CAREER: Structural Interplay Between Chromatin Remodeling and Lentiviral Integration

这项研究将揭示像HIV这样的病毒是如何劫持宿主蛋白质机制并永久改变宿主基因组以维持感染的。这项工作将产生原子结构，揭示病毒和宿主蛋白之间的相互作用，介导病毒遗传信息整合到宿主基因组中。由此产生的结构和生化数据将为理解这些相互作用如何导致生产性感染提供一个机制框架，并将揭示如何阻止这一过程，并导致新的抗病毒药物，或可用于基因治疗。这些研究主题将教授给处于科学发展不同阶段的听众。综合研究和教育计划包括对本科生和研究生进行先进的科学训练，让学生在世界知名的学术研究机构中接触复杂的科学项目，并向贫困的高中生介绍结构生物学和病毒学，以激励他们的科学发展。包括HIV在内的所有慢病毒都有一个区别于其他病毒的重要特征——它们能够通过一种称为整合的催化过程，将其RNA基因组的互补DNA拷贝整合到目标宿主的染色质中。整合在靶细胞中建立了永久和不可逆的感染，并有助于病毒致病性。虽然我们了解慢病毒整合的基本机制，但我们对宿主因子在这一过程中所起的作用知之甚少。具体地说，有一个突出但完全未被重视的现象，即染色质重塑伴随着成功的整合。宿主染色质重塑子的破坏导致影响慢病毒感染的不同表型，但重塑子如何组装、参与染色质并最终与慢病毒成分相互作用以影响整合尚不清楚。利用低温电子显微镜和生化方法，本研究将探讨：(1)不依赖于atp的染色质重塑子如何重组染色质，并利用这种重组状态在催化整合之前参与病毒机制；(2) atp依赖性染色质重塑子如何在催化整合后参与并重组整合的病毒DNA，以建立具有转录能力的原病毒。这项工作将提供一个机制分子框架，阐明宿主染色质重塑物如何与病毒机制相互作用以促进整合，并为未来广泛研究负责染色质重塑和慢病毒整合的分子机器之间的结构、功能和交叉对话奠定基础。这项工作是由分子生物物理学和遗传机制集群共同资助的。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This research will uncover how some viruses like HIV hijack host protein machinery and permanently alter the host genome to sustain infection. The work will produce atomic structures that reveal the interactions between viral and host proteins that mediate the integration of viral genetic information into the host genome. The resulting structures and biochemical data will provide a mechanistic framework for understanding how these interactions lead to productive infection and will reveal insights into how this process may be blocked, and lead to novel anti-virals, or can be exploited for gene therapy. These research themes will be taught to audiences at different stages of their scientific development. The integrated research and education plan includes the advanced scientific training of both undergraduate and graduate students, the exposure of students to complex scientific programs within a world-renowned academic research institution, and the introduction of both structural biology and virology to under-privileged high-school students to inspire their scientific development. All lentiviruses, including HIV, are characterized by an important hallmark that distinguishes them from other viruses — their ability to integrate a complementary DNA copy of their RNA genome into target host chromatin through a catalytic process called integration. Integration establishes a permanent and irreversible infection in the target cell and contributes to viral pathogenicity. Although we understand the basic mechanisms underlying lentiviral integration, we know comparatively little about the role that host factors play in this process. Specifically, there is the prominent but wholly underappreciated phenomenon of chromatin remodeling that accompanies successful integration. Disruption of host chromatin remodelers leads to distinct phenotypes affecting lentiviral infection, but how the remodelers are assembled, engage chromatin, and ultimately interplay with lentiviral components to affect integration remain unclear. Using cryogenic electron microscopy and biochemical methods, this research will investigate: (1) how ATP-independent chromatin remodelers reorganize chromatin and exploit this reorganized state to engage viral machinery prior to catalytic integration; and (2) how ATP-dependent chromatin remodelers engage and reorganize integrated viral DNA after catalytic integration to establish a transcriptionally competent provirus. This work will provide a mechanistic molecular framework that elucidates how host chromatin remodelers interact with viral machinery to facilitate integration and establish a foundation for future work that broadly examines the structure, function, and cross-talk between the molecular machines responsible for chromatin remodeling and lentiviral integration.This work was jointly funded by the Molecular Biophysics and Genetic Mechanisms clusters.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.