ROLE OF THE I-SK PROTEIN IN THE I-MINK CHANNEL COMPLEX

The I-SK (also called minK) protein, although it is structurally unrel ated to any other ion channel subunit, induces slowly activating, volt age-dependent Kt channels (I-minK) in Xenopus oocytes or HEK293 cells. The quaternary structure of the I-minK channel complex has long remai ned a mystery, but recent studies suggest an interaction of the I-SK p rotein with a traditional K+ channel subunit, identified in man as K(V )LQT1. It is unclear at this point what the mechanism of this interact ion is, or whether the I-SK protein may also interact with other ion c hannel subunits. However, there is an abundance of information regardi ng the role and regulation of the I-SK protein in the I-minK channel c omplex, discussed in this review by Andreas Busch and Hartmut Suessbri ch. The I-SK protein is expressed in different tissues, where I-minK a ctivation may have distinct net effects on cell function. This fact ma kes I-minK an excellent target for pharmacological agents.