Mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene, which encodes a cAMP-activated chloride channel, cause cystic fibrosis (CF), the most common life-threatening inherited disorder among White individuals. Current CFTR correctors and potentiators, such as elexacaftor-tezacaftor-ivacaftor (ETI), only partially restore the function of the most prevalent mutant, F508del-CFTR, resulting in residual disease in people with CF. Here, we demonstrate that a mimetic peptide targeting the A-kinase-anchoring protein (AKAP) function of PI3Kγ (PI3Kγ MP), and driving localized cAMP elevation, enhances F508del-CFTR membrane localization, maximizing ETI efficacy in restoring chloride secretion. Mechanistically, PI3Kγ MP activates an AKAP-Lbc-anchored pool of PKD1, a known regulator of membrane trafficking. Consistently, PKD1 inhibition prevents PI3Kγ MP from enhancing the membrane expression of ETI-corrected F508del-CFTR. Overall, our findings reveal a regulatory pathway controlling CFTR membrane abundance via the AKAP function of PI3Kγ, which can be targeted to overcome the limitations of current CFTR modulator therapies.
Murabito et al. (Mon,) studied this question.