FIGURE 6.
Analysis of the effect of CED mutations on TGF-β1 biosynthesis and latent complex stability. Conditioned medium from cells transfected with wild type (WT) or CED variants of TGF-β1 was initially analyzed by Western blot using a TGF-β1 mAb (A). Subsequently, medium was treated with acid to release mature TGF-β1 from the SLC and then neutralized. The ability of LAP to reassociate with TGF-β1 was monitored over time by a TGF-β1 ELISA (B). The presence of monomeric TGF-β1 precursor in the medium of cells transfected with the CED variants (A) suggested that these mutations affect LAP dimerization. To address this possibility, wild type and CED mutant LAP variants were generated and expressed transiently in HEK-293T cells (C). Error bars, S.D.