Panagiotidis C A, Silverstein S J
College of Physicians and Surgeons, Columbia University, New York, New York 10032, USA.
Virology. 1999 Mar 30;256(1):64-74. doi: 10.1006/viro.1999.9607.
The productive infection cycle of herpes simplex virus is controlled in part by the action of ICP4, an immediate-early gene product that acts as both an activator and repressor of transcription. ICP4 is autoregulatory, and IE-3, the gene that encodes it, contains a high-affinity binding site for the protein at its cap site. Previously, we had demonstrated that this site could be occupied by proteins found in nuclear extracts from uninfected cells. A HeLa cell cDNA expression library was screened with a DNA probe containing the IE-3 gene cap site, and clones expressing the architectural chromatin proteins HMG I and HMG Y were identified by this technique. HMG I is shown to augment binding of ICP4 to its cognate site in in vitro assays and to enhance the activity of this protein in short-term transient expression assays.
单纯疱疹病毒的增殖感染周期部分受ICP4作用的控制，ICP4是一种立即早期基因产物，它既是转录激活因子又是转录抑制因子。ICP4是自我调节的，编码它的基因IE-3在其帽位点含有该蛋白的高亲和力结合位点。此前，我们已经证明该位点可被未感染细胞核提取物中的蛋白质占据。用含有IE-3基因帽位点的DNA探针筛选HeLa细胞cDNA表达文库，通过该技术鉴定出表达结构染色质蛋白HMG I和HMG Y的克隆。在体外试验中，HMG I可增强ICP4与其同源位点的结合，并在短期瞬时表达试验中增强该蛋白的活性。
