MEMBRANE TOPOLOGY OF THE HIGH-AFFINITY L-GLUTAMATE TRANSPORTER (GLAST-1) OF THE CENTRAL-NERVOUS-SYSTEM

Authors
Citation
S. Wahle et W. Stoffel, MEMBRANE TOPOLOGY OF THE HIGH-AFFINITY L-GLUTAMATE TRANSPORTER (GLAST-1) OF THE CENTRAL-NERVOUS-SYSTEM, The Journal of cell biology, 135(6), 1996, pp. 1867-1877
Citations number
60
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Cell Biology
Journal title
ISSN journal
0021-9525
Volume
135
Issue
6
Year of publication
1996
Part
2
Pages
1867 - 1877
Database
ISI
SICI code
0021-9525(1996)135:6<1867:MTOTHL>2.0.ZU;2-R
Abstract
The membrane topology of the high affinity, Na+-coupled L-glutamate/L- aspartate transporter (GLAST-1) of the central nervous system has been determined. Truncated GLAST-1 cDNA constructs encoding protein fragme nts with an increasing number of hydrophobic regions were fused to a c DNA encoding a reporter peptide with two N-glycosylation sites, The re spective cRNA chimeras were translated in vitro and in vivo in Xenopus oocytes. Posttranslational N-glycosylation of the two reporter consen sus sites monitors the number, size, and orientation of membrane-spann ing domains, The results of our experiments suggest a novel 10-transme mbrane domain topology of GLAST-1, a representative of the L-glutamate neurotransmitter transporter family, with its NH2 and COOH termini on the cytoplasmic side, six NH2-terminal hydrophobic transmembrane alph a-helices, and four COOH-terminal short hydrophobic domains spanning t he bilayer predicted as beta-sheets.