Fig. 5: TFIP11 is required for U4/U6.U5 tri-snRNP stability.

a Immunoprecipitation (IP) of endogenous Sm proteins from HeLa cell extracts pre-treated or not with RNAse A followed by western blotting (WB) for the indicated proteins. b Immunoprecipitation (IP) of endogenous TFIP11 from HeLa cell extracts followed by western blotting (WB) for the indicated snRNP-specific proteins. c Immunoprecipitation (IP) of endogenous Sm protein from extracts of HeLa cells mock-transfected (No siRNA) or transfected for 48 h with one TFIP11 siRNA (siTFIP11 #1) or control siRNA (siCtr) followed by western blotting (WB) of the indicated snRNP-specific proteins. d, e Glycerol-gradient fractionation. d Northern blotting (NB) analysis of U1, U2, U4, U5 and U6 snRNAs isolated from a glycerol-gradient (10–30%) fractionation of nuclear extracts from siCtr- and siTFIP11 #1-transfected cells 72 h post-transfection. NB data shown are representative of two independent experiments. e Western blotting (WB) analysis of indicated proteins isolated from the same glycerol-gradient (10–30%) fractions. f Densitometry scanning of NB autoradiographs for each U snRNA in each fraction of nuclear extracts from siCtr- and siTFIP11 #1-transfected cells. g Western blotting for the indicated proteins on the nuclear extracts (NE) of HeLa cells transfected for 72 h with control siRNA (siCtr) or with TFIP11 siRNA (siTFIP11 #1). h, i HeLa cells were mock-transfected (No siRNA) or transfected for 48 h with one of two different TFIP11 siRNAs (siTFIP11 #1 and siTFIP11 #2) or control siRNA (siCtr), then co-stained with anti-coilin antibody (in red) and antibodies against Prp4K (h) or EFTUD2 (i) (in green). Merged channels with nuclear staining (in blue) and magnification of boxed regions are shown. Scale bar = 5 µm. Source data are provided as a Source Data file.