Linked Life Data

9502796

Source:http://linkedlifedata.com/resource/pubmed/id/9502796

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7
pubmed:dateCreated
1998-4-7
pubmed:abstractText
P2X receptors are a family of ATP-gated ion channels thought to have intracellular N and C termini and two transmembrane segments separating a large extracellular domain. We examined the involvement of the second putative transmembrane domain (TM2) of the P2X2 subunit in ion conduction, using the substituted cysteine accessibility method (SCAM). This method tests the ability of hydrophilic reagents such as Ag+ or the methanethiosulfonates to modify covalently the sulfhydryl side chains exposed to aqueous environments. ATP-gated current was measured in HEK293 cells transiently expressing either wild-type or functional mutant P2X2 receptors containing a cysteine substitution in or around TM2. Application of Ag+ to gating channels had no sustained effect on wild-type P2X2 (WT) but irreversibly altered whole-cell currents in 15 mutants. By contrast, bath application of (2-aminoethyl)methanethiosulfonate (MTSEA) to closed channels inhibited 8 of the 15 residues affected by Ag+ when the channel was gating. Inhibition of the closed channel was prevented in seven of eight mutants when membrane-permeant MTSEA was scavenged by 20 mM intracellular cysteine, indicating that these seven mutants lie on the intracellular side of the channel gate. Further, MTSEA inhibited current through G342C in the absence of intracellular cysteine but augmented the current when cysteine was present, suggesting that this residue may be part of the gate. Taken together, the data help to the identify a functional domain of the channel pore by mapping residues on either side of the channel gate.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0270-6474
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
18
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2350-9
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed-meshheading:9502796-Adenosine Triphosphate, pubmed-meshheading:9502796-Amino Acid Sequence, pubmed-meshheading:9502796-Cells, Cultured, pubmed-meshheading:9502796-Cysteine, pubmed-meshheading:9502796-Dose-Response Relationship, Drug, pubmed-meshheading:9502796-Ethyl Methanesulfonate, pubmed-meshheading:9502796-Humans, pubmed-meshheading:9502796-Indicators and Reagents, pubmed-meshheading:9502796-Ion Channel Gating, pubmed-meshheading:9502796-Kidney, pubmed-meshheading:9502796-Membrane Potentials, pubmed-meshheading:9502796-Molecular Sequence Data, pubmed-meshheading:9502796-Mutagenesis, Site-Directed, pubmed-meshheading:9502796-Neuropeptides, pubmed-meshheading:9502796-Protein Structure, Secondary, pubmed-meshheading:9502796-Protein Structure, Tertiary, pubmed-meshheading:9502796-Receptors, Purinergic P2, pubmed-meshheading:9502796-Receptors, Purinergic P2X2, pubmed-meshheading:9502796-Silver, pubmed-meshheading:9502796-Water
pubmed:year
1998
pubmed:articleTitle
A domain contributing to the ion channel of ATP-gated P2X2 receptors identified by the substituted cysteine accessibility method.
pubmed:affiliation
Department of Pharmacological and Physiological Sciences, St. Louis University Health Sciences Center, St. Louis, Missouri 63104, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.