Inhibition of furin cleavage allows secretion of full-length recombinant alpha dystroglycan (αDG) from CHO-LARGE and C2C12 cells.

A plasmid encoding a full-length cDNA for α dystroglycan (αDG) with a FLAG epitope tag at the N-terminus was transfected into CHO-LARGE cells or C2C12 cells (which were fused into myotubes after selection of transfectants). Cells were incubated with cell-permeant inhibitor of furin or plasmin, as indicated. αDG protein was purified from cell supernatant using anti-FLAG agarose and blotted using anti-FLAG or anti-αDG (IIH6) antibody. Cell lysates made from transfected C2C12 myotube cultures were also blotted with antibody to beta dystroglycan (βDG).