Linked Life Data

10660562

Source:http://linkedlifedata.com/resource/pubmed/id/10660562

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2000-3-16
pubmed:databankReference
pubmed:abstractText
Glutamine is the preferred precursor for the neurotransmitter pool of glutamate, the major excitatory transmitter in the mammalian central nervous system. We have isolated a complementary DNA clone (designated GlnT) encoding a plasma membrane glutamine transporter from glutamatergic neurons in culture, and its properties have been examined using the T7 vaccinia system in fibroblasts. When GlnT is transfected into CV-1 cells, L-glutamine is the preferred substrate. Transport is Na(+)-dependent and inhibited by alpha-methylaminoisobutyric acid, a specific inhibitor of neutral amino acid transport system A. Kinetic analysis of glutamine uptake by GlnT is saturable, with a Michaelis constant (K(m)) of 489 +/- 88 microM at pH 7.4. Glutamine uptake mediated by GlnT is pH-sensitive with a 5-fold greater efficiency of uptake at pH 8.2 than at pH 6.6. Only the maximal velocity of transport increases without a significant change in K(m). The distribution of GlnT mRNA and protein in the central nervous system is widespread and is expressed on neurons that use glutamate as their neurotransmitter. In cultured cerebellar granule cells, GlnT is expressed only on neurons and is absent from astrocytes. GlnT expression increases concomitantly with the morphologic and functional differentiation of these cells in vitro, consistent with its role of supplying glutamatergic neurons with their neurotransmitter precursor. GlnT is the first member of the system A family of neutral amino acid transporters with 11 putative membrane-spanning domains and is a potential target to modulate presynaptic glutamatergic function.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
11
pubmed:volume
275
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
4049-54
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:10660562-Amino Acid Transport Systems, Basic, pubmed-meshheading:10660562-Aminoisobutyric Acids, pubmed-meshheading:10660562-Animals, pubmed-meshheading:10660562-COS Cells, pubmed-meshheading:10660562-Carrier Proteins, pubmed-meshheading:10660562-Cells, Cultured, pubmed-meshheading:10660562-Cerebellum, pubmed-meshheading:10660562-Cloning, Molecular, pubmed-meshheading:10660562-Fluorescent Antibody Technique, pubmed-meshheading:10660562-Hydrogen-Ion Concentration, pubmed-meshheading:10660562-In Situ Hybridization, pubmed-meshheading:10660562-Kinetics, pubmed-meshheading:10660562-Membrane Proteins, pubmed-meshheading:10660562-Molecular Sequence Data, pubmed-meshheading:10660562-Neurons, pubmed-meshheading:10660562-RNA, Messenger, pubmed-meshheading:10660562-Rats, pubmed-meshheading:10660562-Rats, Sprague-Dawley, pubmed-meshheading:10660562-Sequence Homology, Amino Acid, pubmed-meshheading:10660562-Transfection
pubmed:year
2000
pubmed:articleTitle
Cloning and functional identification of a neuronal glutamine transporter.
pubmed:affiliation
Neuroscience Center, Louisiana State University Health Sciences Center, New Orleans, Louisiana 70112, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.