Linked Life Data

2152799

Source:http://linkedlifedata.com/resource/pubmed/id/2152799

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1990-1-19
pubmed:abstractText
The coupling mechanism of the gamma-aminobutyric acid (GABA)B receptor, one of the subtypes of GABA receptors, with calcium ion channel and GTP-binding protein was examined using a crude synaptic membrane (P2) fraction from the bovine cerebral cortex and a fraction solubilized with sodium deoxycholate. In the P2 fraction, [3H]GABA binding to the GABAB receptor was increased significantly by the addition of calcium ion, and this enhancement was accentuated further by calcium ion channel blockers such as nicardipine and diltiazem. In contrast, N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide (W-7), a calmodulin antagonist, did not affect on the calcium ion-induced enhancement of GABAB receptor binding. These results suggest that the GABAB receptor may be functionally coupled with the calcium ion channel, which exhibits an inhibitory modulation against the receptor. On the other hand, GABAB receptor binding, which was noncompetitively inhibited by guanine nucleotides such as GTP, guanosine 5'-(3-O-thio)triphosphate (GTP gamma S), guanosine 5'-(beta, gamma-imido)triphosphate [Gpp(NH)p], and GDP, was competitively inhibited by (-)-baclofen. Although the affinity of (-)-baclofen for the GABAB receptor was decreased in the presence of GTP, pretreatment of the P2 fraction with islet-activating protein (IAP) eliminated the effect of GTP. In addition, GABA and (-)-baclofen induced an increase of GTPase activity in the P2 fraction, and this increase was also eliminated by treatment with IAP. These results suggest that the GABAB receptor may also be functionally coupled with IAP-sensitive GTP-binding protein. Treatment of the P2 fraction with sodium deoxycholate resulted in the highest solubilization of GABAB receptor among various detergents examined.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0022-3042
pubmed:author
pubmed:issnType
Print
pubmed:volume
54
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
80-5
pubmed:dateRevised
2003-11-14
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
Functional coupling of the gamma-aminobutyric acidB receptor with calcium ion channel and GTP-binding protein and its alteration following solubilization of the gamma-aminobutyric acidB receptor.
pubmed:affiliation
Department of Pharmacology, Kyoto Prefectural University of Medicine, Japan.
pubmed:publicationType
Journal Article