Novel peptide toxins recently isolated from sea anemones.
Sea anemones are a rich source of peptide toxins acting on ion channels. Two classes of peptide toxins, site-3 sodium channel toxins and Kv1 potassium channel toxins, have been well characterized and some of them used as valuable pharmacological reagents. Recently, the following six peptides toxins, which structurally constitute a new family but target different ion channels, have been isolated: BDS-I and -II (Kv3 potassium channel toxins) from Anemonia sulcata, APETx1 (human ether-a-go-go-related gene potassium channel toxin) and APETx2 (acid-sensing sodium channel toxin) from Anthopleura elegantissima, BcIV (sodium channel toxin) from Bunodosoma caissarum and Am II (whose target is unknown) from Antheopsis maculata. In addition, the following structurally novel peptide toxins have also emerged in sea anemones: gigantoxin I (epidermal growth factor-like toxin) from Stichodactyla gigantea and acrorhagins I and II from acrorhagi (specialized aggressive organs) of Actinia equina. This review deals with the structural and functional features of these recently isolated sea anemone peptide toxins that are promising tools in studying the physiology of diverse ion channels.
Shiomi
Kazuo
K
Department of Food Science and Technology, Tokyo University of Marine Science and Technology, Konan-4, Minato-ku, Tokyo 108-8477, Japan. shiomi@kaiyodai.ac.jp
D000595:Amino Acid Sequence; D000818:Animals; D007473:Ion Channels / Q000378:metabolism; D008387:Marine Toxins / Q000737:chemistry / Q000302:isolation & purification / Q000633:toxicity; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry / Q000302:isolation & purification / Q000633:toxicity; D012615:Sea Anemones / Q000737:chemistry* / Q000145:classification / Q000502:physiology; D013329:Structure-Activity Relationship
D007473:Ion Channels; D008387:Marine Toxins; D010455:Peptides