The endoplasmic reticulum-associated degradation of the epithelial sodium channel requires a unique complement of molecular chaperones.

ABSTRACT: The epithelial sodium channel (ENaC) is composed of a single copy of an alpha-, beta-, and gamma-subunit and plays an essential role in water and salt balance. Because ENaC assembles inefficiently after its insertion into the ER, a substantial percentage of each subunit is targeted for ER-associated degradation (ERAD). To define how the ENaC subunits are selected for degradation, we developed novel yeast expression systems for each ENaC subunit. Data from this analysis suggested that ENaC subunits display folding defects in more than one compartment and that subunit turnover might require a unique group of factors. Consistent with this hypothesis, yeast lacking the lumenal Hsp40s, Jem1 and Scj1, exhibited defects in ENaC degradation, whereas BiP function was dispensable. We also discovered

SUBMITTER: Buck TM 

PROVIDER: S-EPMC2836957 | biostudies-literature | 2010 Mar

REPOSITORIES: biostudies-literature