M-type KCNQ2-KCNQ3 potassium channels are modulated by the KCNE2 subunit

KCNQ2 and KCNQ3 subunits belong to the six transmembrane domain K+ channel family and loss of function mutations are associated with benign familial n eonatal convulsions. KCNE2 (MirP1) is a single transmembrane domain subunit first described to be a modulator of the HERG potassium channel in the hea rt. Here, we show that KCNE2 is present in brain, in areas which also expre ss KCNQ2 and KCNQ3 channels, We demonstrate that KCNE2 associates with KCNQ 2 and/or KCNQ3 subunits, In transiently transfected COS cells, KCNE2 expres sion produces an acceleration of deactivation kinetics of KCNQ2 and of the KCNQ2-KCNQ3 complex. Effects of two previously identified arrhythmogenic mu tations of KCNE2 have also been analyzed. (C) 2000 Federation of European B iochemical Societies. Published by Elsevier Science B.V. All rights reserve d.