Skip to main content
. 2015 Oct;185(10):2790–2804. doi: 10.1016/j.ajpath.2015.06.007

Figure 5.

Figure 5

Signaling via a NO-cGMP pathway in the microdomains of CFTR-iNOS protein complex potentiates CFTR channel function. A: Representative pseudocolor images of CFP/FRET emission ratio before (time, 0) and after adding 250 μmol/L zaprinast (time, 10 minutes) in HEK-293 cells transiently expressing membrane-bound cGMP sensor m-cygnet 2.1 and transfected with pCDNA3 empty vector or pcDNA3-iNOS. Representative line graph shows the changes of CFP/FRET emission ratio over time on adding the agonist. B: Averaged representative traces of CFTR-mediated I− influx in HEK-293-S (scrambled siRNA) and HEK-293-N (NHERF2 siRNA) cells that overexpress FLAG-WT-CFTR and iNOS in response to 250 μmol/L zaprinast. Bar graph represents baseline and zaprinast-induced CFP/FRET emission ratio in empty vector versus iNOS-transfected cells (A) and the rate of change in YFP fluorescence intensity indicative of the rate of chloride influx (B). Data are expressed as means ± SEM. n = 3 (A); n = 6 (B). ∗P < 0.05, ∗∗P < 0.01 determined with t-test. CFP, cyan fluorescent protein; CFTR, cystic fibrosis transmembrane-conductance regulator; FRET, fluorescence resonance energy transfer; iNOS, inducible nitric oxide synthase; NHERF2, Na+/H+ exchanger regulatory factor 2; NO, nitric oxide; PAR, cells with no FLAG-WT-CFTR and iNOS; WT, wild-type; YFP, yellow fluorescent protein.