Ahmadian G, Chambers P, Easton A J
Department of Biological Sciences, University of Warwick, Coventry CV4 7AL, UK1.
J Gen Virol. 1999 Aug;80 ( Pt 8):2011-2016. doi: 10.1099/0022-1317-80-8-2011.
The nucleotide sequence of the M2 gene of pneumonia virus of mice (PVM) was determined. The sequence showed that the gene encoded a protein of 176 amino acids with a predicted molecular mass of 20165 Da from a major ORF, which is smaller than the equivalent proteins encoded by human, bovine and ovine respiratory syncytial (RS) viruses. The PVM M2 protein is conserved, having 41% similarity to the equivalent human RS virus protein. In common with the M2 genes of the RS viruses and avian pneumovirus (APV), the PVM mRNA also contained a second ORF (ORF2) that partially overlaps the first ORF and which is capable of encoding a 98 residue polypeptide. No significant sequence identity could be detected between the putative M2 ORF2 proteins of PVM, APV and the RS viruses. The expression of the M2 ORF2 proteins of the pneumoviruses was investigated by using monospecific antisera raised against GST fusion proteins. Western blot analysis demonstrated the presence of polypeptides encoded by M2 ORF2 of PVM and RS virus corresponding with those predicted by in vitro translation studies, but this was not the case for APV. The PVM polypeptide was present as three distinct products in vivo. The PVM and RS virus polypeptides were also detected in cells by immunofluorescence, which showed that both were present in the cytoplasm with a degree of localization in inclusion bodies. No APV M2 ORF2 protein could be detected in vivo. The RS virus M2 ORF2 polypeptide was shown to accumulate during infection and the potential implications of this are discussed.
测定了小鼠肺炎病毒（PVM）M2基因的核苷酸序列。该序列显示，该基因从一个主要开放阅读框编码一个由176个氨基酸组成的蛋白质，预测分子量为20165 Da，比人、牛和羊呼吸道合胞体（RS）病毒编码的相应蛋白质小。PVM M2蛋白具有保守性，与相应的人RS病毒蛋白有41%的相似性。与RS病毒和禽肺炎病毒（APV）的M2基因一样，PVM mRNA也包含第二个开放阅读框（ORF2），它与第一个开放阅读框部分重叠，能够编码一个98个残基的多肽。在PVM、APV和RS病毒的推定M2 ORF2蛋白之间未检测到显著的序列同一性。通过使用针对GST融合蛋白产生的单特异性抗血清，研究了肺炎病毒M2 ORF2蛋白的表达。蛋白质印迹分析表明，PVM和RS病毒M2 ORF2编码的多肽与体外翻译研究预测的多肽相对应，但APV并非如此。PVM多肽在体内以三种不同的产物形式存在。通过免疫荧光也在细胞中检测到了PVM和RS病毒多肽，这表明两者都存在于细胞质中，并在包涵体中有一定程度的定位。在体内未检测到APV M2 ORF2蛋白。已证明RS病毒M2 ORF2多肽在感染期间会积累，并讨论了其潜在影响。
