招募与强化:维持表观遗传沉默。
Recruitment and reinforcement: maintaining epigenetic silencing.
机构信息
National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China.
College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China.
出版信息
Sci China Life Sci. 2018 May;61(5):515-522. doi: 10.1007/s11427-018-9276-7. Epub 2018 Mar 13.
Cells need to appropriately balance transcriptional stability and adaptability in order to maintain their identities while responding robustly to various stimuli. Eukaryotic cells use an elegant "epigenetic" system to achieve this functionality. "Epigenetics" is referred to as heritable information beyond the DNA sequence, including histone and DNA modifications, ncRNAs and other chromatin-related components. Here, we review the mechanisms of the epigenetic inheritance of a repressive chromatin state, with an emphasis on recent progress in the field. We emphasize that (i) epigenetic information is inherited in a relatively stable but imprecise fashion; (ii) multiple cis and trans factors are involved in the maintenance of epigenetic information during mitosis; and (iii) the maintenance of a repressive epigenetic state requires both recruitment and self-reinforcement mechanisms. These mechanisms crosstalk with each other and form interconnected feedback loops to shape a stable epigenetic system while maintaining certain degrees of flexibility.
细胞需要在维持自身特性的同时,适当平衡转录稳定性和适应性,以对各种刺激做出强烈响应。真核细胞利用一种精巧的“表观遗传”系统来实现这一功能。“表观遗传学”是指超越 DNA 序列的可遗传信息,包括组蛋白和 DNA 修饰、ncRNAs 和其他染色质相关成分。在这里,我们综述了抑制性染色质状态的表观遗传遗传机制,重点介绍了该领域的最新进展。我们强调:(i)表观遗传信息以相对稳定但不精确的方式遗传;(ii)在有丝分裂过程中,多个顺式和反式因子参与维持表观遗传信息;(iii)抑制性表观遗传状态的维持需要募集和自我强化机制。这些机制相互作用,并形成相互关联的反馈环,在保持一定程度灵活性的同时,塑造稳定的表观遗传系统。