Figure 1.

Cytoskeletal tension promoted by the scaffolding protein Bbg at the apical cortex promotes wing disc growth by potentiating Yki activity. Bbg localizes at the apical cytocortex in proximity to E-cadherin, where it might organize a multiprotein complex, which includes Sqh and other unknown proteins. In addition, Bbg potentiates Sqh phosphorylation, which promotes actomyosin contraction. In turn, tension on actin filaments induces apical contraction, junctional tension, and wing disc growth by triggering Yki activity in part through the local recruitment of Jub, which inhibits Warts activity.