Intracellular hemin is a potent inhibitor of the voltage-gated potassium channel Kv10.1.

Heme, an iron-protoporphyrin IX complex, is a cofactor bound to various hemoproteins and supports a broad range of functions, such as electron transfer, oxygen transport, signal transduction, and drug metabolism. In recent years, there has been a growing recognition of heme as a non-genomic modulator of ion channel functions. Here, we show that intracellular free heme and hemin modulate human ether à go-go (hEAG1, Kv10.

Impact of intracellular hemin on N-type inactivation of voltage-gated K channels.

N-type inactivation of voltage-gated K channels is conferred by the N-terminal "ball" domains of select pore-forming α subunits or of auxiliary β subunits, and influences electrical cellular excitability. Here, we show that hemin impairs inactivation of K channels formed by Kv3.4 α subunits as well as that induced by the subunits Kvβ1.