Targeting of ion channels to membrane microdomains: localization of KV channels to lipid rafts.

Voltage-gated K(+) channels are an important determinant of cellular excitability and key components of multiple signal transduction pathways. However, relatively little is known about the mechanisms of K(V) channel localization or their membrane partitioning. Lipid rafts are specialized membrane microdomains that are rich in sphingolipids and cholesterol. These rafts have been implicated in the organization of many membrane-associated signaling pathways and are currently the focus of intense interest in the scientific community. Biochemical and functional evidence indicate that K(V) channels, in addition to other ion channels, localize to lipid raft microdomains on the cell surface. Although several important questions regarding specific mechanisms of channel localization remain, emerging data indicate that protein-lipid interactions should be considered as a new mechanism of ion channel localization and compartmentation that might permit the therapeutic modulation of channel properties via alteration in membrane lipids.