The mechanosensitive protein Zyxin influences Hippo signalling and tissue growth via adherens junctions and basal spot junctions in Drosophila

Physical forces like tension and compression have a central role in the growth and morphogenesis of tissues. Cell-cell junctions and the actin cytoskeleton are key mediators of physical forces and influence activity of signalling networks like the Hippo pathway. Here, we show that the mechanosensitive proteins Zyxin and Ajuba work in concert to limit Hippo signalling and promote Drosophila epithelial tissue growth. Zyxin recruits both Ajuba and the central Hippo pathway kinase Warts to adherens junctions and basal spot junctions, and limit Warts activity by segregating it from Hippo pathway activator proteins. Zyxin also promotes the transmission of actomyosin tension to adherens junctions in growing epithelial tissues, indicating conservation of this function. Thus, we provide new insights into how Zyxin couples mechanical cues and Hippo pathway-dependent tissue growth and highlight the importance of basal spot junctions and their associated actomyosin network in epithelial tissue development.