FIG. 3.

Western blot analysis of Irr expression under nonreducing conditions. Anti-IRR staining reveals a specific band at ∼350 kDa corresponding to the heterotetrameric IRR visible in WT and Irr^+/− kidney samples but not in Irr^−/− mice, indicating that the Irr mutant mice carry a bona fide gene knockout. No signal was detected in the negative control (liver, lane L). The positive control used was a protein extract from 293 cells expressing IRR (IRR-293).