Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2005-11-29
pubmed:abstractText
A major role for Müller cells in the retina is to buffer changes in the extracellular K+ concentration ([K+]o) resulting from light-evoked neuronal activity. The primary K+ conductance in Müller cells is the inwardly rectifying K+ channel Kir4.1. Since this channel is constitutively active, K+ can enter or exit Müller cells depending on the state of the [K+]o. This process of [K+]o buffering by Müller cells ("K+ siphoning") is enhanced by the precise accumulation of these K+ channels at discrete subdomains of Müller cell membranes. Specifically, Kir4.1 is localized to the perivascular processes of Müller cells in animals with vascular retinas and to the endfeet of Müller cells in all species examined. The water channel aquaporin-4 (AQP4) also appears to be important for [K+]o buffering and is expressed in Müller cells in a very similar subcellular distribution pattern to that of Kir4.1. To gain a better understanding of how Müller cells selectively target K+ and water channels to discrete membrane subdomains, we addressed the question of whether Kir4.1 and AQP4 associate with the dystrophin-glycoprotein complex (DGC) in the mammalian retina. Immunoprecipitation (IP) experiments were utilized to show that Kir4.1 and AQP4 are associated with DGC proteins in rat retina. Furthermore, AQP4 was also shown to co-precipitate with Kir4.1, suggesting that both channels are tethered together by the DGC in Müller cells. This work further defines a subcellular localization mechanism in Müller cells that facilitates [K+]o buffering in the retina.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Aquaporin 4, http://linkedlifedata.com/resource/pubmed/chemical/Calcium-Binding Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Cross-Linking Reagents, http://linkedlifedata.com/resource/pubmed/chemical/Dystrophin, http://linkedlifedata.com/resource/pubmed/chemical/Dystrophin-Associated Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Excitatory Amino Acid Transporter 1, http://linkedlifedata.com/resource/pubmed/chemical/Membrane Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Muscle Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Potassium Channels, Inwardly..., http://linkedlifedata.com/resource/pubmed/chemical/Slc1a3 protein, mouse, http://linkedlifedata.com/resource/pubmed/chemical/dystrobrevin, http://linkedlifedata.com/resource/pubmed/chemical/potassium inwardly-rectifying..., http://linkedlifedata.com/resource/pubmed/chemical/syntrophin alpha1
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0894-1491
pubmed:author
pubmed:copyrightInfo
2005 Wiley-Liss, Inc.
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
53
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
124-31
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
Potassium channel Kir4.1 macromolecular complex in retinal glial cells.
pubmed:affiliation
Department of Neuroscience, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
pubmed:publicationType
Journal Article, Research Support, N.I.H., Extramural