摘要
Polycomb group complex (PcG)作为发挥转录抑制作用的重要表观遗传调控复合物参与发育、衰老以及肿瘤发生等重要生理过程。Pc G家族成员,包括PRC1 (Polycomb repressive complex 1)与PRC2 (Polycomb repressive complex 2)两种复合物,各组分间功能既协同,又不失特性,色素框同源蛋白(Chromobox homolog CBX)是PRC1的主要核心蛋白,其家族的成员之一CBX2近年来成为研究的热点。本研究综述了CBX2基因的发现、基因和蛋白质的结构组成及其在人和鼠不同组织的表达情况,阐述了CBX2在哺乳动物性发育中的作用及研究进展,发现CBX2除参与PcG复合体发挥转录抑制作用外,还具有基因转录激活作用,它作为哺乳动物性别决定级联中SRY (Sex region of Y chromosome)的上游基因可直接激活靶基因SF1/NR5A1的表达,如果CBX2基因突变或缺失将使雄性小鼠发生性反转,在人类中造成46,XY性发育障碍(disorders of sex development, DSD),为进一步研究CBX2基因在动物性发育调控中的作用提供依据。
Polycomb group(Pc G), as a key epigenetic regulatory complex, plays a role in inhibiting transcription and is involved in a diverse range of processes such as development, senescence and tumorigenesis, etc. PcG consists of two complexes, PRC1(Polycomb repressive complex 1) and PRC2(Polycomb repressive complex 2), in which each component coordinates but presents distinct function. Chromobox homolog(CBX) is the major core protein of PRC1,and one of its family members, CBX2, has become a hot topic recently. This review summarized the discovery of CBX2, the structural composition of genes and proteins, and its expression in different tissues of human and mouse,and expounded the role of CBX2 in sexual development of mammalian and the research progress. It was found that in addition to participating in the PcG complex to inhibit transcription, CBX2 also played a role of gene transcriptional activation. As the upstream gene of SRY(Sex region of Y chromosome) in sex determination cascade of mammalian, CBX2 could directly activate the expression of target gene, SF1/NR5 A1. If the CBX2 gene was mutated or deleted, it would cause sexual reversal in male mice, and 46 XY DSD(disorders of sex development) in humans. These might provide a basis for further exploraton of the role of the CBX2 in animal sexual development regulation.
引文
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