Faculty Collaboration Database

Biochemical and morphological characterization of an intracellular membrane compartment containing AMPA receptors. Neuropharmacology 2001 Nov;41(6):680-92

Date

10/20/2001

Pubmed ID

11640922

DOI

10.1016/s0028-3908(01)00124-1

Scopus ID

2-s2.0-0034800294 (requires institutional sign-in at Scopus site)   57 Citations

Abstract

AMPA receptors cycle rapidly in and out of the postsynaptic membrane, while NMDA receptors are relatively immobile. Changing the distribution of AMPA receptors between intracellular and surface synaptic pools is an important means of controlling synaptic strength. However, little is known about the intracellular membrane compartments of neurons that contain AMPA receptors. Here we describe biochemical and morphological characteristics of an intracellular pool of AMPA receptors in rat brain. By velocity gradient centrifugation of microsomal light membranes from rat brain, we identified a membrane fraction enriched for AMPA receptor subunits GluR2/3 but lacking NMDA receptors. This membrane compartment sedimented more slowly than synaptosomes but faster than synaptic vesicles and cofractionated with GRIP, PICK-1 and syntaxin-13. Morphological examination of this fraction revealed round and tubular vesicles ranging from approximately 50 to 300 nm in diameter. Immunocytochemistry of cultured hippocampal neurons showed that a significant portion of AMPA receptors colocalized with syntaxin-13 (a SNARE protein associated with tubulovesicular recycling endosomes) and with transferrin receptors. Taken together, these results suggest that a pool of intracellular GluR2/3 resides in a syntaxin 13-positive tubulovesicular membrane compartment, which might serve as a reservoir for the dendritic recycling of AMPA receptors.

Author List

Lee SH, Valtschanoff JG, Kharazia VN, Weinberg R, Sheng M

Author

Sang H. Lee PhD Professor in the Pharmacology and Toxicology department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Animals
Cells, Cultured
Centrifugation, Density Gradient
Cerebral Cortex
Endosomes
Glycerol
Hippocampus
Intracellular Membranes
Male
Membrane Proteins
Microscopy, Immunoelectron
Neurons
Prosencephalon
Qa-SNARE Proteins
Rats
Rats, Sprague-Dawley
Receptors, AMPA
Receptors, Glutamate
Receptors, N-Methyl-D-Aspartate
Subcellular Fractions
Synaptic Vesicles