Characterization and metal-induced gene transcription of two new copper zinc superoxide dismutases in the solitary ascidian Ciona intestinalis.
Aquat Toxicol
; 140-141: 369-79, 2013 Sep 15.
Article
em En
| MEDLINE
| ID: mdl-23891785
ABSTRACT
Antioxidant enzymes are known to protect living organisms against the oxidative stress risk, also induced by metals. In the present study, we describe the purification and molecular characterization of two Cu,Zn superoxide dismutases (SODs), referred to as Ci-SODa and Ci-SODb, from Ciona intestinalis, a basal chordate widely distributed in temperate shallow seawater. The putative amino acid sequences were compared with Cu,Zn SODs from other metazoans and phylogenetic analyses indicate that the two putative Ci-SODs are more related to invertebrate SODs than vertebrate ones. Both phylogenetic and preliminary homology modeling analyses suggest that Ci-SODa and Ci-SODb are extracellular and intracellular isoform, respectively. The mRNA of the two Cu,Zn SODs was localized in hemocytes and in ovarian follicular cells, as revealed by in situ hybridization. The time course of SOD mRNA levels in the presence of three different metals showed upregulation of ci-soda and inhibition of ci-sodb. Spectrophotometric analysis confirms the presence of SOD activity in Ciona tissues. Our in silico analyses of the ci-soda promoter region revealed putative consensus sequences similar to mammalian metal-responsive elements (MRE), suggesting that the transcription of these genes directly depends on metals. These data emphasize the importance of complex metal regulation of ci-soda and ci-sodb transcription, as components of an efficient detoxification pathway allowing the survival of C. intestinalis in continued, elevated presence of metals in the environment.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Superóxido Dismutase
/
Poluentes Químicos da Água
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Regulação Enzimológica da Expressão Gênica
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Ciona intestinalis
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Metais
Limite:
Animals
Idioma:
En
Revista:
Aquat Toxicol
Assunto da revista:
BIOLOGIA
/
TOXICOLOGIA
Ano de publicação:
2013
Tipo de documento:
Article
País de afiliação:
Itália