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bioRxiv · 10.1101/2022.05.06.490842

Mechanism of the cadherin-catenin F-actin catch bond interaction

Wang, A.·Dunn, A. R.·Weis, W. I.
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Abstract

Mechanotransduction at cell-cell adhesions is crucial for the structural integrity, organization, and morphogenesis of epithelia. At cell-cell junctions, ternary E-cadherin/{beta}-catenin/E-catenin complexes sense and transmit mechanical load by binding to F-actin. The interaction with F-actin, described as a two-state catch bond, is weak in solution but is strengthened by applied force due to force-dependent transitions between weak and strong actin-binding states. Here, we provide direct evidence from optical trapping experiments that the catch bond property principally resides in the E-catenin actin-binding domain (ABD). Consistent with our previously proposed model, deletion of the first helix of the five-helix ABD bundle enables stable interactions with F-actin under minimal load that are well-described by a single-state slip bond, even when E-catenin is complexed with {beta}-catenin and E-cadherin. Our data argue for a conserved catch bond mechanism for adhesion proteins with structurally similar ABDs. We also demonstrate that a stably bound ABD strengthens load-dependent binding interactions between a neighboring complex and F-actin, but the presence of the other E-catenin domains weakens this effect. These results provide mechanistic insight to the cooperative binding of the cadherin-catenin complex to F-actin, which regulate dynamic cytoskeletal linkages in epithelial tissues.

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Wang, A., Dunn, A. R., Weis, W. I.. 2022-05-06. Mechanism of the cadherin-catenin F-actin catch bond interaction. https://doi.org/10.1101/2022.05.06.490842

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