A CONSTITUTIVELY EXPRESSED VACCINIA GENE ENCODES A 42-KDA GLYCOPROTEIN RELATED TO COMPLEMENT CONTROL FACTORS THAT FORMS PART OF THE EXTRACELLULAR VIRUS ENVELOPE
A CONSTITUTIVELY EXPRESSED VACCINIA GENE ENCODES A 42-KDA GLYCOPROTEIN RELATED TO COMPLEMENT CONTROL FACTORS THAT FORMS PART OF THE EXTRACELLULAR VIRUS ENVELOPE
复制标题
DOI：
10.1016/0042-6822(92)90535-w
复制
发表时间：
1992-06-01
期刊：
影响因子：
3.7
通讯作者：
SMITH, GL
中科院分区：
文献类型：
--
作者：
ENGELSTAD, M;HOWARD, ST;SMITH, GL
对牛痘病毒（Western Reserve株）基因组的42-kb区域的核苷酸序列分析鉴定了具有编码具有膜糖蛋白性质的35.1-kDa多肽的潜力的基因（Smithet al.，J.Gen.Virol.72，1349 - 1376，1991）。317个氨基酸的开放阅读框（ORF）与补体控制蛋白和干扰补体功能的分泌型牛痘病毒蛋白（C28 K）具有相似性。预测的B5 R基因产物不同于后者的蛋白质，因为它包含一个C-末端疏水序列，可能是膜相关的，而不是分泌。通过北方印迹和S1核酸酶保护的转录图谱显示，该基因在感染过程中的早期和晚期都有转录，早期RNA起始位点位于晚期起始位点上游60 bp处，晚期起始位点相对于ORF位于-9至-5处。然而，预测早期和晚期mRNA的翻译产生相同的多肽。以大肠杆菌表达的B5 R的外亲水区为抗原，制备兔抗血清，免疫沉淀牛痘病毒感染细胞中的aMr 42 K蛋白。这种蛋白质的合成在整个感染，从6至7小时的峰值，其生产被抑制衣霉素，但不莫能菌素。用抗135 R血清对纯化的EEV细胞外包膜蛋白或细胞内裸病毒蛋白进行Western印迹分析，结果表明，EEV中只存在Mr 42 K蛋白和两种较高分子量的蛋白（Mr 82和87 K）。抗135 R血清可抑制IHD-1株病毒在RK 132细胞上形成彗星。B5 R是第三个编码EEV糖蛋白的牛痘基因，其他基因是病毒血凝素基因，SaIL 4 R编码Mr 22 -24 K的一组凝集素样糖蛋白。
Nucleotide sequence analysis of a 42-kb region of the vaccinia virus (strain Western Reserve) genome identified a gene with the potential to encode a 35.1-kDa polypeptide with properties of a membrane glycoprotein (Smithet al., J. Gen. Virol.72,1349–1376,1991). The 317 amino acid open reading frame (ORF) has similarity with complement control proteins and a secretory vaccinia virus protein (C28K) which interferes with complement function. The predicted B5R gene product differs from the latter protein in that it contains a C-terminal hydrophobic sequence and may be membrane-associated rather than secretory. Transcriptional mapping by Northern blotting and S1 nuclease protection showed that the gene is transcribed both early and late during infection, with the early RNA start site located 60 bp upstream of the late start site that is present at −9 to −5 by relative to the ORF. Nevertheless, translation of early and late mRNAs are predicted to produce the same polypeptide. A rabbit antiserum was raised to the predicted external hydrophilic domain of B5R expressed inEscherichia coliand used to immunoprecipitate aMr42 K protein from vaccinia-infected cells. This protein was synthesized throughout infection, with a peak from 6 to 7 hr, and its production was inhibited by tunicamycin but not monensin. Western blotting of proteins from purified extracellular enveloped virus (EEV) or intracellular naked virus with anti-135R serum showed that thisMr42 K protein and two higher molecular weight forms (Mr82 and 87 K) were present only in EEV. Anti-135R serum inhibited comet formation by the IHD-1 strain of virus on RK13cells. B5R is the third vaccinia gene shown to encode an EEV glycoprotein, the others being the virus hemagglutinin gene, and gene SaIL4R which encodes a group of lectin-like glycoproteins ofMr22–24 K.