title: Inactivation of the very strong HCMV immediate early promoter by DNA CpG methylation in vitro.
abstract: The influence of DNA methylation in vitro on the activity of the very strong human cytomegalovirus (HCMV) major immediate early (IE) modulator/enhancer/promoter region was investigated by transient transfection experiments of premonocytic HL-60 cells. While sequence-specific methylation of the major IE enhancer and/or modulator with the cytosine methyl-transferases FnuDII, HhaI and HaeIII had no significant effect, the promoter activity was completely repressed by methylation of the cytosine in 5'-CpG sites with the Spiroplasma methyltransferase SssI. Addition of TNF-alpha or PMA which are strong stimulators of HCMV major IE enhancer/promoter activity in premonocytic HL-60 cells had no effect on repression. Inactivation of the IE enhancer/promoter via methylation by M.SssI could be partially alleviated by co-transfection with an excess of untranscribable highly methylated DNA. These results indicate that a methyl-CpG binding factor is involved as mediator in the inhibitory effect of HCMV enhancer/promoter methylation. Taken together, the HCMV major IE enhancer/ promoter has been shown to be susceptible to transcriptional inactivation by methylation of the cytosines in CpG dinucleotides, a process that is proposed to play a modulatory role in viral latency.
authors.affiliation: Institute of Medical Virology, Humboldt University Medical School, Berlin, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Prösch
authors.forename: J
authors.initials: J
authors.lastname: Stein
authors.forename: K
authors.initials: K
authors.lastname: Staak
authors.forename: C
authors.initials: C
authors.lastname: Liebenthal
authors.forename: H D
authors.initials: HD
authors.lastname: Volk
authors.forename: D H
authors.initials: DH
authors.lastname: Krüger
mesh_terms: D000956:Antigens, Viral / Q000235:genetics*; D001483:Base Sequence; D001667:Binding, Competitive; D003587:Cytomegalovirus / Q000235:genetics*; D004247:DNA / Q000378:metabolism; D015257:DNA-Cytosine Methylases / Q000378:metabolism*; D015226:Dinucleoside Phosphates / Q000378:metabolism*; D004742:Enhancer Elements, Genetic; D015967:Gene Expression Regulation, Viral; D018922:HL-60 Cells; D006801:Humans; D017874:Immediate-Early Proteins / Q000235:genetics*; D008745:Methylation; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
chemical_list: D000956:Antigens, Viral; D004247:DNA; D015257:DNA-Cytosine Methylases; D015226:Dinucleoside Phosphates; D017874:Immediate-Early Proteins; D013755:Tetradecanoylphorbol Acetate; D014409:Tumor Necrosis Factor-alpha; C044582:immediate-early proteins, cytomegalovirus; C015772:CpG dinucleotide; C081573:DNA modification methylase SssI