Linked Life Data

8663494

Source:http://linkedlifedata.com/resource/pubmed/id/8663494

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
30
pubmed:dateCreated
1996-9-3
pubmed:abstractText
Nicotinic acetylcholine receptors formed from combinations of alpha3, beta2, beta4, and alpha5 subunits are found in chicken ciliary ganglion neurons and some human neuroblastoma cell lines. We studied the co-expression of various combinations of cloned human alpha3, beta2, beta4, and alpha5 subunits in Xenopus oocytes. Expression on the surface membrane was found only for combinations of alpha3beta2, alpha3beta4, alpha3beta2alpha5, and alpha3beta4alpha5 subunits but not for other combinations of one, two, or three of these subunits. alpha5 subunits assembled inside the oocyte with beta2 but not with alpha3 subunits or other alpha5 subunits. alpha5 subunits coassembled very efficiently with alpha3beta2 or alpha3beta4 combinations. The presence of alpha5 subunits had very little effect on the binding affinities for epibatidine of receptors containing also alpha3 and beta2 or alpha3 and beta4 subunits. The presence of alpha5 subunits increased the rate of desensitization of both receptors containing also alpha3 and beta2 or alpha3 and beta4 subunits. In the case of receptors containing alpha3 and beta4 subunits, the addition of alpha5 subunits had little effect on the responses to acetylcholine or nicotine. However, in the case of receptors containing alpha3 and beta2 subunits, the addition of alpha5 subunits reduced the EC50 for acetylcholine from 28 to 0.5 microM and the EC50 for nicotine from 6.8 to 1.9 microM, while increasing the efficacy of nicotine from 50% on alpha3beta2 receptors to 100% on alpha3beta2alpha5 receptors. Both alpha3beta2 and alpha3beta2alpha5 receptors expressed in oocytes sedimented at the same 11 S value as native alpha3-containing receptors from the human neuroblastoma cell line SH-SY5Y. In the receptors from the neuroblastoma alpha3, beta2, and alpha5 subunits were co-assembled, and 56% of the receptor subtypes containing alpha3 subunits also contained beta2 subunits. The beta2 subunit-containing receptors from SH-SY5Y cells exhibited the high affinity for epibatidine characteristic of receptors formed from alpha3 and beta2 or alpha3, beta2, and alpha5 subunits rather than the low affinity exhibited by receptors formed from alpha3 and beta4 or alpha3, beta4, and alpha5 subunits. Nicotine, like the structurally similar toxin epibatidine, also distinguishes by binding affinity two subtypes of receptors containing alpha3 subunits in SH-SY5Y cells. The affinities of alpha3beta2 receptors expressed in oocytes were similar to the affinities of native alpha3 containing receptors from SH-SY5Y cells for acetylcholine, cytisine, and 1,1-dimethyl-4-phenylpiperazinium.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
26
pubmed:volume
271
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
17656-65
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:8663494-Acetylcholine, pubmed-meshheading:8663494-Amino Acid Sequence, pubmed-meshheading:8663494-Animals, pubmed-meshheading:8663494-Bicyclo Compounds, Heterocyclic, pubmed-meshheading:8663494-Cloning, Molecular, pubmed-meshheading:8663494-Electrophysiology, pubmed-meshheading:8663494-Humans, pubmed-meshheading:8663494-Models, Molecular, pubmed-meshheading:8663494-Molecular Sequence Data, pubmed-meshheading:8663494-Neuroblastoma, pubmed-meshheading:8663494-Neurons, pubmed-meshheading:8663494-Nicotinic Agonists, pubmed-meshheading:8663494-Protein Conformation, pubmed-meshheading:8663494-Pyridines, pubmed-meshheading:8663494-Receptors, Nicotinic, pubmed-meshheading:8663494-Recombinant Proteins, pubmed-meshheading:8663494-Tumor Cells, Cultured, pubmed-meshheading:8663494-Xenopus
pubmed:year
1996
pubmed:articleTitle
Assembly of human neuronal nicotinic receptor alpha5 subunits with alpha3, beta2, and beta4 subunits.
pubmed:affiliation
Department of Neuroscience, University of Pennsylvania Medical School, Philadelphia, Pennsylvania 19104-6074, USA.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't