A vacuolar carboxypeptidase mutant of Arabidopsis thaliana is degraded by the ERAD pathway independently of its N-glycan
- Department of Chemistry, Graduate School of Science, Nagoya University, Chikusa-ku, Nagoya 464-8602 (Japan)
Misfolded proteins produced in the endoplasmic reticulum (ER) are degraded by a mechanism, the ER-associated degradation (ERAD). Here we report establishment of the experimental system to analyze the ERAD in plant cells. Carboxypeptidase Y (CPY) is a vacuolar enzyme and its mutant CPY* is degraded by the ERAD in yeast. Since Arabidopsis thaliana has AtCPY, an ortholog of yeast CPY, we constructed and expressed fusion proteins consisting of AtCPY and GFP and of AtCPY*, which carries a mutation homologous to yeast CPY*, and GFP in A. thaliana cells. While AtCPY-GFP was efficiently transported to the vacuole, AtCPY*-GFP was retained in the ER to be degraded in proteasome- and Cdc48-dependent manners. We also found that AtCPY*-GFP was degraded by the ERAD in yeast cells, but that its single N-glycan did not function as a degradation signal in yeast or plant cells. Therefore, AtCPY*-GFP can be used as a marker protein to analyze the ERAD pathway, likely for nonglycosylated substrates, in plant cells.
- OSTI ID:
- 22202402
- Journal Information:
- Biochemical and Biophysical Research Communications, Journal Name: Biochemical and Biophysical Research Communications Journal Issue: 3 Vol. 393; ISSN BBRCA9; ISSN 0006-291X
- Country of Publication:
- United States
- Language:
- English
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