Fig. 5: Imp7 is required for YAP/TAZ nuclear accumulation in cells, and YAP function in gene expression.

a Immunoblot showing specific depletion of Imp7 with two independent siRNAs. GAPDH is the loading control. YAP and pS127 YAP blots were performed in different gels simultaneously. Quantification is shown in Supplementary Fig. 5a–d. Irrelevant lanes in the blot were removed and denoted by the dotted line. b, c Immunofluorescence (b) and quantification (c) of the localization of endogenous YAP/TAZ in RPE-1 cells transfected with either control or Imp7 siRNAs. N = 38 cells per condition from three independent experiments. P-value = 1.438e−11 (siImp7_a) and 1.709e−15 (siImp7_b). d, e Immunofluorescence (d) and quantification (e) of endogenous YAP/TAZ localization and nuclei in RPE-1 cells silenced with two independent Imp7 siRNAs. An empty vector or a X. laevis sequence of HA-Imp7, siRNA-insensitive, were overexpressed (d). Starting from the right, N = 48, 48, 48, 47, 38, and 35 cells per condition, from 3 independent experiments. P-value = 9.679e−11 (siImp7_a) and 1.928e−05 (siImp7_b). f, g Quantification of the effect on YAP/TAZ nucleo-cytoplasmic balance upon silencing of the indicated importins. N range = 30 to 37 cells per condition from 3 independent experiments. P-values from left to right: panel f, 0.229, 1.149e−05, 0.178, 0.093, 1.742e−06, 0.309, 0.114, 0.0001, 0.106, 0.316, 4.448e−26, 0.262, 0.106, 0.059, 0.287, 0.176, 0.353, 0.126, 0.261, 1.969e−07, and 1.790e−26; panel g, 0.007, 4.641e−26, 0.536, 0.525, 0.322, and 0.339. h TEAD transcriptional activity in RPE-1 cells expressing the 8× GTIIC-luciferase reporter. Cells were silenced with control or Imp7 siRNAs. Luciferase activity was analyzed as described in Methods. Data are normalized to control siRNA silenced cells. Three independent experiments were analyzed. P-value = 0.041 (siImp7_a) and 0.005 (siImp7_b). i–k qRT-PCR analysis of Ankirin1 (ANKRD), Ctgf and Cyr61 expression in RPE-1 cells transfected with either control or Imp7 siRNAs, and cultured at low/high confluence for 24 h (i), on stiff (55 kPa) or soft (2.3 kPa) substrates for 24 h (j), or under non-stretching/stretching conditions (biaxial stretching, 1 h) (k). Data were normalized to low confluence (i), stiff substrate (j), and stretching (k). Data from three biological replicates for each experiment. Statistical analysis with a two-tailed unpaired t test. Data represent mean ± s.e.m. P-values from left to right i: 0.005, 0.012, 0.009, 0.078, 0.084, 0.059, 0.074, 0.057, and 0.288; j: 0.006, 0.007, 0.009, 0.559, 0.092, 0.154, 0.548, 0.519, and 0.061; k: 0.0062, 0.0099, 0.0061, 0.263, 0.448, 0.619, 0.063, 0.071, and 0.393. Scale bar 10 µm. Raw data available in the Source Data file. P-values below or equal to 0.05, 0.01, or 0.005 were considered statistically significant and were labeled with 1, 2, or 3 asterisks, respectively.