Wright D A, Staprans S I, Spector D H
Department of Biology, University of California, San Diego, La Jolla 92093.
J Virol. 1988 Jan;62(1):331-40. doi: 10.1128/JVI.62.1.331-340.1988.
In this report, we identify the proteins encoded by the 2.2-kilobase class of early transcripts arising from a region of the strain AD169 human cytomegalovirus genome (map units 0.682 to 0.713) which contains cell-related sequences. These transcripts, encoded by adjacent EcoRI fragments R and d, have a complex spliced structure with 5' and 3' coterminal ends. Antiserum directed against a synthetic 11-amino-acid peptide corresponding to the predicted amino terminus of the proteins was generated and found to immunoprecipitate four infected-cell proteins of 84, 50, 43, and 34 kilodaltons. These proteins were phosphorylated and were associated predominantly with the nuclei of infected cells. The 43-kilodalton protein was the most abundant of the four proteins, and its level of expression remained relatively constant throughout the infection. Expression of the other proteins increased as the infection progressed. Pulse-chase analysis failed to show a precursor-product relationship between any of the proteins. A comparison of the [35S]methionine-labeled tryptic peptide maps of the four proteins from infected cells and an in vitro-generated polypeptide derived from the putative first exon showed that all four infected-cell proteins were of viral origin and contained a common amino-terminal region.
在本报告中，我们鉴定了由人巨细胞病毒AD169株基因组一个区域（图谱单位0.682至0.713）产生的2.2千碱基早期转录本类别所编码的蛋白质，该区域包含与细胞相关的序列。这些转录本由相邻的EcoRI片段R和d编码，具有复杂的剪接结构，5'和3'末端共末端。针对与这些蛋白质预测氨基末端对应的合成11氨基酸肽产生了抗血清，并发现其能免疫沉淀84、50、43和34千道尔顿的四种感染细胞蛋白。这些蛋白质被磷酸化，并且主要与感染细胞的细胞核相关。43千道尔顿的蛋白质是这四种蛋白质中含量最丰富的，其表达水平在整个感染过程中保持相对恒定。随着感染的进展，其他蛋白质的表达增加。脉冲追踪分析未能显示任何一种蛋白质之间存在前体-产物关系。对感染细胞中这四种蛋白质的[35S]甲硫氨酸标记胰蛋白酶肽图谱与源自假定第一个外显子的体外产生的多肽进行比较，结果表明所有四种感染细胞蛋白均源自病毒，并且包含一个共同的氨基末端区域。
