Functional properties of the four Atlantic salmon (Salmo salar) aryl hydrocarbon receptor type 2 (AHR2) isoforms.
The aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor through which organochlorine contaminants including 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), and some polycyclic aromatic hydrocarbons induce toxicity and altered gene expression. Atlantic salmon has multiple AHR genes...
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ftulundlup:oai:lup.lub.lu.se:4225b801-6518-4178-9b40-b176104ecce2 2023-05-15T15:30:31+02:00 Functional properties of the four Atlantic salmon (Salmo salar) aryl hydrocarbon receptor type 2 (AHR2) isoforms. Hansson, Maria Hahn, Mark E 2008 https://lup.lub.lu.se/record/1035559 https://doi.org/10.1016/j.aquatox.2007.10.012 eng eng Elsevier https://lup.lub.lu.se/record/1035559 http://dx.doi.org/10.1016/j.aquatox.2007.10.012 pmid:18063141 wos:000253696200001 scopus:38549166269 Aquatic Toxicology; 86(2), pp 121-130 (2008) ISSN: 1879-1514 Ecology Gene expression Salmo salar Transcription TCDD Aryl hydrocarbon receptor Atlantic salmon contributiontojournal/article info:eu-repo/semantics/article text 2008 ftulundlup https://doi.org/10.1016/j.aquatox.2007.10.012 2023-02-01T23:28:38Z The aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor through which organochlorine contaminants including 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), and some polycyclic aromatic hydrocarbons induce toxicity and altered gene expression. Atlantic salmon has multiple AHR genes, of which two belong to the AHR1 clade and four belong to the AHR2 clade. The four AHR2 forms (alpha, beta, gamma, delta) are more highly expressed than the AHR1 (alpha, beta,) forms and all six AHRs are highly similar in pairs, likely originating from a whole-genome duplication in the salmonid ancestor. It has been speculated that having multiple AHRs contributes to the very high sensitivity of salmonid species to TCDD and related chemicals. To test the hypothesis that all four salmon AHR2 proteins are expressed and functional, we measured mRNA transcription for each AHR2 in several tissues, cloned the cDNAs and evaluated the functional properties of the expressed proteins. Analysis by real-time PCR revealed that the receptors showed differences in transcript levels among salmon tissues and that in general AHR2alpha was transcribed at higher levels than the other three AHR2s. Velocity sedimentation analysis showed that all four in vitro-expressed AHR2 proteins exhibit specific, high-affinity binding of [(3)H]TCDD. When expressed in COS-7 cells, all four AHR2 proteins were able to drive the expression of a reporter gene under control of murine CYP1A1 enhancer elements. From EC(50) values determined in TCDD concentration-response experiments, all four salmon AHR2s show similar sensitivity to TCDD. In summary, all four Atlantic salmon AHR2 appear to function in AHR-mediated signaling, suggesting that all four proteins are involved in TCDD-mediated toxicity. Article in Journal/Newspaper Atlantic salmon Salmo salar Lund University Publications (LUP) Aquatic Toxicology 86 2 121 130 |
institution |
Open Polar |
collection |
Lund University Publications (LUP) |
op_collection_id |
ftulundlup |
language |
English |
topic |
Ecology Gene expression Salmo salar Transcription TCDD Aryl hydrocarbon receptor Atlantic salmon |
spellingShingle |
Ecology Gene expression Salmo salar Transcription TCDD Aryl hydrocarbon receptor Atlantic salmon Hansson, Maria Hahn, Mark E Functional properties of the four Atlantic salmon (Salmo salar) aryl hydrocarbon receptor type 2 (AHR2) isoforms. |
topic_facet |
Ecology Gene expression Salmo salar Transcription TCDD Aryl hydrocarbon receptor Atlantic salmon |
description |
The aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor through which organochlorine contaminants including 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), and some polycyclic aromatic hydrocarbons induce toxicity and altered gene expression. Atlantic salmon has multiple AHR genes, of which two belong to the AHR1 clade and four belong to the AHR2 clade. The four AHR2 forms (alpha, beta, gamma, delta) are more highly expressed than the AHR1 (alpha, beta,) forms and all six AHRs are highly similar in pairs, likely originating from a whole-genome duplication in the salmonid ancestor. It has been speculated that having multiple AHRs contributes to the very high sensitivity of salmonid species to TCDD and related chemicals. To test the hypothesis that all four salmon AHR2 proteins are expressed and functional, we measured mRNA transcription for each AHR2 in several tissues, cloned the cDNAs and evaluated the functional properties of the expressed proteins. Analysis by real-time PCR revealed that the receptors showed differences in transcript levels among salmon tissues and that in general AHR2alpha was transcribed at higher levels than the other three AHR2s. Velocity sedimentation analysis showed that all four in vitro-expressed AHR2 proteins exhibit specific, high-affinity binding of [(3)H]TCDD. When expressed in COS-7 cells, all four AHR2 proteins were able to drive the expression of a reporter gene under control of murine CYP1A1 enhancer elements. From EC(50) values determined in TCDD concentration-response experiments, all four salmon AHR2s show similar sensitivity to TCDD. In summary, all four Atlantic salmon AHR2 appear to function in AHR-mediated signaling, suggesting that all four proteins are involved in TCDD-mediated toxicity. |
format |
Article in Journal/Newspaper |
author |
Hansson, Maria Hahn, Mark E |
author_facet |
Hansson, Maria Hahn, Mark E |
author_sort |
Hansson, Maria |
title |
Functional properties of the four Atlantic salmon (Salmo salar) aryl hydrocarbon receptor type 2 (AHR2) isoforms. |
title_short |
Functional properties of the four Atlantic salmon (Salmo salar) aryl hydrocarbon receptor type 2 (AHR2) isoforms. |
title_full |
Functional properties of the four Atlantic salmon (Salmo salar) aryl hydrocarbon receptor type 2 (AHR2) isoforms. |
title_fullStr |
Functional properties of the four Atlantic salmon (Salmo salar) aryl hydrocarbon receptor type 2 (AHR2) isoforms. |
title_full_unstemmed |
Functional properties of the four Atlantic salmon (Salmo salar) aryl hydrocarbon receptor type 2 (AHR2) isoforms. |
title_sort |
functional properties of the four atlantic salmon (salmo salar) aryl hydrocarbon receptor type 2 (ahr2) isoforms. |
publisher |
Elsevier |
publishDate |
2008 |
url |
https://lup.lub.lu.se/record/1035559 https://doi.org/10.1016/j.aquatox.2007.10.012 |
genre |
Atlantic salmon Salmo salar |
genre_facet |
Atlantic salmon Salmo salar |
op_source |
Aquatic Toxicology; 86(2), pp 121-130 (2008) ISSN: 1879-1514 |
op_relation |
https://lup.lub.lu.se/record/1035559 http://dx.doi.org/10.1016/j.aquatox.2007.10.012 pmid:18063141 wos:000253696200001 scopus:38549166269 |
op_doi |
https://doi.org/10.1016/j.aquatox.2007.10.012 |
container_title |
Aquatic Toxicology |
container_volume |
86 |
container_issue |
2 |
container_start_page |
121 |
op_container_end_page |
130 |
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1766360970873012224 |