ADAM12-Lb is poorly processed and is retained in a pre-Golgi compartment.

<p>(A) Proteolytic processing of ADAM12-La and ADAM12-Lb in MCF10A cells. Cells with stable expression of ADAM12 proteins were selected with puromycin after retroviral infection. Total cell lysates were analyzed by Western blotting. The full-length protein is indicated by arrowhead, and the processed form after prodomain removal is denoted with arrow. (B) Mobility shift analysis of ADAM12-La and ADAM12-Lb after endoglycosidase H (Endo H) treatment. The nascent full-length protein and the processed form are indicated with arrowhead and arrow, respectively. The deglycosylated full-length species is denoted with grey arrow. (C) Cell surface biotinylation of MCF10A cells stably expressing ADAM12-La or ADAM12-Lb. Biotinylated proteins were isolated on Neutravidin agarose and subjected to SDS-PAGE and Western blotting. Input (1/40 of the sample volume) refers to total cell lysates prior to Neutravidin binding, and eluate (1/2 of the sample volume) refers to biotinylated proteins that bound to the resin. β-actin, an interacellular protein, is not biotinylated and does not bind to Neutravidin.