Linked Life Data

12670305

Source:http://linkedlifedata.com/resource/pubmed/id/12670305

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2003-4-2
pubmed:abstractText
AMPA-type glutamate receptors (AMPAR) display a high variability in functional properties, which determine the time course of excitatory postsynaptic potentials. They are assembled as tetramers of GluR subunits 1-4 of different splice variants and nuclear edited isoforms. Presently, the kinetics of activation, desensitization and recovery from desensitization of human AMPARs (GluR1, 3 and 4 flip and flop, and GluR2 flip and flop in R and G edited forms, respectively) transiently expressed in HEK293 cells were studied with patch-clamp techniques and ultra fast agonist application. Activation time constants were identical for all receptors (0.13 ms). The GluR2 flip G variant showed the slowest desensitization (10.8 ms), GluR4 flip the fastest (1.6 ms). Recovery from desensitization varied between 3.1 ms (GluR4 flip) and 178 ms (GluR1 flip). To determine functional interactions between subunits in heteromeric receptors the GluR1 flip and the GluR2 flip R were coexpressed. The time constant of desensitization increased linearly from 2.5 ms (GluR1 flip homomers) to 6.8 ms (GluR2 flip R homomers) with the amount of GluR2 flip R cDNA transfected. Recovery followed a monoexponential time course and had a time constant of 178 ms in GluR1 flip homomeric expression. In all GluR1 flip/GluR2 flip heteromers and in GluR2 flip R homomers desensitization recovered with a time constant of approximately 50 ms. Thus, subunit interaction seems likely during recovery but not desensitization. Both parameters might influence the ability of AMPA receptors to mediate glutamate induced chronic excitotoxicity in neurodegenerative diseases.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0953-816X
pubmed:author
pubmed:issnType
Print
pubmed:volume
17
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1173-8
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
Kinetic properties of human AMPA-type glutamate receptors expressed in HEK293 cells.
pubmed:affiliation
Department of Neurology, Medizinische Hochschule Hannover, 30625 Hannover. grosskreutz.julian@mh-hannover.de
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't