Coexpression of Nedd4-2 decreases electrogenic peptide transport in PEPT1-expressing <i>Xenopus laevis</i> oocytes.

<p><b>A:</b> Representative original tracings showing I_gly-gly in <i>Xenopus laevis</i> oocytes injected with water (a), expressing PEPT1 alone (b) or with USP18 (c), Nedd4-2 (d), or with USP18 and Nedd4-2 (e). <b>B:</b> Arithmetic means ± SEM (n = 13–15) of I_gly-gly in <i>Xenopus laevis</i> oocytes injected with water (striped bar) or expressing PEPT1 without (white bar) or with USP18 (black bar), with Nedd4-2 (light grey bar), or with USP18 and Nedd4-2 (dark grey bar). *(p<0.05) indicates statistically significant difference from oocytes expressing PEPT1 alone.