Samples were harvested in MIB lysis buffer, subjected to SDS-PAGE chromatography and transferred to PVDF membranes before western blotting with primary antibodies. For pMYPT and pMLC2 blots, cells were harvested in a buffer containing 1% (w/v) SDS, 50 mM Tris pH 7.5 supplemented with protease and phosphatase inhibitors buffer and were passed through QIAshredder columns (Qiagen, 79654) (21 (link)). For the list of primary antibodies used, see (Data file S10). Secondary HRP-anti-rabbit and HRP-anti-mouse were obtained from ThermoFisher Scientific. SuperSignal West Pico and Femto Chemiluminescent Substrates (Thermo Scientific) were used to visualize blots. Western blot images were quantified using the Analyze>Gels function in Image J open source software (National Institutes of Health). Optical density values were normalized by sum (fig. S2, G–J) or by a fixed point (Fig. 4E, Fig. 5B and Fig. 7F) (45 (link)). Phosphorylated proteins were normalized to loading control, then normalized to total abundance of the respective protein.