Bansal O B, Stokes A, Bansal A, Bishop D, Roy P
Department of International Health, University of Alabama at Birmingham, 35294, USA.
J Virol. 1998 Apr;72(4):3362-9. doi: 10.1128/JVI.72.4.3362-3369.1998.
The smallest RNA segment (S10) of bluetongue virus (an orbivirus, family Reoviridae) encodes two closely related nonstructural proteins, the 229-amino-acid (aa) NS3 and the 216-aa NS3A. The proteins are found in glycosylated and nonglycosylated forms in infected cells (X. Wu, H. Iwata, S.-Y. Chen, R. W. Compans and P. Roy J. Virol. 66:7104-7112, 1992). The NS3/NS3A proteins have two hydrophobic domains (aa 118 to 141 and 162 to 182) and two potential asparagine-linked glycosylation sites (aa 63 and 150), one of which is located between the hydrophobic domains. To determine whether these features were used in the mature protein forms, we generated a series of mutants of the S10 gene and expressed them by using the vaccinia virus T7 polymerase transient-expression system. Our data indicate that both hydrophobic domains of NS3 span the cell membrane and that only the site at aa 150 is responsible for N-linked glycosylation of the NS3 proteins.
蓝舌病毒(呼肠孤病毒科环状病毒属)最小的RNA片段(S10)编码两种紧密相关的非结构蛋白,即229个氨基酸(aa)的NS3和216个氨基酸的NS3A。在受感染细胞中可发现这些蛋白的糖基化和非糖基化形式(X. Wu、H. Iwata、S.-Y. Chen、R. W. Compans和P. Roy,《病毒学杂志》66:7104 - 7112,1992年)。NS3/NS3A蛋白有两个疏水结构域(氨基酸118至141和162至182)以及两个潜在的天冬酰胺连接糖基化位点(氨基酸63和150),其中一个位于疏水结构域之间。为确定这些特征在成熟蛋白形式中是否有用,我们构建了一系列S10基因的突变体,并使用痘苗病毒T7聚合酶瞬时表达系统进行表达。我们的数据表明,NS3的两个疏水结构域均跨越细胞膜,并且只有氨基酸150处的位点负责NS3蛋白的N - 连接糖基化。