Title: Structural and functional characterization of Kv6.2 a new gamma-subunit of voltage-gated potassium channel.

Authors: X R Zhu, R Netzer, K Böhlke, Q Liu, O Pongs

Journal, date & volume: Recept. Channels, 1999 , 6, 337-50

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/10551266

Abstract
We have cloned and functionally expressed Kv6.2, a new member of the Kv6 subfamily of voltage-gated potassium channel subunits. The human Kv6.2 (KCNF2) gene was mapped at 18q22-18q23. Kv6.2 mRNA is preferentially expressed in rat and human myocard. Rat and human Kv6.2 subunits appear to be unable to form functional Kv channels in a heterologous expression system, but, when coexpressed with Kv2.1 alpha subunits, heteromultimeric Kv channels were formed mediating voltage-activated delayed-rectifier type outward currents. Their kinetics and conductance-voltage relationship were different from those mediated by homomultimeric Kv2.1 channels. Yeast two-hybrid reporter assays indicated that Kv6.2 amino-termini are able to interact specifically with the Kv2.1 amino-terminus. It is proposed that this protein protein interaction underlies Kv2.1/Kv6.2 subunit assembly and the expression of functional heteromultimeric Kv2.1/Kv6.2 channels. The most resiliant feature of the Kv2.1/Kv6.2 channels was their submicromolar sensitivity to the antiarrhythmic drug propafenone. The data suggest that delayed-rectifier type channels containing Kv6.2 subunits may contribute to cardiac action potential repolarization.