A time-dependent phase shift in the mammalian unfolded protein response
- PMID: 12586069
- DOI: 10.1016/s1534-5807(03)00022-4
A time-dependent phase shift in the mammalian unfolded protein response
Abstract
Unfolded or misfolded proteins in the endoplasmic reticulum (ER) must be refolded or degraded to maintain homeostasis of the ER. The ATF6 and IRE1-XBP1 pathways are important for the refolding process in mammalian cells; activation of these transcriptional programs culminates in induction of ER-localized molecular chaperones and folding enzymes. We show here that degradation of misfolded glycoprotein substrates requires transcriptional induction of EDEM (ER degradation-enhancing alpha-mannosidase-like protein), and that this is mediated specifically by IRE1-XBP1 and not by ATF6. As XBP1 is produced after ATF6 activation, our results reveal a time-dependent transition in the mammalian unfolded protein response: an ATF6-mediated unidirectional phase (refolding only) is followed by an XBP1-mediated bidirectional phase (refolding plus degradation) as the response progresses.
Comment in
-
IRE1: a role in UPREgulation of ER degradation.Dev Cell. 2003 Feb;4(2):144-6. doi: 10.1016/s1534-5807(03)00032-7. Dev Cell. 2003. PMID: 12586055 Review.
Publication types
MeSH terms
Substances
Grants and funding
LinkOut - more resources
Full Text Sources
Other Literature Sources
Research Materials
