Arginine methylation of Sam68 and SLM proteins negatively regulates their poly(U) RNA binding activity.
Sam68 (Src substrate associated during mitosis) and its homologues, SLM-1 and SLM-2 (Sam68-like mammalian proteins), are RNA binding proteins and contain the arg-gly (RG) repeats, in which arginine residues are methylated by the protein arginine methyltransferase 1 (PRMT1). However, it remains unclear whether the arginine methylation affects an RNA binding. Here, we report that methylation of Sam68 and SLM proteins markedly reduced their poly(U) binding ability in vitro. The RG repeats of Sam68 bound poly(U), but arginine methylation of the RG repeats abrogated its poly(U) binding ability in vitro. Overexpression of PRMT1 increased arginine methylation of Sam68 and SLM proteins in cells, which resulted in a decrease of their poly(U) binding ability. The results suggest that the RG repeats conserved in Sam68 and SLM proteins may function as an auxiliary RNA binding domain and arginine methylation may eliminate or reduce an RNA binding ability of the proteins.
Rho
Jaerang
J
Gene Therapy Research Unit, Korea Research Institute of Bioscience and Biotechnology, Yusong, Daejeon 305-806, Republic of Korea.
Choi
Seeyoung
S
Jung
Cho-Rok
CR
Im
Dong-Soo
DS
D048868:Adaptor Proteins, Signal Transducing / Q000737:chemistry / Q000378:metabolism*; D001120:Arginine / Q000737:chemistry / Q000378:metabolism*; D001665:Binding Sites; D002460:Cell Line; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D007668:Kidney / Q000378:metabolism*; D008745:Methylation; D011485:Protein Binding; D012313:RNA / Q000737:chemistry / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000378:metabolism*
D048868:Adaptor Proteins, Signal Transducing; D004268:DNA-Binding Proteins; C489559:KHDRBS1 protein, human; C485572:KHDRBS2 protein, human; D016601:RNA-Binding Proteins; D012313:RNA; D001120:Arginine