Format

Send to:

Choose Destination
See comment in PubMed Commons below
Mol Cell Biol. 2006 Nov;26(21):7999-8010. Epub 2006 Aug 28.

Luman/CREB3 induces transcription of the endoplasmic reticulum (ER) stress response protein Herp through an ER stress response element.

Author information

  • 1Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada N1G 2W1.

Abstract

Luman/CREB3 (also called LZIP) is an endoplasmic reticulum (ER) membrane-bound transcription factor which is believed to undergo regulated intramembrane proteolysis in response to cellular cues. We previously found that Luman activates transcription from the unfolded protein response element. Here we report the identification of Herp, a gene involved in ER stress-associated protein degradation (ERAD), as a direct target of Luman. We found that Luman was transcriptionally induced and proteolytically activated by the ER stress inducer thaspsigargin. Overexpression of Luman activated transcription of cellular Herp via ER stress response element II (ERSE-II; ATTGG-N-CCACG) in the promoter region. Mutagenesis studies and chromatin immunoprecipitation assays showed that Luman physically associates with the Herp promoter, specifically the second half-site (CCACG) of ERSE-II. Luman was also necessary for the full activation of Herp during the ER stress response, since Luman small interfering RNA knockdown or functional repression by a dominant negative mutant attenuated Herp gene expression. Like Herp, overexpression of Luman protected cells against ER stress-induced apoptosis. With Luman structurally similar to ATF6 but resembling XBP1 in DNA-binding specificities, we propose that Luman is a novel factor that plays a role in ERAD and a converging point for various signaling pathways channeling through the ER.

PMID:
16940180
[PubMed - indexed for MEDLINE]
PMCID:
PMC1636730
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Write to the Help Desk