Argiotoxin detects molecular differences in AMPA receptor channels.
Argiotoxin, a component of the spider venom from Argiope lobata, blocks AMPA receptor channels expressed in homomeric and heteromeric configuration in Xenopus oocytes. Argiotoxin acts as an open channel blocker in a voltage-dependent manner and discriminates between the functionally diverse AMPA receptors. Importantly, a transmembrane region 2 determinant for divalent cation permeability also determines argiotoxin sensitivity. Subunit-specific differences in the time courses of block and recovery demonstrate that heteromeric AMPA receptors can assemble in variable ratios. Thus, argiotoxin can be used as a tool in analyzing the subunit composition of AMPA receptors in native membranes.
Herlitze
S
S
Abteilung Zellphysiologie, Max-Planck-Institut für medizinische Forschung, Heidelberg, Federal Republic of Germany.
Raditsch
M
M
Ruppersberg
J P
JP
Jahn
W
W
Monyer
H
H
Schoepfer
R
R
Witzemann
V
V
D000818:Animals; D001483:Base Sequence; D002462:Cell Membrane / Q000187:drug effects / Q000502:physiology; D005071:Evoked Potentials / Q000187:drug effects; D005260:Female; D007210:Indoleacetic Acids; D007473:Ion Channels / Q000187:drug effects / Q000502:physiology*; D007608:Kainic Acid / Q000494:pharmacology; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D016296:Mutagenesis; D009838:Oligodeoxyribonucleotides; D009865:Oocytes / Q000187:drug effects / Q000502:physiology*; D010648:Phenylacetates / Q000494:pharmacology*; D011073:Polyamines / Q000494:pharmacology*; D011487:Protein Conformation; D018091:Receptors, AMPA; D017470:Receptors, Glutamate / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D013111:Spider Venoms / Q000494:pharmacology*; D014982:Xenopus laevis
D007210:Indoleacetic Acids; D007473:Ion Channels; D046911:Macromolecular Substances; D009838:Oligodeoxyribonucleotides; D010648:Phenylacetates; D011073:Polyamines; D018091:Receptors, AMPA; D017470:Receptors, Glutamate; D013111:Spider Venoms; C558368:argiotoxin-636; D007608:Kainic Acid