HIV Genomic RNA Structure

描述（由申请人提供）：HIV-1和HIV-2基因组RNA的5'非翻译先导区包含病毒复制所必需的序列，包括转录反激活、引物结合、剪接、衣壳化、RNA二聚化和gag基因翻译起始的信号。在一个物种内，这些非编码序列的系统发育保守性甚至可以与病毒蛋白的保守编码域相媲美，证明了它们对复制的重要性。高度的保护也突出了利用这一地区开展抗逆转录病毒战略的潜力。使用保守RNA序列作为药物靶点已经很好地建立，因为许多临床有用的抗生素识别细菌rRNA的特定片段。

DESCRIPTION (provided by applicant): The 5' untranslated leader region of HIV-1 and HIV-2 genomic RNA contains sequences essential for viral replication, including signals for transactivation of transcription, primer binding, splicing, encapsidation, RNA dimerization, and initiation of translation of the gag gene. Within a species, phylogenetic conservation of these non-coding sequences rivals even that of conserved coding domains for the viral proteins, attesting to their importance for replication. The high degree of conservation also highlights the potential to exploit this region for antiretroviral strategies. The use of conserved RNA sequences as drug targets has been well established, since many clinically useful antibiotics recognize a specific segment of bacterial rRNA. Biochemical characterization of the leader RNA of HIV-1 and HIV-2 suggests that it adopts multiple conformations that alternately display or hide RNA signals appropriate to different stages of the replication cycle. Based on the in vitro characterization of conformational isomers of HIV-2 leader RNA and upon the high degree of conservation of involved sequences, Dr. Lodmell hypothesizes that the leader region of HIV and other retroviruses is intimately involved in the regulation of several viral replicative processes, including dimerization of viral RNA, encapsidation, splicing, and protein synthesis, and that this regulation is manifested by differential presentation of the signaling structures found in the leader region. In this application, Dr. Lodmells proposes to test this hypothesis by constructing and characterizing viral mutants harboring substitution and deletion mutations designed to interfere with long- and short-range RNA interactions that were shown in vitro to be important in the modulation of RNA structure and behavior. A combination of cell culture, genetic, and biochemical approaches will be used to characterize the largely unexplored interrelationships of RNA splicing, dimerization, encapsidation, and translation in HIV types 1 and 2. The studies proposed here will aid in our overall understanding of the biochemistry and cell biology of human lentivirus replication as well as to validate the 5' leader region RNA as a potential antiretroviral target.