FIG. 3.

CIITA can activate an episomal HLA-DRA promoter in the absence of BRG-1. (A) SW-13 cells were cotransfected with the plasmid pDRA-luc, which contains the HLA-DRA promoter from −151 to +31, linked to the firefly luciferase gene along with either empty vector or increasing amounts of plasmid pCMV-CIITA. Fold transactivation (TA) was calculated by dividing the luciferase activity measured with pDRA-luc plus the indicated effector plasmid(s) by the activity obtained with the pDRA-luc plasmid alone. Error bars show the standard error of the mean for triplicate experiments. (B) Overexpression of BRG-1 or BRG-1(K798R) in HeLa or SW-13 cells has a similar, negative effect on HLA-DRA promoter activation by CIITA. The two cell lines were transfected with plasmids, as indicated below the histogram. Fold transactivation was calculated by dividing the luciferase activity measured with pDRA-luc plus the indicated effector plasmid(s) by the activity obtained with the pDRA-luc plasmid alone. Error bars represent the standard error of the mean for triplicate experiments. Solid bars, SW-13 cells; hatched bars, HeLa cells. Western analysis of transfected cell protein extracts was performed with anti-BRG-1 antiserum to demonstrate the level of protein expressed from pBJ5-BRG-1(K798R) and pBJ5-BRG-1 (bottom panel).