Ring Finger Protein 5 (RNF5)

E3 ubiquitin-protein ligase RNF5 contains a RING finger, which is a motif known to be involved in protein-protein interactions. This protein is a membrane-bound ubiquitin ligase. It can regulate cell motility by targeting paxillin ubiquitination and altering the distribution and localization of paxillin in cytoplasm and cell focal adhesions.

Derlin-1 retained CFTR in the ER membrane and interacted with RMA1 and UBC6E to promote proteasomal degradation of CFTR. RMA1 could recognize folding defects in delF508 coincident with translation, whereas CHIP appeared to act posttranslationally. A folding defect in delF508 detected by RMA1 involved the inability of the second membrane-spanning domain of CFTR to productively interact with N-terminal domains.