Kass S U, Pruss D, Wolffe A P
Laboratory of Molecular Embryology, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-5431, USA.
Trends Genet. 1997 Nov;13(11):444-9. doi: 10.1016/s0168-9525(97)01268-7.
DNA methylation has an essential regulatory function in mammalian development, serving to repress nontranscribed genes stably in differentiated adult somatic cells. Recent data implicate transcriptional repressors specific for methylated DNA and chromatin assembly in this global control of gene activity. The assembly of specialized nucleosomal structures on methylated DNA helps to explain the capacity of methylated DNA segments to silence transcription more effectively than conventional chromatin. Specialized nucleosomes also provide a potential molecular mechanism for the stable propagation of DNA methylation-dependent transcriptional silencing through cell division.
DNA甲基化在哺乳动物发育过程中具有重要的调控功能，有助于在分化的成体体细胞中稳定抑制非转录基因。最近的数据表明，甲基化DNA特异性转录抑制因子和染色质组装参与了这种对基因活性的全局控制。在甲基化DNA上组装特殊的核小体结构有助于解释甲基化DNA片段比传统染色质更有效地沉默转录的能力。特殊的核小体还为DNA甲基化依赖性转录沉默通过细胞分裂进行稳定传播提供了一种潜在的分子机制。
