KCNE2 (or MiRP1) is a member of a family of proteins that regulate the activity of voltage-dependent K+ channels. The other members of the family are KCNE1 (IsK, MiNK), KCNE3 (MiRP2), KCNE4 (MiRP3) and KCNE5 (MiRP4). KCNE1 is the founding member of the family and KCNE2 was discovered based on its homology with KCNE1.nThe KCNE regulatory subunits are small proteins (14- 20 kD) with a type-1 integral membrane topology. It is believed that both the cytoplasmic C-terminus tail and the transmembrane domain are necessary for the interaction with the a subunits. The stoichiometry of the KCNE subunits with their partner a subunits in the native channels is not clear and ratios ranging from 2 to 14 KCNE subunits per 4 a subunits have been proposed