Talin Autoinhibition Is Required for Morphogenesis

• Talin autoinhibition modulates cell-ECM adhesion stability during morphogenesis
• Failure to regulate talin autoinhibition results in delayed morphogenesis
• Defect arises as a result of cell-ECM adhesion that is too stable
• Rap1/RIAM signaling acts upstream of talin autoinhibition

SummaryThe establishment of a multicellular body plan requires coordinating changes in cell adhesion and the cytoskeleton to ensure proper cell shape and position within a tissue. Cell adhesion to the extracellular matrix (ECM) via integrins plays diverse, essential roles during animal embryogenesis and therefore must be precisely regulated [1]. Talin, a FERM-domain containing protein, forms a direct link between integrin adhesion receptors and the actin cytoskeleton and is an important regulator of integrin function [2]. Similar to other FERM proteins, talin makes an intramolecular interaction that could autoinhibit its activity [3, 4, 5 and 6]. However, the functional consequence of such an interaction has not been previously explored in vivo. Here, we demonstrate that targeted disruption of talin autoinhibition gives rise to morphogenetic defects during fly development and specifically that dorsal closure (DC), a process that resembles wound healing, is delayed. Impairment of autoinhibition leads to reduced talin turnover at and increased talin and integrin recruitment to sites of integrin-ECM attachment. Finally, we present evidence that talin autoinhibition is regulated by Rap1-dependent signaling. Based on our data, we propose that talin autoinhibition provides a switch for modulating adhesion turnover and adhesion stability that is essential for morphogenesis.

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