Structural Virology of Tripartite Motif Proteins

项目摘要/摘要 病毒成分，如HIV-1衣壳和病毒编码的RNA，可以触发强大的天然防御 当被宿主细胞感知时的机制。三部分基序(TRIM)蛋白是泛素E3连接酶 在感知这些病毒成分方面发挥重要作用：TRIM5a蛋白被建立来识别 即将到来的HIV-1衣壳和逆转录病毒，以及TRIM25在感知方面具有重要但仍然神秘的作用 病毒核糖核酸。R01项目的主要目标是阐明这些传感器的分子机制。 在目标1中，我们建议：(1)阐明TRIM5a如何识别HIV-1和逆转录病毒的分子细节 通过前所未有的点阵到点阵模式识别机制，(2)了解如何 TRIM5a/衣壳复合体中多种不同的蛋白质-蛋白质相互作用共同决定限制 以及(3)发展新的生化重组方法来概括和分析TRIM5a- 体外介导性限制性内切酶。在目标2中，我们建议：(1)阐明TRIM25如何 识别病毒RNA，以及(2)了解这种活动如何与泛素化相协调，以使 对病毒基因组和病毒编码的信使RNA的识别。来自这些研究的见解可能会 提出抗击HIV-1和其他病毒感染的新方法。

Project Summary/Abstract Virus components such as the HIV-1 capsid and virus-encoded RNA can trigger powerful innate defense mechanisms when sensed by the host cell. Tripartite motif (TRIM) proteins are ubiquitin E3 ligases that perform important roles in sensing these virus components: TRIM5a proteins are established to recognize the incoming capsids of HIV-1 and retroviruses, and TRIM25 has an important but still enigmatic role in sensing viral RNA. The principal goals of this R01 project are to elucidate the molecular mechanisms of these sensors. In Aim 1, we propose to: (1) elucidate the molecular details of how TRIM5a recognizes HIV-1 and retroviral capsids through an unprecedented mechanism of lattice-to-lattice pattern recognition, (2) understand how multiple different protein-protein interactions in the TRIM5a/capsid complex cooperate to determine restriction susceptibility, and (3) develop novel biochemical reconstitution methods to recapitulate and analyze TRIM5a- mediated restriction in vitro. In Aim 2, we propose to: (1) elucidate the molecular details of how TRIM25 recognizes viral RNA, and (2) understand how this activity is coordinated with ubiquitination in order to enable recognition of both viral genomes and virally-encoded messenger RNA. Insights from these studies are likely to suggest novel ways to fight HIV-1 and other viral infections.