Structural highlights
Function
[IRK2_MOUSE] Probably participates in establishing action potential waveform and excitability of neuronal and muscle tissues. Inward rectifier potassium channels are characterized by a greater tendency to allow potassium to flow into the cell rather than out of it. Their voltage dependence is regulated by the concentration of extracellular potassium; as external potassium is raised, the voltage range of the channel opening shifts to more positive voltages. The inward rectification is mainly due to the blockage of outward current by internal magnesium. Can be blocked by extracellular barium and cesium.
Publication Abstract from PubMed
The interaction of the extra-membranous domain of tetrameric inwardly rectifying Kir2.1 ion channels (Kir2.1NC(4)) with the membrane associated guanylate kinase protein PSD-95 has been studied using Transmission Electron Microscopy in negative stain. Three types of complexes were observed in electron micrographs corresponding to a 1:1 complex, a large self-enclosed tetrad complex and extended chains of linked channel domains. Using models derived from small angle X-ray scattering experiments in which high resolution structures from X-ray crystallographic and Nuclear Magnetic Resonance studies are positioned, the envelopes from single particle analysis can be resolved as a Kir2.1NC(4):PSD-95 complex and a tetrad of this unit (Kir2.1NC(4):PSD-95)(4). The tetrad complex shows the close association of the Kir2.1 cytoplasmic domains and the influence of PSD-95 mediated self-assembly on the clustering of these channels.
Self-directed assembly and clustering of the cytoplasmic domains of inwardly rectifying Kir2.1 potassium channels on association with PSD-95.,Fomina S, Howard TD, Sleator OK, Golovanova M, O'Ryan L, Leyland ML, Grossmann JG, Collins RF, Prince SM Biochim Biophys Acta. 2011 Jul 5;1808(10):2374-2389. PMID:21756874[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Fomina S, Howard TD, Sleator OK, Golovanova M, O'Ryan L, Leyland ML, Grossmann JG, Collins RF, Prince SM. Self-directed assembly and clustering of the cytoplasmic domains of inwardly rectifying Kir2.1 potassium channels on association with PSD-95. Biochim Biophys Acta. 2011 Jul 5;1808(10):2374-2389. PMID:21756874 doi:10.1016/j.bbamem.2011.06.021
