Journal: European journal of cell biology
Article Title: The formin DAAM1 regulates the deubiquitinase activity of USP10 and integrin homeostasis.
doi: 10.1016/j.ejcb.2023.151347
Figure Lengend Snippet: Fig. 6. Knockdown of DAAM1 increases integrin and FN recycling. A) HCFs were transfected with siGLO or siDAAM1 and treated with TGFβ for 3 days to increase total integrin expression. siDAAM1 transfection resulted in increased expression of αv-, β1-, β5-integrins. N = 6. Statistical significance was calculated using an unpaired t-test. B) Live cell integrin recycling assay. 48 hrs post-transfection cells were blocked and treated with Ab against α5β1 or αv at 10 ug/ml for 30 min prior to cell surface stripping for 30 s. Cells were incubated for 90 min prior to incubation with 2◦Ab-488 for 30 min. N = 3 with a total of 15 images analyzed for each condition. Statistical significance was calculated using an unpaired t-test. C) HCFs were transfected with siGLO, siDAAM1, or siUSP10. After 3 days cells were lysed and subjected to Ubiquant™ ubiquitin capture ELISA. siDAAM1 reduced, whereas siUSP10 increased ubiquitination of β1 and β5. N = 4. Statistical significance was calculated using an unpaired t-test between conditions. D) Live cell FN recycling assay. HCFs were transfected with siRNA targeting USP10 or DAAM1 or control siGLO siRNA. 24hrs post transfection HCFs were loaded with biotinylated-FN for 3 h. After trypsinization (to separate cells from extracellular, non-internalized FN), HCFs were replated and imaged after 48 h. Prior to imaging by live cell confocal, cells were incubated with streptavidin-488 to detect only recycled biotinylated-FN. (Phillips et al., 2021) N = 3 with a total of 15 images analyzed for each condition. Statistical significance was calculated using one-way ANOVA. Separate exper iments demonstrated that cell architecture highlighted with SiR-actin, was non-variant between conditions E) Image analysis of D was performed with ImageJ’s Analyze Particles function. Statistical significance was calculated using one-way ANOVA.
Article Snippet: Reagents in the assay are recombinant USP10 (R&D, E-592–050), DAAM1 (Origene, TP317675), DAAM1-FH2-C purified in the Bernstein lab, and the DUB inhibitor (10 mM N-ethylmaleimide, Sigma-Aldrich).
Techniques: Knockdown, Transfection, Expressing, Stripping Membranes, Incubation, Ubiquitin Proteomics, Enzyme-linked Immunosorbent Assay, Control, Imaging, Variant Assay