Fig 4. TMH1,7 mutant P-gp fails to transport most of the fluorescent substrates tested.

WT and TMH1,7 mutant P-gp were expressed in HeLa cells by the BacMam baculovirus-based transduction system and 25 fluorescent substrates were used to determine their transport function. The efflux by WT P-gp (calculated as the value obtained after subtracting the mean fluorescence intensity of WT from untransduced cells) was taken as 100% and the efflux of indicated substrates by TMH1,7 mutant P-gp was calculated. The mean values from three to five independent experiments are shown and the error bars depict SD. The low level (<30%) was considered as no transport (solid line separating the two groups of substrates; see S1 Table for the level of transport of tested substrates by TMH1,7 mutant P-gp).