FIG. 5.

UBE2E3 affects ENaC activity. (A) Oocytes were injected either with ENaC cRNA alone or together with cRNA encoding wild-type UBE2E3 (UBE2E3 WT) or a catalytically inactive mutant of UBE2E3 (UBE2E3-CS). Amiloride-sensitive Na⁺ currents (I) were measured after 16 to 24 h. Values were normalized to control oocytes (H₂O) expressing ENaC alone (mean current of control, 1.56 ± 0.16 μA). After measurements, the oocytes were lysed, and the expression of UBE2E3 was checked by SDS-PAGE and Western blotting using an anti-UBE2E3 antibody. (B) Same as panel A, but increasing amounts (0, 2, 5, 10, and 20 ng) of UBE2E3-CS cRNA were injected with cRNA encoding ENaC (mean current of control, 1.59 ± 0.05 μA). (C) Oocytes were injected with ENaC cRNA either alone or in combination with mUbc4 cRNA or its inactive form mUbc4-CS (mean current of control, 1.53 ± 0.13 μA). All experiments show the results for 15 to 18 oocytes from three different animals per condition. Values that were significantly different from the control value (H₂O) are indicated as follows: *, P < 0.05; **, P < 0.01. Values that were not significantly different (NS) from each other are indicated.