Investigation of SV5 Budding Mechanisms

性状（由申请方提供）：包膜病毒通过病毒组分在细胞膜上组装后发生的出芽过程形成。在许多情况下，导致膜分裂和粒子释放的后期步骤似乎是通过操纵被招募到病毒组装位点的宿主机器来完成的。由于副粘病毒缺乏许多其他包膜病毒（如逆转录病毒）用于宿主因子募集的相同晚期结构域序列，导致副粘病毒颗粒释放的步骤知之甚少。最近，我们确定了一个替代序列，FPIV，在副粘病毒副流感病毒5（SV 5）的基质（M）蛋白，可以在功能上取代PTAP晚期结构域的人类免疫缺陷病毒1型（HIV-1）的出芽。在这里，我们提出的实验，以进一步研究机制，副粘病毒操纵主机，以促进病毒出芽。我们的第一个目的是研究泛素-蛋白酶体途径在SV 5出芽中的作用，通过测试SV 5 M蛋白是泛素分子附着的直接靶点的可能性。我们将尝试通过去除M蛋白FPIV序列附近的赖氨酸残基来防止这种泛素化的发生。我们的第二个目标是确定单个E类蛋白的子集，这对SV 5出芽很重要，并被招募到SV 5组装位点。我们的第三个目标是确定宿主蛋白结合到SV 5 M蛋白，测试的重要性，M相互作用蛋白的SV 5出芽，并评估是否结合发生的方式是依赖于FPIV序列。我们的第四个目的是研究SV 5 NP蛋白在病毒样颗粒出芽中的独特作用。与公共卫生的相关性：副粘病毒是造成包括麻疹和腮腺炎在内的影响人类和动物的广泛疾病的原因。更好地了解副粘病毒出芽将为未来开发针对病毒生命周期这一步骤的抗病毒药物提供基础。

DESCRIPTION (provided by applicant): Enveloped viruses are formed by a budding process that occurs following the assembly of viral components at cellular membranes. The late steps leading up to membrane fission and particle release appear to be accomplished in many cases through manipulation of host machinery that is recruited to virus assembly sites. As paramyxoviruses lack the same late domain sequences used by many other enveloped viruses, such as retroviruses, for host factor recruitment, the steps leading up to the release of paramyxovirus particles are poorly understood. Recently, we identified an alternative sequence, FPIV, within the matrix (M) protein of the paramyxovirus parainfluenza virus 5 (SV5) that can functionally substitute for the PTAP late domain of human immunodeficiency virus type 1 (HIV-1) for budding. Here, we propose experiments to further investigate mechanisms by which paramyxoviruses manipulate host machinery to facilitate virus budding. Our first aim is to investigate the role of the ubiquitin-proteasome pathway in SV5 budding by testing the possibility that SV5 M protein is a direct target for the attachment of ubiquitin molecules. We will attempt to prevent this ubiquitination from occurring through removal of lysine residues near the FPIV sequence of M protein. Our second aim is to define the subset of individual Class E proteins that is important for SV5 budding and that is recruited to SV5 assembly sites. Our third aim is to identify host proteins that bind to SV5 M protein, test the importance of M-interacting proteins for SV5 budding, and assess whether binding occurs in a way that is dependent on the FPIV sequence. Our fourth aim is to investigate the unique role of SV5 NP protein in the budding of virus-like particles. Relevance to public health: Paramyxoviruses are responsible for a wide range of diseases that affect both humans and animals, including measles and mumps. A better understanding of paramyxovirus budding will provide a foundation for future efforts towards the development of antiviral drugs that target this step of the virus lifecycle.