A schematic model depicting the role of spectrin in coupling cell shape, cortical tension, and Hippo signaling. Top: WASp-mediated actin polymerization causes Hts-dependent recruitment of spectrin to cellular cortex, where spectrin tethers newly produced F-actin to cell membrane and transmits cortical actomyosin force to cell membrane to support appropriate cell shape. Bottom: Activation of myosin II in spectrin mutant PECs causes higher tension at AJs (larger arrows), leading to accumulation of Jub-Wts complex at AJs and inhibition of Wts activity, which in turn activates Yki and cell proliferation. However, cortical tension at non–AJ membrane domains is lower due to the failure of transmitting cortical actomyosin force to cell membrane (dashed arrows), leading to expanded cell diameter.