Influenza B virus BM2 protein is an oligomeric integral membrane protein expressed at the cell surface
Influenza B virus BM2 protein is an oligomeric integral membrane protein expressed at the cell surface
复制标题
DOI：
10.1016/s0042-6822(02)00083-1
复制
发表时间：
2003-02-01
期刊：
影响因子：
3.7
通讯作者：
Lamb, RA
中科院分区：
文献类型：
--
作者：
Paterson, RG;Takeda, M;Lamb, RA
乙型流感病毒BM2蛋白含有109个氨基酸残基，它是从开放阅读框中的双链mRNA翻译而来，相对于基质（M1）蛋白为+2个核苷酸。BM2的氨基酸序列包含一个疏水区（残基7-25），可以作为跨膜锚。BM2蛋白的性质分析，包括洗涤溶解性、碱pH 11的不溶性、膜组分的漂浮性和表位标记免疫细胞化学，表明BM2蛋白是除血凝素（HA）、神经氨酸酶（NA）和NB糖蛋白外，乙型流感病毒编码的第四个完整膜蛋白。生化分析表明BM2蛋白在膜上呈NoutCin取向，荧光显微镜显示BM2在细胞表面表达。由于BM2蛋白仅具有一个疏水结构域，缺乏可切割的信号序列，因此它是除甲型流感病毒的M-2、NB和CM2蛋白外的另一种III型完整膜蛋白。化学交联研究表明，BM2蛋白是寡聚物，很可能是四聚体。比较BM2蛋白TM结构域的氨基酸序列与甲型流感病毒质子选择性离子通道M2蛋白TM结构域的氨基酸序列是有趣的，因为在BM2蛋白（H-19和W-23）中发现的M-2蛋白残基（分别为H-37和W-41）处于相同的相对位置和间距。(C) 2003 Elsevier Science（美国）版权所有。
The influenza B virus BM2 protein contains 109 amino acid residues and it is translated from a bicistronic mRNA in an open reading frame that is +2 nucleotides with respect to the matrix (M1) protein. The amino acid sequence of BM2 contains a hydrophobic region (residues 7-25) that could act as a transmembrane (TM) anchor. Analysis of properties of the BM2 protein, including detergent solubility, insolubility in alkali pH 11, flotation in membrane fractions, and epitope-tagging immunocytochemistry, indicates BM2 protein is the fourth integral membrane protein encoded by influenza B virus in addition to hemagglutinin (HA), neuraminidase (NA), and the NB glycoprotein. Biochemical analysis indicates that the BM2 protein adopts an NoutCin orientation in membranes and fluorescence microscopy indicates BM2 is expressed at the cell surface. As the BM2 protein possesses only a single hydrophobic domain and lacks a cleavable signal sequence, it is another example of a Type III integral membrane protein, in addition to M-2, NB, and CM2 proteins of influenza A, B, and C viruses, respectively. Chemical cross-linking studies indicate that the BM2 protein is oligomeric, most likely a tetramer. Comparison of the amino acid sequence of the TM domain of the BM2 protein with the sequence of the TM domain of the proton-selective ion channel M2 protein of influenza A virus is intriguing as M-2 protein residues critical for ion selectivity/activation and channel gating (H-37 and W-41, respectively) are found at the same relative position and spacing in the BM2 protein (H-19 and W-23). (C) 2003 Elsevier Science (USA). All rights reserved.