Identification of the cis-Acting Endoplasmic Reticulum Stress Response Element Responsible for Transcriptional Induction of Mammalian Glucose-regulated Proteins

doi:10.1074/jbc.273.50.33741

Identification of the cis-Acting Endoplasmic Reticulum Stress Response Element Responsible for Transcriptional Induction of Mammalian Glucose-regulated Proteins

INVOLVEMENT OF BASIC LEUCINE ZIPPER TRANSCRIPTION FACTORS*

From HSP Research Institute, Kyoto Research Park, Kyoto 600-8813, Japan

Abstract

When unfolded proteins accumulate in the endoplasmic reticulum (ER), transcription of glucose-regulated proteins (GRPs) representing ER-resident molecular chaperones is markedly induced via the unfolded protein response (UPR) pathway. In contrast to recent progress in the analysis of yeast UPR, bothcis-acting elements and transactivators responsible for mammalian UPR have remained obscure. Here, we analyzed the promoter regions of human GRP78, GRP94, and calreticulin genes and identified a novel element designated the ER stress response element (ERSE). ERSE, with a consensus of CCAATN₉CCACG, was shown to be necessary and sufficient for induction of these GRPs. Using yeast one-hybrid screening, we isolated a human cDNA encoding a basic leucine zipper (bZIP) protein, ATF6, as a putative ERSE-binding protein. When overexpressed in HeLa cells, ATF6 enhanced transcription of GRP genes in an ERSE-dependent manner, whereas CREB-RP, another bZIP protein closely related to ATF6, specifically inhibited GRP induction. Endogenous ATF6 constitutively expressed as a 90-kDa protein was converted to a 50-kDa protein in ER-stressed cells, which appeared to be important for the cellular response to ER stress. These results suggest that, as in yeast, bZIP proteins are involved in mammalian UPR, acting through newly defined ERSE.

Footnotes

↵* The costs of publication of this article were defrayed in part by the payment of page charges. The article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
↵‡ To whom correspondence should be addressed. Tel.: 81-75-315-8656; Fax: 81-75-315-8659; E-mail: kazumori{at}hsp.co.jp.
↵2 S. Kaneda, T. Yura, and H. Yanagi, unpublished data.
↵3 B. Roy and A. S. Lee, personal communication.
↵4 K. Haze, H. Yoshida, H. Yanagi, T. Yura, and K. Mori, unpublished data.
↵5 M. Niwa-Rosen and P. Walter, personal communication.
Abbreviations:

GRP

glucose-regulated protein

ER

endoplasmic reticulum

ERSE

ER stress response element

UPR

unfolded protein response

UPRE

unfolded protein response element

GAL4AD

transactivation domain of GAL4 protein

TM

tunicamycin

SRF

serum response factor

SRE

serum response element

bZIP

basic leucine zipper

bp

base pair(s)

CREB

cAMP response element-binding protein

CREB-RP

CREB-related protein.
- Received July 6, 1998.
- Revision received September 22, 1998.
The American Society for Biochemistry and Molecular Biology, Inc.