| We identified an ER membrane associated ubiquitin ligase complex containing the E 3 RMA1 , the E 2 Ubc6e , and Derlin 1 that cooperates with the cytosolic Hsc70 / CHIP E 3 complex to triage CFTR and CFTR Delta F 508 . ^^^ Derlin 1 serves to retain CFTR in the ER membrane and interacts with RMA 1 and Ubc6e to promote CFTR ' s proteasomal degradation . ^^^ |