The monoclonal actin and cortactin antibodies were from Abcam (Cambridge, MA) and Millipore (Billerica, MA), respectively. The polyclonal ASGP-R antibodies and the monoclonal polymeric immunoglobulin A (IgA)-receptor (pIgA-R), CE9, and 5′nucleotidase (5′NT) antibodies were provided by Dr. A. Hubbard (Johns Hopkins University School of Medicine, Baltimore, MD). Cells were grown as previously described.17 On day 7, cells were treated with 50 mM of ethanol buffered with 10 mM of HEPES (pH 7.0) at 37°C for 72 hours, as previously described.12 Recombinant adenovirus encoding pIgA-R was provided by Dr. A. Hubbard. The dynamin wild-type and K44A dominant negative recombinant adenoviruses

were provided by Drs. S. Schmid and H. Damke (Scripps, La Jolla, CA). After 48 hours of ethanol exposure, cells were infected for 1 hour at 37°C, as previously described.18 Cells were washed with complete medium and incubated learn more for an additional 18-20 hours in the continued absence or presence of ethanol to allow protein expression. Then, 50 nM of TSA was added during the last 30 minutes of virus expression. Immunoprecipitations were performed as previously described.20 In general, Birinapant cells were lysed in 1%

nonyl phenoxypolyethoxyethanol, 150 mM of NaCl, 50 mM of Tris, and 1 mM of ethylene diamine tetraacetic acid (pH 7.5) on ice for 30 minutes and cleared by centrifugation at 120,000×g for 30 minutes at 4°C. Antidynamin antibodies (0.5-1 μg) were added and recovered with Protein G agarose (Thermo Fisher Scientific Inc., Waltham, MA). The precipitated fractions were resuspended in Laemmli sample buffer and boiled for 3 minutes. Samples were immunoblotted with antibodies specific to AP2 (1:1,000), CHC (1:2,000), cortactin (1:2,500), actin (1:2,500), or dynamin (1:2,500). Immunoreactivity was detected using enhanced chemiluminescence (PerkinElmer,

Crofton, MD). Cells were fixed on ice with 4% paraformaldehyde/phosphate-buffered saline (PFA/PBS) for 1 minute and permeabilized with ice-cold methanol for 10 minutes. Cells were processed for indirect immunofluorescence, medchemexpress as previously described,21 using antibodies against ASGP-R (1:1,000), pIgA-R (1:200), AP2 (1:100), or CHC (1:1,000). Fluorophore-conjugated secondary antibodies were used at 5 μg/mL. To label cortactin (1:100), cells were permeabilized with PEM (100 mM of PIPES, 1 mM of ethylene glycol tetraacetic acid, 1 mM of MgCl2; pH 6.8), containing 0.1% saponin and 8% sucrose for 2 minutes and fixed at room temperature (RT) with 4% PFA/PBS for 30 minutes. To visualize membrane-associated dynamin (1:100), cells were permeabilized with 0.1% Triton X-100/ PEM/sucrose for 2 minutes at RT and fixed in methanol for 5 minutes at −20°C. Epifluorescence was visualized using an Olympus BX60 Microscope (Opelco, Inc., Dulles, VA). Images were collected using a Coolsnap HQ2 digital camera (Photometrics, Tucson, AZ) and IPLabs image analysis software (BioVision Technologies, Inc., Chester Springs, PA).