Critical Interactions of APOBEC3s: Molecular Approaches to Novel HIV Therapies

描述（由申请人提供）：APOBEC3 (A3)-Vif相互作用决定HIV是否“存活”或“死亡”。在正常感染中，HIV使用其辅助蛋白Vif来中和细胞逆转录病毒限制因子A3G和A3F。相反，在缺乏Vif的情况下，这些A3蛋白能够有效地抑制HIV的传染性。因此，A3-Vif相互作用已成为开发新型治疗干预措施的主要目标。然而，由于对这些A3蛋白或HIV Vif的结构、生物物理和生化研究非常少，目前阻碍治疗发展的一个因素是巨大的知识缺口。为了填补这一空白，我们组建了一个真正的多学科项目，结合了五个实验室的优势，每个实验室在分子病毒学、核磁共振波谱、x射线晶体学、AFM力谱和生物化学方面都有互补的专业知识。我们的项目是为了实现以下广泛的，高影响力的目标：(i)阐明全长A3G结构，并全面了解该蛋白在HIV限制期间如何寡聚；（ii）定义A3G如何结合单链DNA并催化胞苷到尿苷脱胺；（iii）解剖A3G和A3F的Vif相互作用表面，以充分了解关键的相似性和差异性。我们还将使用新的A3G抑制剂和小肽作为分子探针来解剖DNA脱氨机制的各个阶段。每个研究者都将运用他/她的专业知识来实现这些目标，我们的团队将努力构建A3F和A3G如何介导HIV-1限制以及Vif如何抵消这些多方面和有效的先天免疫防御的“大局”。总的来说，这个项目将提供前所未有的原子、生物物理、生化和分子信息。我们预计这些知识将有助于加速利用A3/Vif轴的新型艾滋病毒/艾滋病治疗方法的开发和实施。

DESCRIPTION (provided by applicant): The APOBEC3 (A3)-Vif interaction dictates whether HIV 'lives' or 'dies'. In a normal infection, HIV uses its auxiliary protein Vif to neutralize the cellular retroviral restriction factors A3G and A3F. Conversely, in the absence of Vif, these A3 proteins are able to potently inhibit HIV infectivity. The A3-Vif interaction has therefore become a prime target for the development of novel therapeutic interventions. However, a current impediment to therapeutic development is a vast knowledge gap owing to the fact that there are precious few structural, biophysical and biochemical studies on these A3 proteins or HIV Vif. To fill this gap, we have assembled a truly multidisciplinary Program Project that combines the strengths of five laboratories, each with complementary sets of expertise in molecular virology, NMR spectroscopy, X-ray crystallography, AFM force spectroscopy and biochemistry. Our projects are assembled to achieve the following broad, high-impact objectives: (i) elucidate the full-length A3G structure and gain a comprehensive understanding for how this protein oligomerizes during HIV restriction, (ii) define how A3G binds single-strand DNA and catalyzes cytidine to uridine deamination, and (iii) dissect the Vif interaction surfaces of A3G and A3F to fully understand critical similarities and differences. We will also use novel A3G inhibitors and small peptides as molecular probes to dissect stages of the DNA deamination mechanism. Each investigator will apply his/her specific expertise to each of these aims and our team will work toward building-up the 'big picture' for how A3F and A3G mediate HIV-1 restriction and how Vif counteracts these multifaceted and potent innate immune defenses. Overall, this Program Project will provide unprecedented atomic, biophysical, biochemical, and molecular information. We anticipate that this knowledge will help accelerate the development and implementation of novel HIV/AIDS therapeutics that work by leveraging the A3/Vif axis.