HIV Nucleocapsid Protein Nucleic Acid Chaperone Activity

描述（由申请人提供）：HIV-1核衣壳蛋白（NC）是一种短的碱性核酸结合蛋白，具有两个锌指结构域，每个锌指结构域均含有不变的CCHC金属离子结合基序。成熟蛋白（55个氨基酸残基）由Gag前体的蛋白水解裂解产生，并存在于病毒颗粒的内部，在那里它与基因组RNA紧密结合。NC或Gag中的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、病毒RNA上的引物放置、逆转录和整合。这些功能中的许多依赖于NC的核酸伴侣活性，即，催化核酸构象重排的能力，导致最稳定的结构。NC如何促进核酸重排的细节尚未完全了解。拟议的工作使用的生物化学测定和新的生物物理方法相结合，研究各种寡核苷酸系统，旨在提高我们目前的理解NC在各种核酸重组事件中的作用，是关键的逆转录。拟议工作的具体目标是：（1）探索HIV-1 NC介导的TAR RNA/DNA退火机制;（2）探索HIV-1 NC介导的链交换反应的一般机制;和（3）进行比较研究与HTLV-1、RSV和MLV NC蛋白。NC的显著生物学特性及其在逆转录病毒复制中的核心作用使NC成为新的HIV治疗剂的有吸引力的靶点。从相关的逆转录病毒系统研究其他NC蛋白质将提供洞察这些不同的NC蛋白质的功能的不同方式。从这些研究中获得的NC的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，如果可以确定所有逆转录病毒NC蛋白的共同机制，功能和干预措施，人们可以设想快速控制新出现的逆转录病毒，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 two 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, one could envision rapid control of newly emerging retroviruses, which are also likely to share these common features.