The BM2 protein of influenza B virus is synthesized in the late phase of infection and incorporated into virions as a subviral component.
The BM2 protein of influenza B virus is synthesized in the late phase of infection and incorporated into virions as a subviral component.
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DOI：
10.1099/0022-1317-80-10-2573
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发表时间：
1999-10
期刊：
影响因子：
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通讯作者：
Takato Odagiri;Jin Hong;Y. Ohara
中科院分区：
文献类型：
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作者：
Takato Odagiri;Jin Hong;Y. Ohara
流感B病毒基因组RNA片段7编码M1和BM 2蛋白。BM 2蛋白是通过从RNA片段7转录的双顺反子mRNA中重叠的终止-起始五核苷酸处的偶联翻译终止-再起始机制合成的。然而，这种蛋白的特征和功能仍不清楚。在本研究中，通过使用针对流感病毒株B/Yamagata/1/73的BM 2蛋白产生的抗血清来表征BM 2蛋白。在感染有B/Yamagata病毒的细胞中，alphaBM 2抗体特异性检测分子量为12 kDa的BM 2蛋白以及分子量为17 kDa的多肽。当感染的细胞用32 Pi标记并与alphaBM 2抗体免疫沉淀时，32 P标记的17 kDa多肽被特异性沉淀。在酪蛋白激酶抑制剂CKI-7的存在下，17 kDa和BM 2蛋白质的合成被完全抑制，虽然其他病毒蛋白质，除了聚合酶蛋白，正常合成。这些结果表明，17 kDa物质是BM 2蛋白的磷酸化形式。这些物质基本上是在感染后期合成的，并在整个感染过程中定位于细胞质中。此外，它们被运输到质膜，然后被并入病毒体。因此，这些结果表明BM 2和17 kDa蛋白对于流感B病毒的生命周期是必需的。
The influenza B virus genome RNA segment 7 encodes the M1 and BM2 proteins. The BM2 protein is synthesized by a coupled translational termination-reinitiation mechanism at the overlapping stop-start pentanucleotide in a bicistronic mRNA transcribed from RNA segment 7. However, features and functions of this protein remain unclear. In this study the BM2 protein was characterized by using an antiserum raised to the BM2 protein of influenza virus strain B/Yamagata/1/73. In cells infected with B/Yamagata virus the alphaBM2 antibody specifically detected the BM2 protein with a molecular mass of 12 kDa and also a polypeptide with a molecular mass of 17 kDa. When infected cells were labelled with 32Pi and immunoprecipitated with the alphaBM2 antibody, the 32P-labelled 17 kDa polypeptide was specifically precipitated. In the presence of casein kinase inhibitor CKI-7 the synthesis of the 17 kDa and BM2 proteins was completely suppressed, although other viral proteins, except for the polymerase protein, were synthesized normally. These results suggest that the 17 kDa species is a phosphorylated form of the BM2 protein. These species were substantially synthesized in the late phase of infection and localized in the cytoplasm throughout infection. Moreover, they were transported to the plasma membrane and thereafter were incorporated into virions. These results therefore suggest that the BM2 and the 17 kDa proteins are necessary for the life-cycle of influenza B virus.