The tandem Agenet domain of fragile X mental retardation protein interacts with FUS

The tandem Agenet domain (TAD) of fragile X mental retardation protein (FMRP) protein is considered to be a member of the methyl-lysine-binding Tudor domain “Royal family”. Several groups have reported that the TAD binds with methylated histones and plays a role in DNA damage responses. FMRP is a RNA-binding protein predominantly resident in cytoplasm. Therefore, in this study, we identified DDX5, FUS, EWSR1 and LSM14A as TAD-interacting proteins sensitive to F32L and/or Y96L mutation by pull-down assays and mass spectrometry. We also showed that the interaction is potentially mediated by RGG/RG motifs. Furthermore, when FMRP was knocked-down, translocation of exogenously expressed wild-type FUS and disease-related mutant R514G was observed. This study may provide a novel insight into FMRP involvement in the intracellular localization of FUS and pathology of FUS-related amyotrophic lateral sclerosis.