Open AccessCytosine methylation in CTF and Spl recognition sites of an HSV tk promoter: effects on transcriptionin vivoand on factor bindingin vitro
Author(s) -
Jean Benhattar,
Peter Beard,
Josef Jiricny
Publication year - 1989
Publication title -
nucleic acids research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 9.008
H-Index - 537
eISSN - 1362-4954
pISSN - 0305-1048
DOI - 10.1093/nar/17.24.10179
Subject(s) - biology , microbiology and biotechnology , methylation , promoter , binding site , transcription (linguistics) , cytosine , transcription factor , thymidine kinase , in vivo , dna methylation , dna , gene , gene expression , herpes simplex virus , biochemistry , genetics , virus , linguistics , philosophy
We methylated specific cytosine residues within or immediately around the CTF and Sp1 binding sites of the Herpes simplex virus thymidine kinase promoter. The efficiency of transcription in vivo was reduced at least 50-fold compared with transcription from the unmethylated promoter. However, methylation within the CTF recognition site had no effect on the affinity of CTF for this site in vitro. Methylation of the Sp1 site resulted in only a small decrease in the affinity of this factor for its recognition site. In vivo studies showed that the same gene inserted in different vector DNAs was regulated differently by methylation in the promoter. These results show that cytosine methylation can inhibit transcription by a mechanism other than directly blocking the binding of transcription factors.