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Titolo:
HIGH-AFFINITY AND LOW-AFFINITY [H-3]AMINO-3-HYDROXY-5-METHYLISOXAZOLE-4-PROPIONIC ACID ([H-3]AMPA) BINDING-SITES REPRESENT IMMATURE AND MATURE FORMS OF AMPA RECEPTORS AND ARE COMPOSED OF DIFFERENTIALLY GLYCOSYLATED SUBUNITS
Autore:
STANDLEY S; TOCCO G; WAGLE N; BAUDRY M;
Indirizzi:
UNIV SO CALIF,NEUROSCI PROGRAM,HEDCO NEUROSCI BLDG LOS ANGELES CA 90089
Titolo Testata:
Journal of neurochemistry
fascicolo: 6, volume: 70, anno: 1998,
pagine: 2434 - 2445
SICI:
0022-3042(1998)70:6<2434:HAL[>2.0.ZU;2-R
Fonte:
ISI
Lingua:
ENG
Soggetto:
LONG-TERM POTENTIATION; RAT-BRAIN; MESSENGER-RNA; SUBCELLULAR-LOCALIZATION; QUISQUALATE RECEPTORS; LTP INDUCTION; HIPPOCAMPUS; EXPRESSION; NMDA; MEMBRANES;
Keywords:
RECEPTORS; LPHA-AMINO-3-HYDROXY-5-METHYLISOXAZOLE-4-PROPIONIC ACID; GLUTAMATE; GLYCOSYLATION; SUBCELLULAR; PLASTICITY;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Science Citation Index Expanded
Citazioni:
54
Recensione:
Indirizzi per estratti:
Citazione:
S. Standley et al., "HIGH-AFFINITY AND LOW-AFFINITY [H-3]AMINO-3-HYDROXY-5-METHYLISOXAZOLE-4-PROPIONIC ACID ([H-3]AMPA) BINDING-SITES REPRESENT IMMATURE AND MATURE FORMS OF AMPA RECEPTORS AND ARE COMPOSED OF DIFFERENTIALLY GLYCOSYLATED SUBUNITS", Journal of neurochemistry, 70(6), 1998, pp. 2434-2445

Abstract

Quantitative [H-3]amino-3-hydroxy-5-methylisoxazole-4-propionic acid ([H-3]AMPA) binding autoradiography was performed on frozen-thawed sections from rat brain after preincubation at 0 or 35 degrees C for 1 h. Preincubation at 35 degrees C instead of 0 degrees C resulted in a selective decrease of [H-3]AMPA binding assayed at a low concentration of [H-3]-AMPA (50 nM) and an enhancement of binding at a high concentration (500 nM). The decrease in [H-3]AMPA binding after preincubation at 35 degrees C was accompanied with the loss of the lighter organellesof P3 (microsomal) fractions. These organelles were found to contain a small subpopulation of AMPA/GluR receptors exhibiting a high affinity for [H-3]AMPA (K-D similar to 14 nM), whereas heavier organelles exhibited lower affinity for AMPA (K-D similar to 190 nM). This small subpopulation of AMPA/GluR receptors contained almost exclusively a structurally distinct species of GluR2/3 subunits with an apparent molecular mass of 103.5 kDa (assessed with anti-GluR2/3, C-terminal antibodies). Experiments using two deglycosylating enzymes, N-glycopeptidase F and endoglycosidase H, clearly indicated that the 103.5-kDa species represented a partially unglycosylated form of GluR2/3 subunits containing the high-mannose type of oligosaccharide moiety, whereas receptors present in synaptosomal fractions were composed of subunits with complex oligosaccharides. A similar result was obtained by using an antibodyrecognizing the N-terminal domain of GluR2(4). The same enzymatic treatment indicated that GluR1 subunits also exhibited a partially glycosylated form. These data indicate that high-affinity [H-3]AMPA binding sites represent nonsynaptic, intracellular membrane-bound AMPA receptors that differ from synaptic receptors by at least the glycosylation state of GluR2 (and GluR1) subunits. In addition, our results provide arelatively simple way of assessing changes in two spatially and structurally distinct [H-3]AMPA binding/GluR sites.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 20/01/21 alle ore 02:21:20