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.