FIGURE 4.

Expression of bestrophins in different human airway epithelial cell lines. Shown are the results from RT-PCR analysis (with (+) and without (−) reverse transcriptase) of the four human isoforms of bestrophin (BEST1–4) in four different human airway epithelial cell lines (left panels). Whole cell conductances were measured before and after stimulation of airway epithelial cells by 100 μm ATP in the presence of the K⁺ channel blockers Ba²⁺ (5 mm) and tetraethylammonium (TEA; 10 mm) (right panels). ATP activated a whole cell current only in respiratory cell lines that express BEST1. The asterisks indicate significant difference compared with the control (paired Student's t test). n.s. indicates no significant changes upon ATP stimulation. The number of experiments is indicated in parentheses. nS, nanosiemens.