【摘要】 PcG蛋白主要以PRC1和PRC2两组复合物的形式存在,通过参与核小体组蛋白翻译后修饰等机制,发挥调控靶基因转录的功能.PRC1复合体中的RING1A/B具有使组蛋白H2AK119泛素化的活性;PRC2中的EZH2具有使组蛋白H3K27三甲基化的活性,形成PRC1锚定到核小体上的位点.PcG蛋白的表达特征具有发育阶段和细胞类型时空特异性.长链非编码RNA等反式作用因子能募集PcG蛋白结合于靶基因,发挥靶向作用.本文就PcG蛋白功能、构成的时空特异性、募集机制及其与疾病发生的关系研究进展做一综述.更多还原

【Abstract】 The polycomb-group(PcG) proteins function as epigenetic transcriptional regulators through multiple mechanisms,including most important histone post-translational modifications.PcG proteins are categorized into two major groups,polycomb repressive complex 1(PRC1) and 2(PRC2).The RING1 A /B subunits of PRC1 are capable to ubiquitinate histone H2 A at lysine 119(H2AK119ub).The EZH2 subunit of PRC2 triple methylates the lysine 27 of histone H3 tail(H3K27me3),which is responsible for canonical PRC1 recruitment.PcG proteins are expressed in somatic cells in a spatiotemporal specific manner during tissue development.Trans-acting factors and long non-coding RNAs can recruit PcG complexes to their target genes.The current knowledge about the function of PcG proteins,the patterns of their expressions,the targeting mechanisms,and their connection with diseases are discussed in this review.更多还原