Repression of genes by DNA methylation depends on CpG density and promoter strength: evidence for involvement of a methyl-CpG binding protein.

摘要: Repression of transcription from densely methylated genes can be mediated by the methyl-CpG binding protein MeCP-1 (Boyes and Bird, 1991). Here we have investigated effect methylation on with a low density methyl-CpG. We found that sparse could repress transfected completely, but inhibition was fully overcome presence in cis an SV40 enhancer. Densely genes, however, not reactivated In vitro studies showed sparsely bound weakly to interfered transcription. absence available MeCP-1, had minimal effects From these other results propose form unstable complex which prevents when promoter is weak. This disrupted strong promoter, thereby allowing gene transcribed.