Characterization of erasin (UBXD2): a new ER protein that promotes ER-associated protein degradation
| Autor: | Corrine Peterhoff, Ralph A. Nixon, Chaobo Yin, Howard Doong, Mervyn J. Monteiro, Shengyun Fang, Jing Liang |
|---|---|
| Rok vydání: | 2006 |
| Předmět: |
Cytoplasm
Protein Denaturation Immunoprecipitation Valosin-containing protein Molecular Sequence Data Protein domain Cell Cycle Proteins macromolecular substances Protein Sorting Signals Protein degradation Biology Endoplasmic-reticulum-associated protein degradation Endoplasmic Reticulum Alzheimer Disease Stress Physiological Valosin Containing Protein Humans Tissue Distribution Amino Acid Sequence Cloning Molecular Integral membrane protein Cells Cultured Conserved Sequence Phylogeny Aged Adenosine Triphosphatases Sequence Homology Amino Acid Endoplasmic reticulum Membrane Proteins STIM1 Cell Biology Middle Aged Molecular biology Protein Structure Tertiary Cell biology biology.protein RNA Interference Autopsy HeLa Cells Protein Binding |
| Zdroj: | Journal of Cell Science. 119:4011-4024 |
| ISSN: | 1477-9137 0021-9533 |
| DOI: | 10.1242/jcs.03163 |
| Popis: | Ubiquitin regulator-X (UBX) is a discrete protein domain that binds p97/valosin-containing protein (VCP), a molecular chaperone involved in diverse cell processes, including endoplasmic-reticulum-associated protein degradation (ERAD). Here we characterize a human UBX-containing protein, UBXD2, that is highly conserved in mammals, which we have renamed erasin. Biochemical fractionation, immunofluorescence and electron microscopy, and protease protection experiments suggest that erasin is an integral membrane protein of the endoplasmic reticulum and nuclear envelope with both its N- and C-termini facing the cytoplasm or nucleoplasm. Localization of GFP-tagged deletion derivatives of erasin in HeLa cells revealed that a single 21-amino-acid sequence located near the C-terminus is necessary and sufficient for localization of erasin to the endoplasmic reticulum. Immunoprecipitation and GST-pulldown experiments confirmed that erasin binds p97/VCP via its UBX domain. Additional immunoprecipitation assays indicated that erasin exists in a complex with other p97/VCP-associated factors involved in ERAD. Overexpression of erasin enhanced the degradation of the ERAD substrate CD3δ, whereas siRNA-mediated reduction of erasin expression almost completely blocked ERAD. Erasin protein levels were increased by endoplasmic reticulum stress. Immunohistochemical staining of brain tissue from patients with Alzheimer's disease and control subjects revealed that erasin accumulates preferentially in neurons undergoing neurofibrillary degeneration in Alzheimer's disease. These results suggest that erasin may be involved in ERAD and in Alzheimer's disease. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|