Fig. 4: PRMT1 interacts with and methylates UBE2m, and this interaction is enhanced in tubular epithelial cells with COM treatment.

A Silver-stained SDS-PAGE gel of the immunoprecipitation product. B MS/MS spectra of the peptide “FSPSGIFGAFQR-COOH.” Peaks in color are the detected b (green) and y (red) ions. C The volcano plot indicating potential target proteins of PRMT1. D Molecular docking pattern diagram of PRMT1 and UBE2m. E Representative images of immunofluorescence staining of UBE2m (green) and PRMT1 (red) in HK-2 cells treated with COM. Scale bars = 50 μm. F Reciprocal co-IP analysis of PRMT1 and UBE2m in HK-2 cells with COM treatment. IgG was used as a negative control. G Recombinant GST-PRMT1 was incubated with recombinant His-UBE2m, followed by GST-pulldown and immunoblotting analysis with GST and His antibodies. H Endogenous UBE2m was immunoprecipitated in cells from the indicated groups. The mono-methylation (me1) level of UBE2m was determined using immunoblotting. I PLA detection of PRMT1 and UBE2m interaction in HK-2 cells from the indicated groups. Scale bars = 50 μm. J The me1 level of UBE2m was determined using immunoblotting after UBE2m was immunoprecipitated in HK-2 cells with PRMT1 knockdown or overexpression.