Pathogenic mutation of UBQLN2 impairs its interaction with UBXD8 and disrupts endoplasmic reticulum-associated protein degradation.
Publication/Presentation Date
4-1-2014
Abstract
Protein aggregation is a common feature of several neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration. How protein aggregates are formed and contribute to neurodegeneration, however, is not clear. Mutation of Ubiquilin 2 (UBQLN2) has recently been linked to ALS and frontotemporal lobar degeneration. Therefore, we examined the effect of ALS-linked UBQLN2 mutation on endoplasmic reticulum-associated protein degradation (ERAD). Compared to its wild-type counterpart, mutated UBQLN2 caused greater accumulation of the ERAD substrate Hong Kong variant of α-1-antitrypsin, although ERAD was disturbed by both UBQLN2 over-expression and knockdown. Also, UBQLN2 interacted with ubiquitin regulatory X domain-containing protein 8 (UBXD8) in vitro and in vivo, and this interaction was impaired by pathogenic mutation of UBQLN2. As UBXD8 is an endoplasmic membrane protein involved in the translocation of ubiquitinated ERAD substrates, UBQLN2 likely cooperates with UBXD8 to transport defective proteins from the endoplasmic reticulum to the cytosol for degradation, and this cell-protective function is disturbed by pathogenic mutation of UBQLN2.
Volume
129
Issue
1
First Page
99
Last Page
106
ISSN
1471-4159
Published In/Presented At
Xia, Y., Yan, L. H., Huang, B., Liu, M., Liu, X., & Huang, C. (2014). Pathogenic mutation of UBQLN2 impairs its interaction with UBXD8 and disrupts endoplasmic reticulum-associated protein degradation. Journal of neurochemistry, 129(1), 99–106. https://doi.org/10.1111/jnc.12606
Disciplines
Medicine and Health Sciences
PubMedID
24215460
Department(s)
Department of Medicine
Document Type
Article