Bryans M, Kass S, Seivwright C, Adams R L
Department of Biochemistry, University of Glasgow, UK.
FEBS Lett. 1992 Aug 31;309(1):97-102. doi: 10.1016/0014-5793(92)80748-6.
Methylation of a plasmid containing the SV40 promoter linked to the chloramphenicol acetyl transferase (CAT) gene, with either murine DNA methylase or methylase SssI results in inhibition of the expression of the reporter gene after transfection into cultured cells. Methylation of the plasmid with the methylases HhaI and HpaII has no effect on the expression of this gene. Protein-DNA interactions in the SV40 promoter are not affected by the presence of methylcytosine suggesting that inactivation results from the formation of an inactive chromatin structure that is dependent on the high CG content of the plasmid.
用鼠源DNA甲基转移酶或SssI甲基转移酶对含有与氯霉素乙酰转移酶（CAT）基因相连的SV40启动子的质粒进行甲基化，在转染到培养细胞后会导致报告基因的表达受到抑制。用HhaI和HpaII甲基转移酶对该质粒进行甲基化对该基因的表达没有影响。SV40启动子中的蛋白质-DNA相互作用不受甲基胞嘧啶存在的影响，这表明失活是由于形成了一种依赖于质粒高CG含量的无活性染色质结构所致。
