Activation of ATF6 and an ATF6 DNA binding site by the endoplasmic reticulum stress response.
ATF6 is a member of the basic-leucine zipper family of transcription factors. It contains a transmembrane domain and is located in membranes of the endoplasmic reticulum. ATF6 has been implicated in the endoplasmic reticulum (ER) stress response pathway since it can activate expression of GRP78 and other genes induced by the ER stress response. ER stress appears to activate ATF6 by cleavage from the ER membrane and translocation to the nucleus. However, direct DNA binding by ATF6 had not been demonstrated. In this report, we have identified a consensus DNA binding sequence for ATF6. This site is related to but distinct from ATF1/CREB binding sites. The site was placed in a reporter gene and was specifically activated by ATF6 overexpression and was strongly induced by the ER stress response. A dominant negative form of ATF6 blocked ER stress induction of both ATF6 site and GRP78 reporter genes. We further found that GAL4-ATF6 could be activated by ER stress. These results demonstrate that ATF6 is a direct target of the ER stress response. A proximal sensor of the ER stress response, human IRE1 (hIRE1), was sufficient to activate the ATF6 reporter gene, while a dominant negative form of hIRE1 blocked ER stress activation, suggesting that hIRE1 is upstream of ATF6 in the ER stress signaling pathway.
Wang
Y
Y
Department of Biological Sciences, Columbia University, New York, New York 10027, USA.
Shen
J
J
Arenzana
N
N
Tirasophon
W
W
Kaufman
R J
RJ
Prywes
R
R
D051702:Activating Transcription Factor 6; D001483:Base Sequence; D001665:Binding Sites; D002352:Carrier Proteins / Q000235:genetics; D004247:DNA / Q000737:chemistry / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000096:biosynthesis / Q000378:metabolism*; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D000091342:Endoplasmic Reticulum Chaperone BiP; D006367:HeLa Cells; D006360:Heat-Shock Proteins; D006801:Humans; D018832:Molecular Chaperones / Q000235:genetics; D018384:Oxidative Stress; D014157:Transcription Factors / Q000096:biosynthesis / Q000378:metabolism*; D014415:Tunicamycin / Q000494:pharmacology
C497111:ATF6 protein, human; D051702:Activating Transcription Factor 6; D002352:Carrier Proteins; D004268:DNA-Binding Proteins; D000091342:Endoplasmic Reticulum Chaperone BiP; C000717247:HSPA5 protein, human; D006360:Heat-Shock Proteins; D018832:Molecular Chaperones; D014157:Transcription Factors; D014415:Tunicamycin; D004247:DNA