Interactome of CFTR using Apex and TurboID proximity labelling

The proteins interacting with CFTR and its mutants have been intensively studied using different experimental approaches, enabling to better understand the cellular processes leading to proper protein folding, routing to the plasma membrane, recycling, activation and degradation. Recently, several strategies have been developed based on the proximity labelling of protein partners or proteins in close vicinity and their subsequent identification by mass spectrometry. In this study, we evaluate TurboID and APEX2 proximity labelling approaches on WT CFTR and compare results to those obtained by co-immunoprecipitation and in databases. We then compared the CFTR-WT interactome to two mutants of CFTR (G551D and W1282X) and the structurally unrelated potassium channel KCNK3. The two methods efficiently identified both known and novel CFTR protein partners and in proximity such as multiple SLC transporters. Hence proximity labelling approaches enable to obtain a wider picture of the CFTR interactome, feeding databases and giving a better understanding of the CFTR environment.