Mouse hepatitis coronavirus nucleocapsid phosphorylation.
Mouse hepatitis coronavirus nucleocapsid phosphorylation.
复制标题
小鼠肝炎冠状病毒核衣壳磷酸化。
DOI：
10.1007/978-0-387-33012-9_28
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发表时间：
2006
影响因子：
--
通讯作者：
Hogue,BrendaG
中科院分区：
文献类型：
--
作者：
White,TianaC;Hogue,BrendaG
1.介绍包装大型病毒RNA基因组到一个螺旋核衣壳内的成熟病毒M蛋白。1，2，3 N还显示在包装信号和5 '前导序列处结合病毒RNA，所述5'前导序列是病毒基因组RNA和所有亚基因组RNA共有的。4，5，6除了在病毒体结构和RNA结合中的作用外，N还被认为在病毒复制中发挥作用。冠状病毒复制子无论是表达N还是在存在反式提供的N蛋白的情况下复制，都显示出比不存在N的情况下转染的复制子增强的活性。[7]这一证据使人们普遍认为N蛋白参与了病毒的转录和/或复制复合体。综上所述，N显然是一种动态病毒蛋白。N蛋白被磷酸化，这是整个家族保守的特征。小鼠肝炎病毒A59（MHV），一种II组冠状病毒，被用作研究N蛋白磷酸化的模型。数据表明，在病毒生命周期中，BCV和MHV的N蛋白至少以两种磷酸化形式存在，这由不同的分子量表示。[8]数据还表明，只有一种形式被包装成病毒体。因此，N蛋白的磷酸化可能在病毒组装中起作用。或者，蛋白质的不同磷酸化形式可以在组装、复制和/或转录中执行不同的功能。为了开始理解磷酸化在N提供的任何功能中所起的作用，我们已经开始鉴定成熟病毒体和感染细胞中哪些氨基酸被磷酸化。这份报告的重点是初步鉴定的网站是磷酸化的成熟病毒粒子。质谱法正在用于识别N蛋白内许多预测的磷酸化位点中的哪些在病毒粒子和感染细胞中实际上被修饰。从纯化的病毒粒子中初步鉴定出N蛋白上的丝氨酸389和丝氨酸424
1. INTRODUCTION packages the large viral RNA genome into a helical nucleocapsid within the mature viral M protein. 1, 2, 3 N has also been shown to bind viral RNA at both the packaging signal and the 5’leader sequence that is common to both viral genomic RNA and all subgenomic RNAs. 4, 5, 6 In addition to its role in virion structure and RNA binding, N has been implicated as playing a role in viral replication. Coronavirus replicons either expressing N or replicating in the presence of N protein supplied in trans showed enhanced activity over replicons transfected without the presence of N. 7 This evidence has led to the general opinion that N protein is involved in the transcription and/or replication complexes of the virus. Taken together, N is clearly a dynamic viral protein. The N protein is phosphorylated, a feature conserved across the family. Mouse hepatitis virus A59 (MHV), a group II coronavirus, is being used as a model to study N protein phosphorylation. Data suggest that the N protein of BCV and MHV exists in at least two phosphorylated forms, indicated by differing molecular weights, during the viral life cycle. 8 Data also suggests that only one form is packaged into virions. Thus, phosphorylation of the N protein may play a role in viral assembly. Alternatively, different phosphorylated forms of the protein may perform distinct functions in assembly, replication, and/or transcription. To begin understanding the role that phosphorylation plays in any of the functions provided by N, we have begun identifying which amino acids are phosphorylated in the mature virion and in infected cells. This report focuses on preliminary identification of sites that are phosphorylated in the mature virion. Mass spectrometry is being used to identify which of the many predicted phosphorylation sites within the N protein are actually modified in the virion and in infected cells. Serine 389 and serine 424 have been preliminarily identified on the N protein from purified virions