SUMO and ubiquitin modifications in henipavirus matrix trafficking and function

副粘病毒家族包含许多全球关注的人类和动物病原体。尼帕病毒属的尼帕病毒（NiV）和亨德拉病毒（HeV）是感染人类的毒性最强的副粘病毒。NiV和HeV从其天然果蝠宿主向人类的人畜共患传播可导致死亡率超过90%。最近在全球范围内发现的新型艾滋病毒分支突出了这些人畜共患病毒可能在全球出现。更好地了解高致病性病毒的基本病理生物学对于制定治疗方案至关重要。副粘病毒基质(M)蛋白对病毒组装和出芽至关重要。虽然副粘病毒完全在细胞质中复制，但我们发现在感染早期，NiV-M蛋白首先靶向细胞核，然后泛素化，随后定位到质膜。这种泛素调控的核细胞质运输对其介导病毒组装和出芽的能力至关重要，并且在几种副粘病毒属的病毒中是保守的。进一步的初步数据表明NiV-M是被SUMOylated的，并且细胞的SUMOylated状态影响NiV-M的功能。我们的总体目标是确定SUMO和泛素修饰在基质运输和功能中的作用。我们的目标是了解同源SUMO和泛素蛋白酶体途径组分如何协调调节HNV-M蛋白的复杂细胞内运输行为，并揭示这些翻译后修饰在病毒复制生命周期中发挥的功能作用。我们的驱动假设是特定的SUMO和泛素蛋白酶体途径组分协调基质蛋白核停留的时空控制，这使得基质的适当膜靶向对病毒组装和出芽至关重要。了解HNV-M的基本细胞生物学可能会揭示宿主-病原体相互作用，从而可能成为治疗干预的目标。为了质疑我们的驱动假说，我们提出以下具体目标：目的1：确定HNV-M中哪些赖氨酸被修饰。目的2：询问HNV-M与E3 ub连接酶相互作用的后果。目的3：评估SUMOylation和Nup358/RanBP2（一种SUMO E3连接酶）在HNV-M蛋白核运输和功能中的作用。目标4：定义与病毒复制和致病适应性相关的基质翻译后修饰的功能作用。

The Paramyxovirus family contains numerous human and animal pathogens of global concern. Nipah (NiV) and Hendra (HeV) viruses of the Henipavirus (HNV) genus are the most virulent paramyxoviruses that infect humans. Zoonotic transmission of NiV and HeV from their natural fruit bat reservoirs to humans can result in mortality rates in excess of 90%. The recent discovery of novel clades of HNV across the globe highlights the possible global emergence of these zoonotic viruses. A better understanding of the basic pathobiology of highly pathogenic viruses is critical for developing therapeutic options. The Paramyxovirus matrix (M) protein is critical to viral assembly and budding. Although paramyxoviruses replicate entirely in the cytoplasm, we found that early during infection, NiV-M protein is first targeted to the nucleus prior to ubiquitination and subsequent localization to the plasma membrane. This ubiquitin-regulated nuclear-cytoplasmic trafficking of M is critical for its ability to mediate viral assembly and budding, and is conserved across viruses from several Paramyxovirus genera. This application is spurred by a confluence of further preliminary data suggesting that NiV-M is SUMOylated, and that the SUMOylation state of the cell affects NiV-M's function. Our overall goal is to determine the role of SUMO and ubiquitin modifications in matrix trafficking and function. Our objective is to understand how cognate SUMO and ubiquitin proteasome pathway components coordinately regulate the complex intracellular trafficking behavior of HNV-M proteins, and to uncover the functional role(s) that these post-translational modifications play in the virus replicative life cycle. Our driving hypothesis is that specific SUMO and ubiquitin proteasome pathway components coordinate the spatial-temporal control of the matrix protein's nuclear sojourn, which enables the proper membrane targeting of matrix that is critical for virus assembly and budding. Understanding the basic cell biology of HNV-M might reveal host-pathogen interactions that could be targeted for therapeutic interventions. To interrogate our driving hypothesis, we propose the following Specific Aims: AIM 1: Determine which lysines in HNV-M are modified. AIM 2: Interrogate the consequences of HNV-M interactions with E3 Ub-ligases. AIM 3: Evaluate the role of SUMOylation and Nup358/RanBP2 (a SUMO E3 ligase) in the nuclear trafficking and function of HNV-M proteins. AIM 4: Define the functional roles for matrix post-translational modifications in relation to viral replication and pathogenic fitness.