The invention provides isolated nucleic acids molecules, designated 52906, 33408, or 12189 nucleic acid molecules, which encode novel potassium channel members. The invention also provides antisense nucleic acid molecules, recombinant expression vectors containing 52906, 33408, or 12189 nucleic acid molecules, host cells into which the expression vectors have been introduced, and nonhuman transgenic animals in which a 52906, 33408, or 12189 gene has been introduced or disrupted. The invention still further provides isolated 52906, 33408, or 12189 proteins, fusion proteins, antigenic peptides and anti-52906, 33408, or 12189 antibodies. Diagnostic methods utilizing compositions of the invention are also provided.