the-aps.org>meetings>eb

Lipid Mediated Regulation of Membrane Transport

Membrane transport proteins are by definition integral proteins that span the lipid bilayer.  These ion channels and transporters are invariably regulated by intracellular second messenger systems.  The classical thought is that these proteins are passively embedded in a homogenous lipid bilayer and that these second messenger cascades are responsible for their dynamic regulation.  Such conventional wisdom has been recently challenged by novel findings indicating that lipid membranes contain microdomains defined as lipid rafts.  These raft domains are enriched in various lipids (e.g., cholesterol) and proteins (e.g., flotillin).  These domains allow the enrichment of channels and transports, along with signaling molecules.  Moreover, these domains exhibit different biophysical properties than the bulk membrane, including different membrane stiffness, order, and thickness.  These differences can alter the activity of embedded channels and transporters, and provide new modes of dynamically regulating these important processes. The exciting compendium of presentations will span the spectrum of regulation of native channels by the membrane environment and membrane lipids; via changes of the bulk bilayer properties or by raft residency; to regulation of channels in artificial lipid bilayers.  These talks will provide a timely account of the various mechanisms by which the lipid bilayer can affect channel and transporter function.