Zhang Zhiqing, Zhang Feng, Bai Shimeng, Qiao Jiaming, Shen Honglin, Huang Fang, Gao Shuangquan, Li Shaowei, Gu Ying, Xia Ningshao
State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen, People's Republic of China.
National Institute of Diagnostics and Vaccine Development in Infectious Disease, School of Life Sciences, Xiamen University, Xiamen, People's Republic of China.
Biotechnol Appl Biochem. 2018 Nov;65(6):807-815. doi: 10.1002/bab.1662. Epub 2018 Apr 25.
The HIV-1 Gag precursor protein (p55) is the main structural protein comprising the matrix (MA/p17), capsid (CA/p24), and nucleocapsid (NC/p7) proteins, and is uniquely responsible for virion assembly within the virus life cycle. The MA protein plays a critical role in plasma membrane targeting and envelope glycoprotein (Env) uptake during virion assembly. Yet, when viral infection occurs, the MA protein may also be involved in virion uncoating, dissociating from the plasma membrane, and participating in the nuclear importation process. Thus, the MA protein contains a reversibly membrane-binding signal and varied conformation to govern its subcellular localization and biological functions. However, these purported different conformations of the MA protein during assembly are poorly understood, especially in terms of its function as a component of the precursor protein. In this study, we characterized a panel of monoclonal antibodies against MA that showed discrete reactivity to p55, an intermediate (p41), and the final p17 mature form. We suggest that these antibodies could be used to track the different conformations of MA during the HIV-1 life cycle, particularly during HIV-1 assembly and maturation, and contribute to structure determination of MA or MA precursors. These antibodies would also have clinical value, including serving for therapeutic strategy to interfere AIDS progression, reagent in diagnostic kit for the detection of virion-free p17 or p17 derived from virion lysate.
HIV-1 群特异性抗原前体蛋白（p55）是主要的结构蛋白，由基质蛋白（MA/p17）、衣壳蛋白（CA/p24）和核衣壳蛋白（NC/p7）组成，在病毒生命周期中对病毒体装配起着独特作用。MA 蛋白在病毒体装配过程中对质膜靶向和包膜糖蛋白（Env）摄取起关键作用。然而，病毒感染发生时，MA 蛋白也可能参与病毒体脱壳，从质膜解离，并参与核输入过程。因此，MA 蛋白含有可逆的膜结合信号和多样的构象来调控其亚细胞定位和生物学功能。然而，目前对装配过程中 MA 蛋白这些所谓的不同构象了解甚少，尤其是其作为前体蛋白组分的功能方面。在本研究中，我们鉴定了一组针对 MA 的单克隆抗体，它们对 p55、一种中间体（p41）和最终的 p17 成熟形式表现出不同的反应性。我们认为这些抗体可用于追踪 HIV-1 生命周期中 MA 的不同构象，特别是在 HIV-1 装配和成熟过程中，并有助于确定 MA 或 MA 前体的结构。这些抗体还具有临床价值，包括作为干扰艾滋病进展的治疗策略、用于检测无病毒体 p17 或病毒体裂解物衍生的 p17 的诊断试剂盒中的试剂。
