Protocol to identify mechanosensitive nuclear proteins using tunable actomyosin contractility and proximity biotinylation in mammalian cells

Mechanical forces influence a range of cellular behaviors; however, how these forces are sensed and converted into biochemical changes remains incompletely understood. A key aspect of mechanotransduction is the regulation of subcellular protein localization. Here, we present a protocol describing the engineering of cell lines with tunable actomyosin contractility combined with a proximity biotinylation strategy confined to the nucleus followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. This approach allows the identification of proteins whose nuclear localization is controlled by changes of actomyosin contractility. For complete details on the use and execution of this protocol, please refer to Tseng et al.¹.