Model of α-Cat M region mechanosensing in the Drosophila ectoderm during germband extension. (A) Schematic summarizing the distinct contributions of α-Cat M region domains to the membrane recruitment of interaction partners at low-, medium-, and high-tension cell contacts. Arrows indicate functional relationships; models of predicted corresponding M region conformations illustrated at bottom. M region domains have an inhibitory effect on each other. Cno acts in parallel with the M region and M region interactors to support AJ stability. (B) Diagram illustrating the tension landscape in the ectoderm during germband extension, showing low-tension contacts (horizontal edges), medium-tension contacts (vertical edges), and high-tension contacts (TCJs/vertices). (C) Schematic illustration of anticipated distribution of the three α-Cat conformations highlighted in A in wild-type, α-Cat-RNAi α-CatR-ΔM1 embryos, and α-Cat-RNAi α-Cat-ΔM2. See text for further discussion.