Western blotting. (A) A single 22 kD protein was detected in abraded rat tracheal epithelium (TE) with the affinity-purified anti-cav-1α antibody. (B) 22 kD (α) and 18 kD (β) cav-1 protein isoforms were detected in abraded rat TE with monoclonal affinity-purified anti-cav-1αβ antibody. (C) 21 kD (α) and 18 kD (β) bands and, close to the detection limit, a 15 kD (γ) band, corresponding to the three known cav-2-isoforms, were detected with monoclonal anti-cav-2 antibody in abraded TE. (A-C) Heart and lung homogenates served as controls. (D) In contrast to wild-type mice (WT), no cav-1α was detected in lung homogenates of cav-1-deficient mice (cav-1-/-). (E) Also, no cav-2 protein was detected in lung homogenates of cav-1-deficient mice. The 50 kD bands in all lanes were due to the secondary antibodies that detected the heavy chain of mouse IgG.