RNF5 and RNF185 ubiquitinate misfolded CFTR as part of the retrotranslocon that targets the receptor for degradation through the ERAD pathway. Both depletion of the E3 ligases by siRNA and expression of a catalytically inactive form of the enzyme strongly inhibits CFTR degradation (El Khouri et al, 2013; Younger et al, 2006).
El Khouri, E,
Le Pavec, G,
ubiquitin protein ligase activity of misfolded CFTR:ERAD complex [endoplasmic reticulum membrane]