内质网形态相关蛋白atlastin-1对HIV-1膜融合及细胞运输调控的分子机制

HIV/AIDS has seriously damaged worldwide human public health and has incurred enomous economic costs globally. This public health problem has attracted great attention of the governments and scientists all over the world. It is still unclear that the molecular mechanisms in HIV replication as well as the interaction between HIV and its cellular factors within the host, such as endomembrane system and cytoskeleton. As the sites of virus assembly, both of endomembrane system and cytoskeleton are involved in the replication cycles of HIV-1. Atlastin-1(ATL1), an endoplasmic reticulum morphology related protein, is found to be widely distributed in the endomembrane system, and it can interact with spastin, a kind of microtubule severing protein. Therefore, we will hypothesize that ATL1 may affect HIV-1 replication by means of endomembrane system and cytoskeleton. Our preliminary results showed that over-expression of ATL1 in HIV target cells TZM-bl could promote HIV-1 replication there as well as enhancing Env-mediated HIV-1 membrane fusion. Furthermore, it implicated that such an action of ATL1 was associated with unknown molecular mechanisms rather than GTPase activity originated from ATL1. Therefore molecular mechanisms in HIV membrane fusion and intracellular trafficking regulated by ATL1 need to be explored further. Thus we will design and make synthesis of inhibitory short peptides based on the molecular pathway of ATL1 acting on HIV-1 replication, and will analyze the effects of inhibitory peptides on HIV-1 replication. This study will enrich the mechanisms of HIV replication and provide strategy for developing new drugs of blocking HIV-1 replication.

艾滋病严重危害人类健康，造成巨大经济损失，引起社会极大关注。引起艾滋病的病原体HIV复制的分子机制及其与宿主细胞相互作用关系尚未完全清晰。作为病毒合成组装的场所- - 细胞的内膜系统和细胞骨架广泛参与HIV复制的多个环节。细胞内质网形态相关蛋白atlastin-1（ATL1）广泛分布于内膜系统，与微管切割蛋白spastin相互作用，影响细胞骨架结构。据此推测ATL1可能通过内膜系统和微管影响HIV-1复制。本室前期工作发现TZM-bl细胞中高表达ATL1可促进HIV-1复制，该效应不依赖ATL1的GTPase活性；进一步发现ATL1能够促进HIV Env介导的膜融合。本研究在此基础上，进一步明确ATL1影响HIV-1复制的具体环节，探索其分子机制；并以此为基础设计合成短肽，检测其抑制HIV-1复制的效果。本研究将丰富HIV-1细胞内复制机制研究，为研制阻断HIV-1复制药物提供新的靶点和思路。

艾滋病严重危害人类健康，造成巨大经济损失，引起社会极大关注。引起艾滋病的病原体HIV复制的分子机制及其与宿主细胞相互作用关系尚未完全清晰。作为病毒合成组装的场所——细胞的内膜系统和细胞骨架广泛参与HIV复制的多个环节。细胞内质网形态相关蛋白atlastin-1（ATL1）广泛分布于内膜系统。我们发现HIV-1的感染能够上调ATL1的mRNA的水平，而ATL1的过表达能够促进病毒的复制。进一步的机制探索发现，ATL1通过促进病毒Env在细胞的表达，从而促进细胞间的膜融合，进而促进病毒的细胞间传播。截短突变实验发现，ATL1的ATPase结构域是行使该功能的关键结构域。病毒复制动力学曲线表明，ATL1能够长效促进病毒复制。微管切割蛋白spastin能影响细胞骨架结构。本研究发现spastin的敲除，能够通过影响病毒gag在细胞内的浓度，抑制HIV-1的复制。进一步的研究发现，spastin主要通过影响Gag的溶酶体降解途径，影响Gag蛋白的细胞浓度；具体机制为，spastin通过与ESCRT途径的IST1蛋白相互作用来影响Gag的溶酶体降解途径。本研究丰富了HIV-1细胞内复制机制研究，为研制阻断HIV-1复制药物提供新的靶点和思路。