The K+ voltage-gated channel subfamily E member (KCNE) family is a group of small, non-conducting, single transmembrane domain proteins that associate with pore-forming potassium channel subunits to form mixed complexes with unique characteristics.nFive different KCNE proteins have been described (KCNE1-5)2. The 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 α subunits