Critical Interactions of APOBEC3s: Molecular Approaches to Novel HIV Therapies

描述(由申请人提供)：APOBEC3(A3)-VIF相互作用决定艾滋病毒是‘活’还是‘死’。在正常感染中，HIV使用其辅助蛋白Vif中和细胞逆转录病毒限制因子A3G和A3F。相反，在没有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的治疗干预措施的主要目标。然而，目前治疗发展的一个障碍是巨大的知识差距，这是因为对这些A3蛋白或艾滋病毒VIF的结构、生物物理和生化研究非常少。为了填补这一空白，我们组建了一个真正的多学科计划项目，该项目结合了五个实验室的优势，每个实验室都拥有分子病毒学、核磁共振光谱、X射线结晶学、原子力光谱和生物化学方面的互补专业知识。我们的项目旨在实现以下广泛、高影响力的目标：(I)阐明A3G的全长结构，并全面了解该蛋白在HIV限制过程中如何寡聚；(Ii)确定A3G如何与单链DNA结合并催化胞苷脱氨；以及(Iii)解剖A3G和A3F的Vif相互作用表面，以充分了解关键的异同。我们还将使用新型A3G抑制剂和小肽作为分子探针来剖析DNA脱氨机制的各个阶段。每个研究人员都将把他/她的专业知识应用于这些目标中的每一个，我们的团队将努力建立A3F和A3G如何介导HIV-1限制以及VIF如何抵消这些多方面和强大的先天免疫防御的“大图景”。总体而言，该计划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开发和实施通过利用A3/VIF轴发挥作用的新型艾滋病毒/艾滋病疗法。

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.