MASTL induces GEF-H1, T pm 4.2 , and NM-2B levels. (A) Comparison of the transcriptome and proteome of MASTL-silenced MDA-MB-231 cells with known contractome-associated factors (Zaidel-Bar et al., 2015). (B) Quantification of relative mRNA levels of MASTL, ARHGEF2, TPM4 and MYH10 after MASTL silencing (48 h) in MDA-MB-231 cells based on real-time PCR analysis. (C-H) Western blot analysis and quantifications of GEF-H1, Tpm4.2, NM-2B, and MASTL protein levels in siControl and siMASTL MDA-MB-231 cells. Protein levels are normalized to GAPDH. (I) Western blot analysis of NM-2B, GEF-H1, and Tpm4.2 protein levels in siControl, siMASTL, or siMASTL + EGFP-MASTL (24 h MASTL silencing + 24 h expression of siRNA-resistant EGFP-MASTL) MDA-MB-231 cells. Mean protein levels quantified from three independent experiments relative to GAPDH are shown above indicated blots. (J) Representative F-actin (Phalloidin-Atto) and DAPI staining in siMASTL MDA-MB-231 cells transfected with EGFP-GEF-H1 for 24 h and plated on collagen for 2 h. Images were acquired on a 3i CSU-W1 spinning disk confocal. (K) Quantification of cell area based on the F-actin staining of 45 cells/condition in total (three independent experiments) from J. Data in all graphs are from three (B, F, and H) or four (D) biologically independent experiments (unpaired t test, mean ± SD). See also Table S1 and Fig. S4.