The following antibodies were used: mouse anti-β-dsytroglycan (7D11; Developmental Studies Hybridoma Bank), rabbit anti-CAV3 (peptide sequence CGFEDVIAEPEGTYSFDE; Luetterforst et al., 1999 (link)), mouse anti-CAV3 (#610421; BD Biosciences), rabbit anti-Cavin4 (peptide sequence CGDDESLLLELKQSS; Lo et al., 2015 (link)), rabbit anti-Cavin4b (peptide sequence GEESEVPMYDMKQLS), mouse anti-BIN1 (clone 99D, #05-449-C; Millipore), mouse anti-actin (α-sarcomeric; clone 5C5 #A2172; Sigma-Aldrich), anti-rabbit Alexa Fluor 555 secondary antibody (#A-31572; Invitrogen), and anti-mouse Alexa Fluor 488 secondary antibody (#A-21202; Invitrogen).