title: Oligomerization at the membrane: potassium channel structure and function.
abstract: Cell membranes present a naturally impervious barrier to aqueous solutes, such that the physiochemical environment on either side of the lipid bilayer can substantially differ. Integral membrane proteins are embedded in this heterogeneous lipid environment, wherein the juxtaposition of apolar and polar molecular surfaces defines factors such as transverse orientation, the surface area available for oligomerisation and the symmetry of resultant assemblies. This chapter focuses on potassium channels -representative molecular pores that play a critical role in electrical signalling by enabling selective transport of K(+) ions across cell membranes. Oligomerization is central to K(+) channel action; individual subunits are nonfunctional and conduction, selectivity and gating involve manipulation of the common subunit interface of the tetramer. Regulation of channel activity can be viewed from the perspective that the pore of K(+) channels has coopted other proteins, utilizing a process of hetero-oligomerisation to absorb new functions that both enable the pore to respond to extrinsic signals and provide an electrical signature.
authors.affiliation: The Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria, Australia.
authors.forename: Oliver B
authors.initials: OB
authors.lastname: Clarke
authors.forename: Jacqueline M
authors.initials: JM
authors.lastname: Gulbis
mesh_terms: D000596:Amino Acids / Q000737:chemistry; D002462:Cell Membrane / Q000502:physiology*; D006801:Humans; D015640:Ion Channel Gating / Q000502:physiology*; D008564:Membrane Potentials; D008958:Models, Molecular; D011188:Potassium / Q000378:metabolism*; D015221:Potassium Channels / Q000737:chemistry* / Q000378:metabolism; D011485:Protein Binding; D055503:Protein Multimerization; D017434:Protein Structure, Tertiary; D021122:Protein Subunits / Q000737:chemistry / Q000378:metabolism
chemical_list: D000596:Amino Acids; D015221:Potassium Channels; D021122:Protein Subunits; D011188:Potassium