Related Experiment Video
Updated: May 24, 2026

Yeast As a Chassis for Developing Functional Assays to Study Human P53
Published on: August 4, 2019
Inhibition of p53 transcriptional activity by human cytomegalovirus UL44
Yejin Kwon1, Mi-Na Kim, Eun Young Choi
1Department of Microbiology and Immunology, Seoul National University Medical Research Center, Seoul 110-799, Korea.
Abstract:
Human cytomegalovirus (HCMV) stimulates cellular synthesis of DNA and proteins and induces transition of the cell cycle from G(1) to S and G(2) /M phase, in spite of increased amounts of p53 in the infected cells. The immediate early protein IE2-86 kDa (IE86) tethers a transcriptional repression domain to p53; however, its repression of p53 function is not enough to abrogate the G(1) checkpoint function of p53. Other HCMV proteins that suppress the activity of p53 were investigated in this study. Of the HCMV proteins that bind to p53 when assessed by immunoprecipitation and immunoblot analysis, HCMV UL44 was chosen as a candidate protein. It was found that reporter gene containing p53 consensus sequence was activated by transfection with wild type p53, but when plasmids of p53 with IE86 or UL44 were co-transfected, p53 transcriptional activity was decreased to 3-7% of the p53 control in a dose-dependent manner. When the deletion mutant of UL44 was co-transected with p53, the carboxyl one-third portion of UL44 had little effect on inhibition of p53 transcriptional activity. The amount of mRNA p21 was measured in H1299 by real time PCR after transfection of the combination of p53 and UL44 vectors and it was found that p21 transcription by p53 was inhibited dose-dependently by UL44. Increased G0/G1 and decreased S phases in p53 wild type-transfected H1299 cells were recovered to the level of p53 mutant type-transfected ones by the additional transfection of UL44 in a dose-dependent manner. In conclusion, the transcriptional activity of p53 is suppressed by UL44 as well as by IE86.
Related Concept Videos
Abnormal Proliferation
Negative Regulator Molecules
Cytomegalovirus Disease
Eukaryotic Transcription Inhibitors
Eukaryotic transcription inhibitors usually contain two distinct domains, a DNA...
Inhibitors of Viral Protein Synthesis
DNA Damage can Stall the Cell Cycle

