组蛋白的泛素化与去泛素化修饰

Ubiquitination and Deubiquitination of Histone

泛素在真核生物体内广泛存在,泛素化修饰是转录后的修饰方式之一;组蛋白是染色质的主要成分之一,与基因的表达有密切关系。组蛋白的泛素化修饰与经典的蛋白质的泛素调节途径不同,不会导致蛋白质的降解,但是能够招募核小体到染色体、参与X染色体的失活、影响组蛋白的甲基化和基因的转录。组蛋白的去泛素化修饰同样与染色质的结构及基因表达密切相关。组蛋白的泛素化和磷酸化、乙酰化、甲基化修饰之间还存在协同和级联效应。

Ubiquitin （Ub） is ubiquitously distributed and highly conserved throughout eukaryotic organisms. Ubiquitination is one of the modifications in post-transcription of genes. Histone is a component of chromatin and plays a vital role in regulating gene expression. The ubiquitination of histone does not lead to proteolysis, which differs from classical pass-way of ubiquitination of protein. Ubiquitinated histones can recruit nucleosome into chromatin, affect histone methylation and gene transcription, and are also involved in X chromosome inactivation. Ubiquitination and deubiquitination of histone is closely related to alteration of structure of chromtin and gene expression. There are synergistic and cascade effect among histone ubiquitination, deubiquitination, phosphonation, acetylation and methylation.