A different pathway in the endoplasmic reticulum stress-induced expression of human HRD1 and SEL1 genes

Human HRD1 and SEL1 are components of endoplasmic reticulum-associated degradation (ERAD), which is a retrograde transport mechanism from the ER to the cytosol for removing unfolded proteins. The expression of HRD1 and SEL1 was induced by ER stress-inducing agents and overexpression of both ER stress-responsive transcription factors, ATF6 and XBP1. Inhibition of IRE1 and ATF6 revealed that ER stress-induced HRD1 and SEL1 expressions are mediated by IRE1-XBP1- and ATF6-dependent pathways, respectively. These results suggest that the ER stress-induced ERAD gene expressions are mediated by different pathways, which are attributed to the differences in the promoter regions. (c) 2007 Federation of European Biochemical Societies. Published by Elsevier B. V. All rights reserved.