The gene was disrupted by replacement of a large part of the coding region with a PGK-neo cassette resulting in the deletion of the N-terminal multimerization domain. Northern blot analysis of brain RNA from homozygous mutant animals detected a truncated transcript, and Western blot analysis failed to detect the 85 kDa protein in the heart or brain. However, a 65 kDa protein was detected that may possibly be another channel protein that cross-reacts with the anti-Kcna4 antibody.