Role of arginine-methyltransferase for quality control of protein maturation

我们发现蛋白精氨酸甲基转移酶（PRMT）在内质网（ER）应激条件下上调。PRMT1蛋白水平在内质网应激源tunicamycin作用下升高，且呈时间依赖性。PRMT1因XBP1过表达而上调。相比之下，PRMT1敲低（KD）的细胞在未处理的条件下（非应激条件下）显示er伴侣GRP78的增加。此外，这些细胞引起高尔基复合体的异常定位，导致高尔基相关蛋白如GM130、TGN38、Fut8的增加。最后，将PRMT1-YFP转染到PRMT1-KD细胞中，恢复了高尔基复合体的异常积累。这些结果表明，PRMT1调节与内质网功能相关的高尔基复合体的结构和功能。

We discovered upregulation of Protein Arginine Methyltransferases (PRMT) under endoplasmic reticulum (ER) stress condition. Protein level of PRMT1 is increased by ER stressor tunicamycin, time-dependently. PRMT1 is upregulated by XBP1 overexpression. In contrast, cells knocked-down (KD) of PRMT1 showed increase of ER-chaperone GRP78 under untreated condition (non-stress condition). Moreover, these cells cause abnormal localization Golgi complex, resulting increase of the Golgi-related proteins such as GM130, TGN38, Fut8. Finally, to transfect PRMT1-YFP into PRMT1-KD cells, the abnormal accumulation of Golgi complex was recovered.These results suggest that PRMT1 regulates the structure and the function of Golgi complex, associated to ER function.