title: Argiotoxin detects molecular differences in AMPA receptor channels.
abstract: 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.
authors.affiliation: Abteilung Zellphysiologie, Max-Planck-Institut für medizinische Forschung, Heidelberg, Federal Republic of Germany.
authors.forename: S
authors.initials: S
authors.lastname: Herlitze
authors.forename: M
authors.initials: M
authors.lastname: Raditsch
authors.forename: J P
authors.initials: JP
authors.lastname: Ruppersberg
authors.forename: W
authors.initials: W
authors.lastname: Jahn
authors.forename: H
authors.initials: H
authors.lastname: Monyer
authors.forename: R
authors.initials: R
authors.lastname: Schoepfer
authors.forename: V
authors.initials: V
authors.lastname: Witzemann
mesh_terms: 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
chemical_list: 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