对大肠杆菌中表达蛋白质精氨酸甲基转移酶5的几个缺失突变体的活性研究

摘要

Protein arginine methyltransferase 5 (PRMT5) has been implicated as an important regulator of many cellular processes and signaling pathways,including chromatin remodeling,RNA splicing,DNA transcription,and cell proliferation.Therefore,structural and functional studies on PRMT5 are quite important.The full length ofPRMT5 gene was cloned into vector pGEX-4T-1,resulting in only low expression levels in Escherichia coli (E.colO.Here,it was showed that the several N-terminal amino acids deletions could result in a significant increase in the amount of soluble ft"action,while one of them did not affect the protein-arginine methyltransferase activity.And it was also found that the N-terminal 15 amino acids region of PRMT5 may be important for the catalytic activity.%蛋白质精氨酸甲基转移酶5(PRMT5)在细胞生长和信号转导方面是一个重要的调节因子,主要参与染色质重塑、RNA剪切、基因转录、细胞分化等过程.因此,对其结构和功能的研究就显得十分重要.通过大肠杆菌表达系统把全长基因PRMT5构建到pGEX-4T-1表达载体上,所得到GST标签的重组蛋白可溶性很低.为此,通过在其N端缺失不同氨基酸序列来增加其表达量,而且其中有一个缺失突变体的活性并没有发生改变.同时,还发现PRMT5 N端的前15个氨基酸对其甲基转移酶的催化活性很重要.