Role of HIV-1 Integrase in the Late Stage of Viral Replication

描述（由申请人提供）：HIV-1整合酶（IN）对病毒复制至关重要，因此是重要的治疗靶点。在病毒复制的早期阶段，HIV-1 IN的四聚体催化逆转录的病毒DNA整合到宿主基因组中。IN在病毒DNA存在下的有序多聚化对于IN催化的多聚化是至关重要的。 活动细胞辅因子LEDGF/p75与预组装的IN-病毒DNA复合物结合，并将核蛋白复合物与活性基因结合，从而确保有效整合。变构整合酶抑制剂（ALLINI）是一类新型的整合酶抑制剂，其在IN二聚体界面的LEDGF/p75结合位点处结合，并且能够触发异常IN多聚化。此外，在ALLINI存在下产生的HIV-1病毒体显示病毒体核心的异常形态，并且对于随后的逆转录和在靶细胞中的整合是有缺陷的。有趣的是，这些表型与某些IN突变体相似，这些IN突变体被称为II类突变体。总的来说，ALLINI和选择IN II类突变体的研究表明，HIV-1 IN在晚期HIV-1复制中起关键作用。然而，其内在机制尚不清楚。本申请将测试以下假设：有序IN多聚化对于其在后期病毒复制期间与病毒RNA的相互作用是重要的。因此，我们提出以下两个具体目标。目的1探讨HIV-1IN与RNA相互作用在病毒复制后期形成功能性核糖核蛋白复合物中的意义。目的2将表征影响IN多聚化和/或IN-LEDGF/p75结合的IN突变体。从这些研究中出现的机制和结构细节将为药物发现工作提供信息，以开发改进的ALLINI用于其临床应用。

DESCRIPTION (provided by applicant): HIV-1 integrase (IN) is essential for viral replication and thus is an important therapeutic target. During the early stages of viral replication, a tetramer of HIV-1 IN catalyzes integration of reverse transcribed viral DNA into the host genome. The ordered multimerization of IN in the presence of viral DNA is critical for IN catalytic activity. Cellular cofactor LEDGF/p75 binds to the pre-assembled IN- viral DNA complex and tethers the nucleoprotein complex to active genes, thus ensuring effective integration. Allosteric integrase inhibitors (ALLINIs) are a novel class of integrase inhibitors that bind at the LEDGF/p75 binding site at the IN dimer interface and are capable of triggering aberrant IN multimerization. In addition, HIV-1 virions produced in the presence of ALLINIs display abnormal morphology of the virion cores and are defective for subsequent reverse transcription and integration in target cells. Interestingly, these phenotypes are similar to certain IN mutants, which have been termed class II mutants. Collectively, the studies with ALLINIs and select IN class II mutants suggest that HIV-1 IN plays a key role during late stage HIV-1 replication. However, the underlying mechanism is not clear. The present application will test the following hypothesis: ordered IN multimerization is important for its interaction with viral RNA during the late stage viral replication. Therefore, we propose the following two specific aims. Aim 1 will explore the significance of HIV-1 IN interactions with RNA for formation of the functional ribonuleoprotein complexes during the late stage viral replication. Aim 2 will characterize IN mutants that affect IN multimerization and/or IN- LEDGF/p75 binding. Mechanistic and structural details that will emerge from these studies will inform drug discovery efforts to develop improved ALLINIs for their clinical application.