Tarantula toxins interacting with voltage sensors in potassium channels.
Voltage-activated ion channels open and close in response to changes in membrane voltage, a process that is crucial for electrical signaling in the nervous system. The venom from many poisonous creatures contains a diverse array of small protein toxins that bind to voltage-activated channels and modify the gating mechanism. Hanatoxin and a growing number of related tarantula toxins have been shown to inhibit activation of voltage-activated potassium (K(v)) channels by interacting with their voltage-sensing domains. This review summarizes our current understanding of the mechanism by which these toxins alter gating, the location of the toxin receptor within K(v) channels and the disposition of this receptor with respect to the lipid membrane. The conservation of tarantula toxin receptors among voltage-activated ion channels will also be discussed.
Swartz
Kenton J
KJ
Molecular Physiology and Biophysics Section, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA. swartzk@ninds.nih.gov
D000595:Amino Acid Sequence; D000818:Animals; D006801:Humans; D015640:Ion Channel Gating / Q000187:drug effects / Q000502:physiology; D008969:Molecular Sequence Data; D015221:Potassium Channels / Q000187:drug effects*; D016415:Sequence Alignment; D013111:Spider Venoms / Q000235:genetics* / Q000494:pharmacology*
D015221:Potassium Channels; D013111:Spider Venoms