TY - JOUR
T1 - Conserved endoplasmic reticulum-associated degradation system to eliminate mutated receptor-like kinases in Arabidopsis
AU - Su, Wei
AU - Liu, Yidan
AU - Xia, Yang
AU - Hong, Zhi
AU - Li, Jianming
N1 - Funding information:
We are grateful to the Arabidopsis Biological Resource Center at Ohio State University for supplying cDNA/genomic clones and T-DNA insertional mutants of EBS5, AtSel1B, and the two Arabidopsis Hrd1 homologs; F. Tax for seeds of bri1–9 (Ws-2) and bri1–5; J. Chory (Salk Institute for Biological Studies, La Jolla, CA) for anti-BRI1 antibody; Y. Yin for anti-BES1 antibody; R. Boston for anti-maize CRT serum; A. Chang (University of Michigan) for the yeast Δhrd1 strain and the CPY* plasmid; and T. Tzfira for the pSITE03-RFP-HDEL plasmid. We thank members of the J.L. laboratory for helpful discussions. This work was supported by National Institutes of Health Grant GM060519 (to J.L.).
PY - 2011/1/11
Y1 - 2011/1/11
N2 - Endoplasmic reticulum (ER)-associated degradation (ERAD) is an integral part of the ER quality-control system that removes toxic misfolded proteins via ubiquitin/proteasome-mediated degradation. Most of our knowledge on ERAD comes from biochemical and genetic studies in yeast and mammalian cells. Although ERAD is known to operate in plant cells, little is known about its molecular components and its biochemical mechanism. A genetic screen for suppressors of the Arabidopsis bri1-9, a weak dwarf mutant caused by ER retention of a structurally defective yet biochemically competent brassinosteroid (BR) receptor BRI1, resulted in identification of the EMS-mutagenized bri1 suppressor 5 (EBS5) gene that encodes an Arabidopsis homolog of the yeast Hrd3/mammlian Sel1L protein known to be involved in ERAD. Loss-of-function ebs5 mutations block the ERAD of bri1-9 and bri1-5, another ER-retained BR receptor. We showed that EBS5 complemented the ERAD defect of the yeast Δhrd3 mutant and interacted with the two mutated BR receptors in plant cells. Using a reverse genetic approach, we discovered that two Arabidopsis homologs of the yeast/mammalian Hrd1, an ER membrane-localized ubiquitin ligase, function redundantly in the ERAD of bri1-9. Together, our results revealed functional roles of two conserved ERAD components in degrading mutated/misfolded receptor-like kinases in Arabidopsis.
AB - Endoplasmic reticulum (ER)-associated degradation (ERAD) is an integral part of the ER quality-control system that removes toxic misfolded proteins via ubiquitin/proteasome-mediated degradation. Most of our knowledge on ERAD comes from biochemical and genetic studies in yeast and mammalian cells. Although ERAD is known to operate in plant cells, little is known about its molecular components and its biochemical mechanism. A genetic screen for suppressors of the Arabidopsis bri1-9, a weak dwarf mutant caused by ER retention of a structurally defective yet biochemically competent brassinosteroid (BR) receptor BRI1, resulted in identification of the EMS-mutagenized bri1 suppressor 5 (EBS5) gene that encodes an Arabidopsis homolog of the yeast Hrd3/mammlian Sel1L protein known to be involved in ERAD. Loss-of-function ebs5 mutations block the ERAD of bri1-9 and bri1-5, another ER-retained BR receptor. We showed that EBS5 complemented the ERAD defect of the yeast Δhrd3 mutant and interacted with the two mutated BR receptors in plant cells. Using a reverse genetic approach, we discovered that two Arabidopsis homologs of the yeast/mammalian Hrd1, an ER membrane-localized ubiquitin ligase, function redundantly in the ERAD of bri1-9. Together, our results revealed functional roles of two conserved ERAD components in degrading mutated/misfolded receptor-like kinases in Arabidopsis.
KW - E3 ligase
KW - Endoplasmic reticulum-associated degradation substrate-recruiting factor
KW - Plant steroid receptor
KW - Unfolded protein response
UR - http://www.scopus.com/inward/record.url?scp=79551670516&partnerID=8YFLogxK
U2 - 10.1073/pnas.1013251108
DO - 10.1073/pnas.1013251108
M3 - Journal article
C2 - 21187394
AN - SCOPUS:79551670516
SN - 0027-8424
VL - 108
SP - 870
EP - 875
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 2
ER -