SEQUENCE-ANALYSIS OF THE MEMBRANE-PROTEIN GENE OF HUMAN CORONAVIRUS OC43 AND EVIDENCE FOR O-GLYCOSYLATION
SEQUENCE-ANALYSIS OF THE MEMBRANE-PROTEIN GENE OF HUMAN CORONAVIRUS OC43 AND EVIDENCE FOR O-GLYCOSYLATION
复制标题
DOI：
10.1099/0022-1317-73-10-2731
复制
发表时间：
1992-10-01
影响因子：
3.8
通讯作者：
TALBOT, PJ
中科院分区：
文献类型：
--
作者：
MOUNIR, S;TALBOT, PJ
利用逆转录-聚合酶链反应（RT-PCR）技术，以人冠状病毒OC 43株（HCV-OC 43）和牛冠状病毒（BCV）的特异性引物，扩增了编码HCV-OC 43膜蛋白（M）的基因。克隆的1-5 kb片段的核苷酸序列显示了一个690个核苷酸的开放阅读框（ORF），根据其与BCV的同源性鉴定其为M蛋白基因。该ORF编码230个氨基酸的蛋白质，M（r）为26416。该基因之前是基序UCCAAAC，类似于冠状病毒的共有转录起始序列。HCV-OC 43的M蛋白显示了所研究的所有冠状病毒M蛋白的典型特征：亲水性，推测外部N末端包括约10%的蛋白质，以及潜在的N-糖基化位点，随后是三个主要的疏水跨膜结构域。HCV-OC 43株M蛋白的氨基酸序列与BCV株Mebus株的氨基酸序列有94%的同源性，并且在暴露的N-末端结构域中也含有6个潜在的O-糖基化位点。事实上，在衣霉素的存在下，M蛋白的糖基化没有被抑制，这表明O-糖基化，如先前报道的BCV和鼠肝炎病毒。从衣霉素处理的细胞释放的病毒粒子含有M糖蛋白，但缺乏peplomer（S）和血凝素酯酶（HE）蛋白。因此，S和HE结构蛋白的N-糖基化的抑制阻止了它们掺入子代病毒体，这表明它们与M蛋白不同，对病毒体形态发生是不稳定的。
The gene encoding the membrane (M) protein of the OC43 strain of human coronavirus (HCV-OC43) was amplified by a reverse transcription-polymerase chain reaction of viral RNA with HCV-OC43- and bovine coronavirus (BCV)-specific primers. The nucleotide sequence of the cloned 1-5 kb fragment revealed an open reading frame (ORF) of 690 nucleotides which was identified as the M protein gene from its homology to BCV. This ORF encodes a protein of 230 amino acids with an M(r) of 26416. The gene is preceded by the motif UCCAAAC, analogous to the consensus coronavirus transcription initiation sequence. The M protein of HCV-OC43 shows features typical of all coronavirus M proteins studied: a hydrophilic, presumably external N terminus including about 10% of the protein, and a potential N-glycosylation site followed by three major hydrophobic transmembrane domains. The amino acid sequence of the M protein of HCV-OC43 has 94% identity with that of the Mebus strain of BCV, and also contains six potential O-glycosylation sites in the exposed N-terminal domain. Indeed, the glycosylation of the M protein was not inhibited in the presence of tunicamycin, which is indicative of O-glycosylation, as previously reported for BCV and murine hepatitis virus. Virions released from tunicamycin-treated cells contained the M glycoprotein but were devoid of both peplomer (S) and haemagglutinin-esterase (HE) proteins. Thus, inhibition of the N-glycosylation of the S and HE structural proteins prevented their incorporation into progeny virions, an indication that they are dispensable for virion morphogenesis, unlike the M protein.