Proper protein folding in the endoplasmic reticulum is required for attachment of a glycosylphosphatidylinositol anchor in plants
| Autor: | Ulrike Vavra, Richard Strasser, Yun-Ji Shin |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
0106 biological sciences
Signal peptide Protein Folding Glycosylphosphatidylinositols Physiology Arabidopsis Plant Science Endoplasmic-reticulum-associated protein degradation Endoplasmic Reticulum 01 natural sciences 03 medical and health sciences Genetics Research Articles Secretory pathway Glycoproteins 030304 developmental biology chemistry.chemical_classification 0303 health sciences Arabidopsis Proteins Endoplasmic reticulum ER retention Fusion protein Cell biology carbohydrates (lipids) chemistry lipids (amino acids peptides and proteins) Protein folding Glycoprotein 010606 plant biology & botany |
| Zdroj: | Plant Physiol |
| ISSN: | 1532-2548 0032-0889 |
| DOI: | 10.1093/plphys/kiab181 |
| Popis: | Endoplasmic reticulum (ER) quality control processes recognize and eliminate misfolded proteins to maintain cellular protein homeostasis and prevent the accumulation of defective proteins in the secretory pathway. Glycosylphosphatidylinositol (GPI)-anchored proteins carry a glycolipid modification, which provides an efficient ER export signal and potentially prevents the entry into ER-associated degradation (ERAD), which is one of the major pathways for clearance of terminally misfolded proteins from the ER. Here, we analyzed the degradation routes of different misfolded glycoproteins carrying a C-terminal GPI-attachment signal peptide in Arabidopsis thaliana. We found that a fusion protein consisting of the misfolded extracellular domain from Arabidopsis STRUBBELIG and the GPI-anchor attachment sequence of COBRA1 was efficiently targeted to hydroxymethylglutaryl reductase degradation protein 1 complex-mediated ERAD without the detectable attachment of a GPI anchor. Non-native variants of the GPI-anchored lipid transfer protein 1 (LTPG1) that lack a severely misfolded domain, on the other hand, are modified with a GPI anchor and targeted to the vacuole for degradation. Impaired processing of the GPI-anchoring signal peptide by mutation of the cleavage site or in a GPI-transamidase-compromised mutant caused ER retention and routed the non-native LTPG1 to ERAD. Collectively, these results indicate that for severely misfolded proteins, ER quality control processes are dominant over ER export. For less severely misfolded proteins, the GPI anchor provides an efficient ER export signal resulting in transport to the vacuole. |
| Databáze: | OpenAIRE |
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