Fig. 4: Alternative splicing of LRRFIP2 regulates histone methyltransferase activity of CARM1 through specific interaction.
From: ESRP1-regulated isoform switching of LRRFIP2 determines metastasis of gastric cancer
a List of LRRFIP2 binding partner candidates analyzed from the mass spectrometry-base crosslinking assay. b Immunoprecipitation assay showing the interaction between HA-CARM1 and Flag-LRRFIP2 variant 2 or 3 in 293 T cells. c Immunoprecipitation assay showing the interaction between LRRFIP2 variant 2 or 3 and endogenous CARM1. d Immunoblot analysis showing H3R17me2a, histone H3, and CARM1 in control and CARM1 siRNA-treated cells. e Immunoblot analysis showing H3R17me2a, histone H3 and Flag in LRRFIP2 variant 2 and 3-overexpressing MKN28 cells. f Immunoblot and RT-PCR analysis showing H3R17me2a, histone H3 and LRRFIP2 in control and exon 7-deleted cell lines. g RT-PCR analysis showing expression of SERPINE1, CARM1, LRRFIP2 in LRRFIP2 variant 2 or 3-overexpressing MKN28 cells, with CARM1 knockdown by siRNA transfection. h, i qChIP analysis of the human SERPINE1 promoter with antibodies to CARM1, H3R17me2a in h LRRFIP2 variant 2 and 3-overexpressing MKN28 cell lines and i LRRFIP2 variant 3 exon7 deleted MKN1 cell lines. j Representative IHC images showing SERPINE1 and H3R17me2a expression in metastasized liver tissues from Fig. 2k (left) and H-score scatter plots of the IHC staining (right). Original magnification, _200X. Scale bar, 50 µm. k Transwell migration assay and Matrigel invasion assay of MKN1 cells with CARM1 knockdown (left) and bar graphs showing number of invaded and migrated cells (right), respectively, following staining with crystal violet. Original magnification, _40X. Scale bar, 0.5 mm. b–g The representative results were obtained from at least three independent experiments. h, i Data are representative mean ± SD of three independent samples (N = 3). j Data are representative mean ± SD of six independent samples (n = 6). k Data are representative mean ± SD of three independent experiments (N = 3). All P values were calculated by unpaired two-tailed Student’s t tests. Source data are provided in the Source Data file.
