The formin DAAM1 regulates the deubiquitinase activity of USP10 and integrin homeostasis

In this study, a yeast two-hybrid screen revealed a novel binding partner for USP10, the formin, DAAM1. We found that DAAM1 binds to and inhibits USP10's DUB activity through the FH2 domain of DAAM1 independent of its actin functions. The USP10/DAAM1 interaction was also supported by proximity ligation assay (PLA) in primary human corneal fibroblasts. Treatment with TGFβ1 significantly increased USP10 and DAAM1 protein expression, PLA signal, and co-localization to actin stress fibers. DAAM1 siRNA knockdown significantly reduced co-precipitation of USP10 and DAAM1 on purified actin stress fibers, and β1- and β5-integrin ubiquitination. This resulted in increased αv-, β1-, and β5-integrin total protein levels, αv-integrin recycling, and extracellular fibronectin (FN) deposition. Together, our data demonstrate that DAAM1 inhibits USP10's DUB activity on integrins subsequently regulating cell surface αv-integrin localization and FN accumulation.PMID:37562219 | DOI:10.1016/j.ejcb.2023.151347

Source: European Journal of Cell Biology - August 10, 2023 Category: Cytology Authors: Andrew T Phillips Edward F Boumil Arunkumar Venkatesan Christine Tilstra-Smith Nileyma Castro Barry E Knox Jessica L Henty-Ridilla Audrey M Bernstein Source Type: research