Arginine methylation-mediated FXR1 binding with RNAs in cancer cells

FXR1 is an RNA binding protein and it is post traslationally modified by a methyltrasferase to facilitate its RNA binding activity FXR1 is methylated by PRMT5, an arginine methyltransferase, to promote its stability and facilitate its association with mRNAs. Both genetic and small molecule PRMT5 inhibition failed to methylate recombinant as well as the endogenous FXR1, resulting in protein instability and downregulation of FXR1 target mRNA levels in HNSCC cells. To study the differentially regulated gene under the loss of PRMT5, we knocked- down the PRMT5 using shRNA and confirmed the transcript and protein levels using qRT PCR and immunoblot respectively. PRMT5 shRNA and control shRNA plasmids were used to transfect UMSCC74B cells. Cells were incubated at the appropriate condition for 72 h and mRNA levels and the protein expression were analyzed by qRT-PCR and immunoblot respectively.