Phylogenetic conservation of disulfide-linked, dimeric acetylcholine receptor pentamers in southern ocean electric rays
Intact acetylcholine receptors have been purified on a novel affinity resin from three electric fish endemic to Australian waters. Their binding properties and morphology are compared with those of their northern hemisphere homolog, Torpedo marmorata. All four exhibit apparent dissociation constants...
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ftanucanberra:oai:digitalcollections.anu.edu.au:1885/86293 2023-05-15T18:25:04+02:00 Phylogenetic conservation of disulfide-linked, dimeric acetylcholine receptor pentamers in southern ocean electric rays Tierney, Mary (Louise) Osborn, Kate Milburn, Peter J Stowell, M Howitt, Susan 2015-12-13T23:07:38Z http://hdl.handle.net/1885/86293 unknown The Company of Biologists Ltd 0022-0949 http://hdl.handle.net/1885/86293 Journal of Experimental Biology Journal article 2015 ftanucanberra 2015-12-28T23:39:03Z Intact acetylcholine receptors have been purified on a novel affinity resin from three electric fish endemic to Australian waters. Their binding properties and morphology are compared with those of their northern hemisphere homolog, Torpedo marmorata. All four exhibit apparent dissociation constants, K d, in the nanomolar range for the snake neurotoxin α-bungarotoxin and have a distinctive rosette-like appearance when viewed in negative stain under the electron microscope. Furthermore, these rosettes are paired, indicating that acetylcholine receptors from southern ocean electric fish exist as dimers, in the same fashion as their northern hemisphere counterparts. The cDNAs of the receptor's four subunits were sequenced from Hypnos monopterigium and the northern hemisphere counterpart, Torpedo marmorata, while cDNAs from only two subunits, α and δ, were able to be sequenced from Narcine tasmaniensis. The penultimate amino acid in the δ subunit of each of the newly sequenced fish species is a cysteine residue. Its conservation suggests that the mechanism for the observed dimerization of acetylcholine receptors is disulfide bond formation between the δ subunit of adjacent receptors, analogous to acetylcholine receptor dimers observed in other electric fish. It appears that this mechanism for receptor clustering is unique to acetylcholine receptors packed and organized in the specialized organs of electric fish. Alignment of the deduced protein sequences with the equivalent sequences from Torpedo californica and humans reveals a high degree of homology. Article in Journal/Newspaper Southern Ocean Australian National University: ANU Digital Collections Southern Ocean |
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Australian National University: ANU Digital Collections |
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ftanucanberra |
language |
unknown |
description |
Intact acetylcholine receptors have been purified on a novel affinity resin from three electric fish endemic to Australian waters. Their binding properties and morphology are compared with those of their northern hemisphere homolog, Torpedo marmorata. All four exhibit apparent dissociation constants, K d, in the nanomolar range for the snake neurotoxin α-bungarotoxin and have a distinctive rosette-like appearance when viewed in negative stain under the electron microscope. Furthermore, these rosettes are paired, indicating that acetylcholine receptors from southern ocean electric fish exist as dimers, in the same fashion as their northern hemisphere counterparts. The cDNAs of the receptor's four subunits were sequenced from Hypnos monopterigium and the northern hemisphere counterpart, Torpedo marmorata, while cDNAs from only two subunits, α and δ, were able to be sequenced from Narcine tasmaniensis. The penultimate amino acid in the δ subunit of each of the newly sequenced fish species is a cysteine residue. Its conservation suggests that the mechanism for the observed dimerization of acetylcholine receptors is disulfide bond formation between the δ subunit of adjacent receptors, analogous to acetylcholine receptor dimers observed in other electric fish. It appears that this mechanism for receptor clustering is unique to acetylcholine receptors packed and organized in the specialized organs of electric fish. Alignment of the deduced protein sequences with the equivalent sequences from Torpedo californica and humans reveals a high degree of homology. |
format |
Article in Journal/Newspaper |
author |
Tierney, Mary (Louise) Osborn, Kate Milburn, Peter J Stowell, M Howitt, Susan |
spellingShingle |
Tierney, Mary (Louise) Osborn, Kate Milburn, Peter J Stowell, M Howitt, Susan Phylogenetic conservation of disulfide-linked, dimeric acetylcholine receptor pentamers in southern ocean electric rays |
author_facet |
Tierney, Mary (Louise) Osborn, Kate Milburn, Peter J Stowell, M Howitt, Susan |
author_sort |
Tierney, Mary (Louise) |
title |
Phylogenetic conservation of disulfide-linked, dimeric acetylcholine receptor pentamers in southern ocean electric rays |
title_short |
Phylogenetic conservation of disulfide-linked, dimeric acetylcholine receptor pentamers in southern ocean electric rays |
title_full |
Phylogenetic conservation of disulfide-linked, dimeric acetylcholine receptor pentamers in southern ocean electric rays |
title_fullStr |
Phylogenetic conservation of disulfide-linked, dimeric acetylcholine receptor pentamers in southern ocean electric rays |
title_full_unstemmed |
Phylogenetic conservation of disulfide-linked, dimeric acetylcholine receptor pentamers in southern ocean electric rays |
title_sort |
phylogenetic conservation of disulfide-linked, dimeric acetylcholine receptor pentamers in southern ocean electric rays |
publisher |
The Company of Biologists Ltd |
publishDate |
2015 |
url |
http://hdl.handle.net/1885/86293 |
geographic |
Southern Ocean |
geographic_facet |
Southern Ocean |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_source |
Journal of Experimental Biology |
op_relation |
0022-0949 http://hdl.handle.net/1885/86293 |
_version_ |
1766206246411567104 |