Analysis Of HSV-I ICP22 Effects On HCMV Major Immediate-Early Promoter Structure

The human cytomegalovirus (HCMV) and herpes simplex virus (HSV) are members of the herpesviridae family and are DNA viruses with complicated structures. They play a critical role in epidemiologieal studies on human viral diseases. Such viruses are important tools in basic and applied research on the molecular biology of eukaryotie gene regulatory mechanisms due to the fact that their genomes are similar to the complieated gene structures of eukaryotic cells.The human cytomegalovirus (HCMV) major immediate-early (MIE) promoter has strong transcriptional promoting capability. Its cis-acting regulatory elements form a special structure in this region that is repeated multiple times; the biological significance of these elements and their different compositions in the transcriptional promoting process remain unclear. Our results demonstrate that the HSV-I MIE protein ICP22 can generate strong repression of many viral and cellular promoters and enhancers, but as one of HSVI IE protein, has only fewer.understanding update than other four IE proteins. Hence we focus on the study of HSV-I MIE protein ICP22 can generate strong repression of many viral and cellular promoters and enhancers, and take advantage of it to analysis the transcriptional effects of ICP22 on structural HCMV MIE promotersThe exam studied the transcriptional effects of ICP22 on structural elements and mutations invarious HCMV MIE promoters by using a CAT assay. In spite of different transcriptional effects of all the elements in the presence of ICP22, the transcriptional effieiencies exhibited by mutations generated by different compositions and an entire HCMV promoter, is not the simple sum of the functions of these elements. Furthermore, the transcriptional activities of specific sequences were not affected by the presence of ICP22.