Fig. 5.

Functional expression of Aqp1a in Xenopus oocytes. A: Western blot. Oocytes injected with aqp1a cRNA or H₂O were incubated at 18°C for 4–5 days. Membrane proteins (10 μg per lane) from these oocytes were separated by SDS-PAGE and prepared for Western blot analysis. The expression of Aqp1a protein was examined with an antibody directed against European eel AQP1. B: water permeability of oocytes injected with H₂O or aqp1a cRNA. Values are expressed as means ± SE, with numbers of oocytes in parentheses. The P value is indicated. C: inhibition of water permeability of Xenopus oocytes expressing Aqp1a by pCMBS, and reversibility of the inhibitory effect of p-chloromercuribenzene sulfonate (pCMBS) by β-mercaptoethanol (BME). The three bars represent, untreated oocytes expressing aqp1a (solid bar), aqp1a-expressing oocytes treated with 1 mM pCMBS 20 min (open hatched bar), and aqp1a-expressing oocytes treated with pCMBS and then with 5 mM β-mercaptoethanol for 5 min (solid hatched bar).