Sea anemone neurotoxin is the name given to

neurotoxin Neurotoxins are toxins that are destructive to nerve tissue (causing neurotoxicity). Neurotoxins are an extensive class of exogenous chemical neurological insultsSpencer 2000 that can adversely affect function in both developing and matur ...

s produced by sea anemones with related structure and function. Sea anemone neurotoxins can be divided in two functional groups that either specifically target the sodium channel or the potassium channel. A number of proteins belong to the sodium channel toxin family, including '' calitoxin'' and ''

anthopleurin Anthopleurin is a toxin from the venom of the sea anemones ''Anthopleura xanthogrammica'' and ''Anthopleura elegantissima''. These anemones use anthopleurin as a pheromone to quickly withdraw their tentacles in the presence of predators. Anthopleu ...

''. The neurotoxins bind specifically to the sodium channel, thereby delaying its inactivation during signal transduction, resulting in strong stimulation of mammalian cardiac muscle contraction. Calitoxin 1 has been found in neuromuscular preparations of

crustacean Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean gro ...

s, where it increases transmitter release, causing firing of the

axon An axon (from Greek ἄξων ''áxōn'', axis), or nerve fiber (or nerve fibre: see spelling differences), is a long, slender projection of a nerve cell, or neuron, in vertebrates, that typically conducts electrical impulses known as action ...

s. Three disulfide bonds are present in this protein. This family also includes the

antihypertensive Antihypertensives are a class of drugs that are used to treat hypertension (high blood pressure). Antihypertensive therapy seeks to prevent the complications of high blood pressure, such as stroke and myocardial infarction. Evidence suggests that ...

and antiviral proteins BDS-I () and BDS-II () expressed by ''

Anemonia viridis ''Anemonia'' is a genus of sea anemones belonging to the family Actiniidae. Species The following species are recognized: * '' Anemonia alicemartinae'' Häussermann & Försterra, 2001 * '' Anemonia antilliensis'' Pax, 1924 * '' Anemonia cereus ...

'' (previously ''

Anemonia sulcata ''Anemonia sulcata'', or Mediterranean snakelocks sea anemone, is a species of sea anemone in the family Actiniidae from the Mediterranean Sea. Whether ''A. sulcata'' should be recognized as a synonym of '' A. viridis'' remains a matter of disput ...

)''. BDS-I is organised into a triple-stranded antiparallel beta-sheet, with an additional small antiparallel beta-sheet at the N-terminus. Both peptides are known to specifically block the Kv3.4 potassium channel, and thus bring about a decrease in blood pressure. Moreover, they inhibit the cytopathic effects of mouse hepatitis virus strain MHV-A59 on mouse liver cells, by an unknown mechanism. The potassium channel toxin family include kaliseptine and kalicludines, and was also isolated from ''

''.

References

Protein domains * Peripheral membrane proteins Neurotoxins {{membrane-protein-stub

See also

References