Regulation of Expression of the M143 Promoter of Mouse Cytomegalovirus
The objective of this research is to examine the regulation of an essential gene (m143) in MCMV that has sequence and functional homology to HCMV genes IRS1/TRS1. All of these prevent the shutdown of protein synthesis that is an antiviral defense. Little is known about the regulation of these genes at either the transcriptional or posttranscriptional levels. Sequential deletion mutant analysis of the m143 promoter was done in the context of an SEAP reporter plasmid. The results indicated that viral proteins are required for activation and the presence of repressor-binding sites and activation-binding sites. EMSA shows that SP1 may be important for the activation. Two important viral transcriptional regulators IE1 and IE3, each alone weakly activates the m143 promoter, but together synergize to efficiently activate this promoter. The absence of repression with co-transfection experiments support repression by other viral proteins. Such studies may lead to novel treatments for cytomegalovirus infection.