Biomaterial Database

Structural Insights into GIRK Channel Function. 2015

Ian W Glaaser, and Paul A Slesinger

Department of Neuroscience, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA.

G protein-gated inwardly rectifying potassium (GIRK; Kir3) channels, which are members of the large family of inwardly rectifying potassium channels (Kir1-Kir7), regulate excitability in the heart and brain. GIRK channels are activated following stimulation of G protein-coupled receptors that couple to the G(i/o) (pertussis toxin-sensitive) G proteins. GIRK channels, like all other Kir channels, possess an extrinsic mechanism of inward rectification involving intracellular Mg(2+) and polyamines that occlude the conduction pathway at membrane potentials positive to E(K). In the past 17 years, more than 20 high-resolution atomic structures containing GIRK channel cytoplasmic domains and transmembrane domains have been solved. These structures have provided valuable insights into the structural determinants of many of the properties common to all inward rectifiers, such as permeation and rectification, as well as revealing the structural bases for GIRK channel gating. In this chapter, we describe advances in our understanding of GIRK channel function based on recent high-resolution atomic structures of inwardly rectifying K(+) channels discussed in the context of classical structure-function experiments.

UI	MeSH Term	Description	Entries
D008564	Membrane Potentials	The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization).	Resting Potentials,Transmembrane Potentials,Delta Psi,Resting Membrane Potential,Transmembrane Electrical Potential Difference,Transmembrane Potential Difference,Difference, Transmembrane Potential,Differences, Transmembrane Potential,Membrane Potential,Membrane Potential, Resting,Membrane Potentials, Resting,Potential Difference, Transmembrane,Potential Differences, Transmembrane,Potential, Membrane,Potential, Resting,Potential, Transmembrane,Potentials, Membrane,Potentials, Resting,Potentials, Transmembrane,Resting Membrane Potentials,Resting Potential,Transmembrane Potential,Transmembrane Potential Differences
D011188	Potassium	An element in the alkali group of metals with an atomic symbol K, atomic number 19, and atomic weight 39.10. It is the chief cation in the intracellular fluid of muscle and other cells. Potassium ion is a strong electrolyte that plays a significant role in the regulation of fluid volume and maintenance of the WATER-ELECTROLYTE BALANCE.
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D051676	G Protein-Coupled Inwardly-Rectifying Potassium Channels	A family of inwardly-rectifying potassium channels that are activated by PERTUSSIS TOXIN sensitive G-PROTEIN-COUPLED RECEPTORS. GIRK potassium channels are primarily activated by the complex of GTP-BINDING PROTEIN BETA SUBUNITS and GTP-BINDING PROTEIN GAMMA SUBUNITS.	G Protein-Activated Potassium Channels,G Protein-Coupled Inwardly-Rectifying Potassium Channel 1,G Protein-Coupled Inwardly-Rectifying Potassium Channel 2,G Protein-Coupled Inwardly-Rectifying Potassium Channel 3,G Protein-Coupled Inwardly-Rectifying Potassium Channel 4,GIRK Potassium Channels,GIRK1 Potassium Channel,GIRK2 Potassium Channel,GIRK3 Potassium Channel,GIRK4 Potassium Channel,Kir3 Potassium Channels,Kir3.1 Potassium Channel,Kir3.2 Potassium Channel,Kir3.3 Potassium Channel,Kir3.4 Potassium Channel,G Protein Activated Potassium Channels,G Protein Coupled Inwardly Rectifying Potassium Channel 1,G Protein Coupled Inwardly Rectifying Potassium Channel 2,G Protein Coupled Inwardly Rectifying Potassium Channel 3,G Protein Coupled Inwardly Rectifying Potassium Channel 4,G Protein Coupled Inwardly Rectifying Potassium Channels,Potassium Channel, GIRK1,Potassium Channel, GIRK2,Potassium Channel, GIRK3,Potassium Channel, GIRK4,Potassium Channel, Kir3.1,Potassium Channel, Kir3.2,Potassium Channel, Kir3.3,Potassium Channel, Kir3.4,Potassium Channels, GIRK,Potassium Channels, Kir3