DBH·BiP complex formation and the effect of pharmacological chaperone. Forced expression of A348E but not wild-type DBH robustly induced BiP mRNA (A) and protein (B) expression in CHO cells. C, immunoprecipitation (IP) with anti-BiP/GRP78 antibodies shows that expression of A348E but not wild-type DBH dramatically increased formation of a DBH and BiP/GRP78 complex. D, effect of a chemical chaperone, glycerol, and lower growth temperature (27 °C) on secretion of DBH proteins in culture medium of CHO cells. Error bars, S.D.