FIG. 6.

Induction of new protein-S promoter complex by tunicamycin. A. EMSA of the S promoter, using nuclear extracts from tunicamycin-treated (Tm) or dimethyl sulfoxide-treated control (C) HuH7 cells. Control extracts gave rise to only one shifted band (I), corresponding to binding by NF-Y, while tunicamycin-treated extracts gave rise to an additional, slower-mobility band (II). B. EMSA of the S promoter using nuclear extracts from tunicamycin-treated (Tm) HuH7 cells. A blocking antibody against NF-Y reduced the intensity of both complexes I and II (lane 3, compare with lane 2), while a supershifting antibody against XBP1 had no effect (lane 4).