Stinski M F, Thomsen D R, Stenberg R M, Goldstein L C
J Virol. 1983 Apr;46(1):1-14. doi: 10.1128/JVI.46.1.1-14.1983.
The immediate early genes of human cytomegalovirus were characterized according to map location, RNA transcripts, and translation products. Three regions in the large unique component (0.709 to 0.751 map units) were transcribed in the presence of an inhibitor of protein synthesis (anisomycin). A single size class of polyadenylated mRNA, 1.95 kilobases (kb), was transcribed abundantly relative to the other size classes. The predominant 1.95-kb viral RNA was transcribed from right to left on the prototype arrangement of the viral genome and spanned a region of approximately 2.8 kb (0.739 to 0.751 map units). This mRNA codes for a 75,000-dalton protein that represents the predominant immediate early protein detected in infected cells. Immunoprecipitation of viral proteins synthesized in vitro as well as in vivo demonstrated that the predominant immediate early protein is synthesized as a protein of 75,000 daltons, but is presumably modified in vivo, resulting in a broad banding pattern ranging from 75,000 to 68,000 daltons. A different immediate early viral gene (0.732 to 0.739 map units) is transcribed from left to right at relatively low levels. The 3' ends of the above viral RNAs terminate at approximately 230 base pairs apart in the region of approximately 0.739 map units. Five RNA size classes ranging from 2.25 to 1.10 kb were detected, but the 1.75-kb and 1.40-kb RNA size classes were more abundant from this region. At least four minor proteins are coded by these mRNAs, with apparent molecular weights ranging from 56,000 to 16,500. Last, a 1.95-kb mRNA was transcribed from a third region (0.709 to 0.728 map units). This viral mRNA was present at relatively low concentration and coded for a minor protein of 68,000 daltons. Since immediate early gene expression of human cytomegalovirus is dominated by the synthesis of an mRNA from the region of 0.739 to 0.751 map units that codes for the predominant immediate early protein found in the infected cell, we hypothesize that this protein is the major regulatory protein influencing the switch from restricted to extensive transcription.
根据图谱位置、RNA转录本和翻译产物对人巨细胞病毒的立即早期基因进行了表征。在存在蛋白质合成抑制剂（茴香霉素）的情况下，对大的单一成分中的三个区域（0.709至0.751图谱单位）进行了转录。相对于其他大小类别的转录本，一种单一大小类别的多聚腺苷酸化mRNA（1.95千碱基，kb）被大量转录。主要的1.95-kb病毒RNA在病毒基因组的原型排列上从右向左转录，跨越大约2.8 kb的区域（0.739至0.751图谱单位）。这种mRNA编码一种75,000道尔顿的蛋白质，它是在感染细胞中检测到的主要立即早期蛋白质。对体外和体内合成的病毒蛋白进行免疫沉淀表明，主要的立即早期蛋白以75,000道尔顿的蛋白质形式合成，但可能在体内被修饰，导致出现从75,000到68,000道尔顿的宽带模式。一个不同的立即早期病毒基因（0.732至0.739图谱单位）以相对较低的水平从左向右转录。上述病毒RNA的3'末端在大约0.739图谱单位的区域中相隔约230个碱基对终止。检测到了五个大小类别从2.25至1.10 kb的RNA，但该区域中1.75-kb和1.40-kb的RNA大小类别更为丰富。这些mRNA编码至少四种次要蛋白质，其表观分子量范围为56,000至16,500。最后，从第三个区域（0.709至0.728图谱单位）转录出一种1.95-kb的mRNA。这种病毒mRNA的浓度相对较低，编码一种68,000道尔顿的次要蛋白质。由于人巨细胞病毒的立即早期基因表达主要由从0.739至0.751图谱单位区域合成的一种mRNA主导，该mRNA编码在感染细胞中发现的主要立即早期蛋白质，我们推测这种蛋白质是影响从限制性转录向广泛转录转变的主要调节蛋白。
