HIV-1 assembly and release

描述(由申请人提供)： HIV-1颗粒的组装和释放是相当复杂的，因为许多病毒和细胞RNA和蛋白质参与其中，虽然关于这一过程已经了解了很多，但仍有许多有待发现。Gag蛋白是组装和释放HIV-1和所有其他逆转录病毒颗粒的核心。Gag蛋白的一个关键功能是病毒基因组RNA(GRNA)的招募和包装，这将是TIS提案的重点之一。反过来，随着组装的进行，gRNA可能有助于推动额外的Gag分子招募到病毒粒子中。然而，RNA在多大程度上参与细胞内的颗粒组装，以及随着组装的启动和完成，Gag：RNA的相互作用如何变化仍有待确定。在特定目标1中提出的实验将是第一个精确确定HIV-1 Gag和gRNA在细胞中如何相互作用的实验。这些研究可以确定Gag蛋白和gRNA以及gRNA和抗病毒胞苷脱氨酶之间的第一次和随后的相互作用。在组装之后，HIV-1颗粒离开感染细胞的表面，在邻近或远端的未感染细胞中定居。在之前的资助期间，我们发现了一种由干扰素诱导的膜蛋白，称为Tetherin，它是一种宿主防御分子，可以抑制HIV-1颗粒的释放。我们的工作已经证明，Tetherin直接作用于细胞表面，将新生的病毒粒子保留在细胞表面，但有关Tetherin如何发挥作用以及t在防止病毒感染在培养细胞和体内传播中所起作用的关键机制细节仍有待确定。在具体目标2中，我们将进行一系列体外和体内实验来解决这些关键问题。

DESCRIPTION (provided by applicant): The assembly and release of HIV-1 particles is quite complex, in that a number of viral and cellular RNAs and proteins participate, and while much has been learned about this process, much remains to be discovered. The Gag protein is central to the assembly and release of HIV-1 and all other retrovirus particles. A key function of the Gag protein that will be one focus of tis proposal is the recruitment and packaging of viral genomic RNA (gRNA). Reciprocally, gRNA may help to drive the recruitment of additional Gag molecules into a virion as assembly progresses. However, the full extent to which RNA participates in particle assembly in cells, and how Gag:RNA interactions change as assembly is initiated and completed remain to be defined. The experiments proposed in specific aim 1 will be the first to determine precisely how HIV-1 Gag and gRNA interact in cells. These studies could identify the very first as well as subsequent interactions between Gag protein and gRNA as well as between gRNA and antiviral cytidine deaminases. Following assembly, HIV-1 particles depart from the surface of the infected cell, to colonize neighboring or distal uninfected cells. During the previous funding period, we identified an IFN-induced membrane protein, termed tetherin, as a host defense molecule that inhibits HIV-1 particle release. Our work has demonstrated that tetherin acts directly, to retain nascent virions on the cell surface, but key mechanistic details of how tetherin functions, and what role t plays in preventing the dissemination of viral infection in cultured cells and in vivo remain to b determined. In specific aim 2, we will perform a series of in vitro and in vivo experiments to address these key questions.