Epigenetic regulation of cytomegalovirus major immediate-early promoter activity in transgenic mice.
The expression of genes in transgenic mice is known to be influenced by the site of integration even when they carry their own promoter elements and transcription factor binding sites. The cytomegalovirus (CMV) promoter, a strong promoter often used for transgene expression in mammalian cells in culture, is known to be silenced by DNA methylation and histone deacetylation but there is no report on the role of histone methylations in its regulation. We generated two transgenic lines carrying green fluorescence protein coding gene as reporter driven by cytomegalovirus major immediate-early promoter/enhancer. We observe that silencing of CMV promoter is dependent on the site of transgene integration, except in testis, and the nature of DNA and histone methylations strongly correlate with the expression status of the reporter. We find that silenced CMV promoter interacts in vivo, with Methyl CpG binding protein 2 (MeCP2), a recruiter of histone deacetylases (HDACs) and histone (H3K9) methyl transferase. Histone H3K4methylation, the active chromatin mark, is also associated with silenced promoter, suggesting bivalent marking of the promoter and its susceptibility to reactivation on induction.
Mehta
Abhishek Kumar
AK
Dr. B. R. Ambedkar Center for Biomedical Research, University of Delhi, North Campus, Delhi, India.
Majumdar
Subeer S
SS
Alam
Parwez
P
Gulati
Neerja
N
Brahmachari
Vani
V
D000818:Animals; D000956:Antigens, Viral / Q000235:genetics* / Q000378:metabolism; D002478:Cells, Cultured; D002843:Chromatin / Q000378:metabolism; D047369:Chromatin Immunoprecipitation; D018899:CpG Islands; D003587:Cytomegalovirus / Q000235:genetics*; D019175:DNA Methylation; D044127:Epigenesis, Genetic; D015967:Gene Expression Regulation, Viral; D020868:Gene Silencing; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006655:Histone Deacetylases; D006657:Histones / Q000378:metabolism; D006801:Humans; D017874:Immediate-Early Proteins / Q000235:genetics* / Q000378:metabolism; D007668:Kidney / Q000166:cytology / Q000378:metabolism; D051783:Methyl-CpG-Binding Protein 2 / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008822:Mice, Transgenic; D011401:Promoter Regions, Genetic / Q000235:genetics*; D012045:Regulatory Sequences, Nucleic Acid; D014779:Virus Replication
D000956:Antigens, Viral; D002843:Chromatin; D006657:Histones; D017874:Immediate-Early Proteins; C497393:Mecp2 protein, mouse; D051783:Methyl-CpG-Binding Protein 2; C485184:enhanced green fluorescent protein; C044582:immediate-early proteins, cytomegalovirus; D049452:Green Fluorescent Proteins; D006655:Histone Deacetylases