Single-component optogenetic tools for inducible RhoA GTPase signaling

We created optogenetic tools to control RhoA GTPase, a central regulator of actin organization and actomyosin contractility. RhoA GTPase, or its upstream activating GEF effectors, were fused to BcLOV4, a photoreceptor that can be dynamically recruited to the plasma membrane by a light-regulated protein-lipid electrostatic interaction with the inner leaflet. Direct membrane recruitment of these effectors induced potent contractile signaling sufficient to separate adherens junctions in response to as little as one pulse of blue light. Cytoskeletal morphology changes were dependent on the alignment of the spatially patterned stimulation with the underlying cell polarization. RhoA-mediated cytoskeletal activation induced YAP nuclear localization within minutes and subsequent mechanotransduction, verified by YAP-TEAD transcriptional activity. These single-component tools, which do not require protein binding partners, offer spatiotemporally precise control over RhoA signaling that will advance the study of its diverse regulatory roles in cell migration, morphogenesis, and cell cycle maintenance.