Targeting PI3Kγ anchoring enhances CFTR membrane localization and modulator efficacy via PKD1.

Abstract

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.