title: Toxin modulators and blockers of hERG K(+) channels.
abstract: The K(+) channel encoded by the Ether-á-go-go-Related Gene (ERG) is expressed in different tissues of different animal species. There are at least three subtypes of this channel, being the sub-type 1 (ERG1) crucial in the repolarization phase of the cardiac action potential. Mutations in this gene can affect the properties of the channel producing the type II long QT syndrome (LQTS2) and many drugs are also known to affect this channel with a similar side effect. Various scorpion, spider and sea anemone toxins affect the ERG currents by blocking the ion-conducting pore from the external side or by modulating channel gating through binding to the voltage-sensor domain. By doing so, these toxins become very useful tools for better understanding the structural and functional characteristics of these ion channels. This review discusses the interaction between the ERG channels and the peptides isolated from venoms of these animals. Special emphasis is placed on scorpion toxins, although the effects of several spider venom toxins and anemone toxins will be also revised.
authors.affiliation: Department of Molecular Medicine and Bioprocesses, Institute of Biotechnology, National Autonomous University of Mexico, Av. Universidad 2001, P.O. Box 501-3, Cuernavaca 62210, Mexico. jimenez@ibt.unam.mx
authors.forename: J M
authors.initials: JM
authors.lastname: Jiménez-Vargas
authors.forename: R
authors.initials: R
authors.lastname: Restano-Cassulini
authors.forename: L D
authors.initials: LD
authors.lastname: Possani
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D003064:Cnidarian Venoms / Q000494:pharmacology; D051638:Ether-A-Go-Go Potassium Channels / Q000737:chemistry / Q000187:drug effects*; D006801:Humans; D015640:Ion Channel Gating; D008969:Molecular Sequence Data; D026902:Potassium Channel Blockers / Q000494:pharmacology*; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D012604:Scorpion Venoms / Q000494:pharmacology; D013045:Species Specificity; D013111:Spider Venoms / Q000494:pharmacology; D013329:Structure-Activity Relationship; D014688:Venoms / Q000494:pharmacology*
chemical_list: D003064:Cnidarian Venoms; D051638:Ether-A-Go-Go Potassium Channels; D026902:Potassium Channel Blockers; D012604:Scorpion Venoms; D013111:Spider Venoms; D014688:Venoms