Fig. 8.

INF2 R218Q induces entry of MRTF into the nucleus and activation of the MRTF-SRF transcriptional complex. A Images of MRTF-GFP distribution in wt INF2, INF2 R218Q and INF2 R218Q W11L14L18A INF2 KO MDCK cells. Cells were treated or untreated with 100 nM CytD or 100 nM LatB as indicated. B Percentage of cells with MRTF-GFP in the nucleus. More than 300 cells were examined; three independent experiments. C Luciferase reporter gene activity from MDCK cells transfected with plasmids containing the luciferase gene with a minimal promoter without (minP) and with five canonical CArG boxes (5xCArG). Luciferase activity was measured after 24 h of exogenous INF2 expression. For INF2 R218Q, cells were left untreated or treated with LatB for the last 17 h. As a positive control of luciferase activity, we used cells treated with 500 nM CytD for the last 4 h. Three independent experiments were performed. D Image of an equatorial plane of MDCK cells expressing INF2 R218Q cells for 48 h that were treated or not with 100 nM LatB for the last 24 h. Nuclei were visualized with DAPI. E Percentage of cells displaying mild or severe nuclear phenotypes. More than 300 cells were examined; three independent experiments. F Percentage of surviving cells. Over 1200 cells were examined; three independent experiments. DMSO was used as vehicle. Scale bars, 10 μm. n.s., not significant; *, p < 0.05; **, p < 0.01; ***, p < 0.001