Figure 3.

Calreticulin gain of function is sufficient to alleviate ER stress. A and B, overexpression of calreticulin decreased GRP78 levels in HeLa cells treated with tunicamycin (A) or thapsigargin (B). HeLa cells were transfected with gradient amounts of myc-CRT or pcDNA as a control and then treated with vehicle (DMSO), tunicamycin (2 μg/ml), or thapsigargin (300 nm) for 16 h and lysed for immunoblotting. GAPDH was used as a loading control. Densitometric quantification for expression of GRP78 was normalized to GAPDH protein levels in cell lysates.