HIV Nucleocapsid Protein Nucleic Acid Chaperone Activity

描述（由申请人提供）：HIV-1核衣壳蛋白（NC）是一种短的、基本的核酸结合蛋白，具有2个锌指结构域，每个结构域包含不变的CCHC金属离子结合基元。成熟蛋白（55个氨基酸残基）由Gag前体的蛋白水解裂解产生，存在于病毒颗粒内部，与基因组RNA紧密相关。Gag中的NC或NC结构域在病毒复制周期中具有多种功能，包括基因组RNA包装和病毒组装、在病毒RNA上放置引物、逆转录和整合。许多这些功能依赖于NC的核酸伴侣活性，即催化核酸构象重排的能力，从而导致最热动力学稳定的结构。NC如何促进核酸重排的细节尚未完全了解。这项工作将生化分析和新的生物物理方法相结合，研究各种寡核苷酸系统，旨在提高我们目前对NC在各种核酸重组事件中作用的理解，这些事件对逆转录至关重要。本研究的具体目的是：(1)探索HIV-1 nc介导的TAR RNA/DNA退火机制；(2)探讨HIV-1 nc介导的链交换反应的一般机制；(3)与HTLV-1、RSV和MLV NC蛋白进行比较研究。NC显著的生物学特性及其在逆转录病毒复制中的核心作用使NC成为HIV新疗法的一个有吸引力的靶点。研究来自相关逆转录病毒系统的其他NC蛋白将提供对这些不同NC蛋白功能的不同方式的见解。从这些研究中获得的对NC核酸结合和伴侣活性的详细了解将有助于开发有效和安全的抗艾滋病治疗策略。此外，如果能够确定所有逆转录病毒NC蛋白的共同机制、功能和干预措施，我可以设想对新出现的逆转录病毒的快速控制，这些病毒也可能具有这些共同特征。

DESCRIPTION (provided by applicant): The HIV-1 nucleocapsid protein (NC) is a short, basic, nucleic acid binding protein with 2 zinc finger domains, each containing the invariant CCHC metal-ion binding motif. The mature protein (55 amino acid residues) is produced by proteolytic cleavage of the Gag precursor and is found in the interior of the virus particle, where it is tightly associated with genomic RNA. NC or the NC domain in Gag has multiple functions during the virus replication cycle, including genomic RNA packaging and virus assembly, primer placement on viral RNA, reverse transcription, and integration. Many of these functions rely on the nucleic acid chaperone activity of NC, i.e., the ability to catalyze nucleic acid conformational rearrangements that lead to the most thermodynamically stable structure. The details of how NC facilitates nucleic acid rearrangement are not completely understood. The proposed work uses a combination of biochemical assays and novel biophysical approaches to study a variety of oligonucleotide systems designed to improve our current understanding of the role of NC in various nucleic acid restructuring events that are critical for reverse transcription. The specific aims of the proposed work are: (1) To probe the mechanism of HIV-1 NC-mediated TAR RNA/DNA annealing; (2) To probe the general mechanism of HIV-1 NC-mediated strand exchange reactions; and (3) To perform comparative studies with HTLV-1, RSV, and MLV NC proteins. The remarkable biological properties of NC and its central role in retrovirus replication make NC an attractive target for new HIV therapeutics. Studying other NC proteins from related retroviral systems will provide insights into the different ways these divergent NC proteins function. The detailed understanding of NC's nucleic acid binding and chaperone activities gained from these studies will facilitate the development of effective and safe anti-AIDS therapeutic strategies. Moreover, if common mechanisms, functions and interventions can be identified for all retroviral NC proteins, 1 could envision rapid control of newly emerging retroviruses, which are also likely to share these common features.