Details

Autor(en) / Beteiligte

• You, Hui
• Ge, Yamei
• Zhang, Jian
• Cao, Yizhi
• Xing, Jing
• Su, Dongming
• Huang, Yujie
• Li, Min
• Qu, Shen
• Sun, Fei
• Liang, Xiubin

Titel

Derlin-1 promotes ubiquitylation and degradation of the epithelial Na + channel, ENaC

Ist Teil von

• Journal of cell science, 2017-03, Vol.130 (6), p.1027-1036

Ort / Verlag

England: The Company of Biologists Ltd

Erscheinungsjahr

2017

Quelle

MEDLINE

Beschreibungen/Notizen

• Ubiquitylation of the epithelial Na channel (ENaC) plays a critical role in cellular functions, including transmembrane transport of Na , Na and water balance, and blood pressure stabilization. Published studies have suggested that ENaC subunits are targets of ER-related degradation (ERAD) in yeast systems. However, the molecular mechanism underlying proteasome-mediated degradation of ENaC subunits remains to be established. Derlin-1, an E3 ligase mediator, links recognized target proteins to ubiquitin-mediated proteasomal degradation in the cytosol. In the present study, we found that derlin-1 suppressed the expression of ENaC at the protein level and that the subunit α-ENaC (also known as SCNN1A) physically interacted with derlin-1 at the membrane-anchored domains or the loop regions, and that derlin-1 initiated α-ENaC retrotranslocation. In addition, HUWE1, an endoplasmic reticulum (ER)-resident E3 ubiquitin ligase, was recruited and promoted K11-linked polyubiquitylation of α-ENaC and, hence, formation of an α-ENaC ubiquitin-mediated degradation complex. These findings suggest that derlin-1 promotes ENaC ubiquitylation and enhances ENaC ubiquitin- mediated proteasome degradation. The derlin-1 pathway therefore may represent a significant early checkpoint in the recognition and degradation of ENaC in mammalian cells.