from this work will provide avenues for designing new therapeutic approaches to fight AIDS.