The human cytomegalovirus UL74 gene encodes the third component of the glycoprotein H-glycoprotein L-containing envelope complex
The human cytomegalovirus UL74 gene encodes the third component of the glycoprotein H-glycoprotein L-containing envelope complex
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DOI：
10.1128/jvi.72.10.8191-8197.1998
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发表时间：
1998-10-01
影响因子：
5.4
通讯作者：
Compton, T
中科院分区：
文献类型：
--
作者：
Huber, MT;Compton, T
人巨细胞病毒 (HCMV) gCIII 包膜复合物由糖蛋白 H (gH；gpUL75)、糖蛋白 L (gL；gpUL115) 和与 gH dr gL 无关的第三个 125-kDa 蛋白组成（M. T. Huber 和 T. Compton, J. Virol. 71:5391-5398, 1997；L. Li, J. A.尼尔森和 W. J. Britt，J. Virol 71：3090-3097，1997）。糖苷酶消化分析表明，125-kDa 的蛋白质是含有约 125 kDa 的糖蛋白。 60 kDa 的 N-连接寡糖位于 65 kDa 或更小的肽主链上。基于这些生化特征，两个 HCMV 开放阅读框 UL74 和 TRL/IRL12 被鉴定为 125 kDa 糖蛋白的候选基因。为了鉴定编码125-kDa糖蛋白的基因，我们纯化了gCIII复合物，通过十二烷基硫酸钠-聚丙烯酰胺凝胶电泳分离各成分，并对gH和125-kDa糖蛋白进行氨基酸微序列分析。对源自纯化的 125-kDa 糖蛋白的内部肽进行微测序，得到氨基酸序列 LYVGPTK。 FASTA 搜索显示该序列与候选基因 UL74 的预测产物的氨基酸 188 至 195 精确匹配，我们将其命名为糖蛋白 O (gO)。抗 gO 抗体在免疫印迹中与大约迁移的蛋白质种类发生反应。 HCMV 感染细胞的裂解物中为 100 至 125 kDa，纯化病毒体中的蛋白质种类为 100 至 125 kDa。抗 gO 抗体还免疫沉淀 gCIII 复合物并识别 gCIII 复合物的 125-kDa 糖蛋白成分。在其他β疱疹病毒中也发现了UL74基因的位置同源物，并且UL74同源基因的预测产物的比较证明了许多保守的生化特征。
The human cytomegalovirus (HCMV) gCIII envelope complex is composed of glycoprotein H (gH; gpUL75), glycoprotein L (gL; gpUL115), and a third, 125-kDa protein not related to gH dr gL (M. T. Huber and T. Compton, J. Virol. 71:5391-5398, 1997; L. Li, J. A. Nelson, and W. J. Britt, J. Virol. 71:3090-3097, 1997). Glycosidase digestion analysis demonstrated that the 125-kDa protein was a glycoprotein containing ca. 60 kDa of N-linked oligosaccharides on a peptide backbone of 65 kDa or less. Based on these biochemical characteristics, two HCMV open reading frames, UL74 and TRL/IRL12, were identified as candidate genes for the 125-kDa glycoprotein. To identify the gene encoding the 125-kDa glycoprotein, we purified the gCIII complex, separated the components by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and subjected gH and the 125-kDa glycoprotein to amino acid microsequence analysis. Microsequencing of an internal peptide derived from purified 125-kDa glycoprotein yielded the amino acid sequence LYVGPTK. A FASTA search revealed an exact match of this sequence to amino acids 188 to 195 of the predicted product of the candidate gene UL74, which we have designated glycoprotein O (gO). Anti-gO antibodies reacted in immunoblots with a protein species migrating at ca. 100 to 125 kDa in lysates of HCMV-infected cells and,vith 100- and 125-kDa protein species in purified virions. Anti-gO antibodies also immunoprecipitated the gCIII complex and recognized the 125-kDa glycoprotein component of the gCIII complex. Positional homologs of the UL74 gene were found in other betaherpesviruses, and comparisons of the predicted products of the UL74 homolog genes demonstrated a number of conserved biochemical features.