Role of the ISK protein in the IminK channel complex.

Abstract The I SK (also called minK) protein, although it is structurally unrelated to any other ion channel subunit, induces slowly activating, voltage-dependent K + channels (I minK ) in Xenopus oocytes or HEK293 cells. The quaternary structure of the I minK channel complex has long remained a mystery but recent studies suggest an interaction of the I SK protein with a traditional K + channel subunit, identified in man as K V LQT1. It is unclear at this point what the mechanism of this interaction is, or whether the I SK protein may also interact with other ion channel subunits. However, there is an abundance of information regarding the role and regulation of the I SK protein in the I minK channel complex, discussed in this review by Andreas Busch and Hartmut Suessbrich . The I SK protein is expressed in different tissues, where I minK activation may have distinct net effects on cell function. This fact makes I minK an excellent target for pharmacological agents.