Arginine-481 mutation abolishes ligand-binding of the AMPA-selective glutamate receptor channel alpha1-subunit.
Arginine-481 is located in the putative agonist-binding region preceding the putative transmembrane segment M1 of the alpha1-subunit of the AMPA-selective glutamate receptor (GluR) channel. This amino acid is completely conserved among GluR proteins. A site-directed mutagenesis study using a baculovirus expression system showed that substitution of glutamate, glutamine and lysine for arginine-481 of the recombinant alpha1-subunit protein abolishes binding to [3H]AMPA completely. The present study provides the first direct experimental evidence that the conserved charged arginine-481 residue is essential, directly or indirectly, for the acquisition of ligand-binding activity by the receptor protein.
Kawamoto
S
S
Department of Bacteriology, Yokohama City University School of Medicine, Kanazawa-ku, Yokohama, Japan. skawamot@med.yokohama-cu.ac.jp
Uchino
S
S
Xin
K Q
KQ
Hattori
S
S
Hamajima
K
K
Fukushima
J
J
Mishina
M
M
Okuda
K
K
D000818:Animals; D001120:Arginine / Q000378:metabolism*; D001483:Base Sequence; D007473:Ion Channels / Q000187:drug effects; D051379:Mice; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics*; D011869:Radioligand Assay; D017470:Receptors, Glutamate / Q000187:drug effects* / Q000378:metabolism; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid / Q000494:pharmacology*
D007473:Ion Channels; D017470:Receptors, Glutamate; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid; D001120:Arginine