title: cDNA cloning and expression analysis of the catalytic subunit of glutamate cysteine ligase gene in an annelid polychaete after cadmium exposure: a potential tool for pollution biomonitoring.
abstract: The enzyme glutamate cysteine ligase (GCL) is the rate-limiting enzyme in glutathione (GSH) synthesis and is formed by a catalytic (GCLC) and a modulatory subunit (GCLM). Some studies have demonstrated that environmental pollutants can regulate the expression of these subunits. Despite the importance of these genes in toxicological responses, no sequences are available for the GCL subunits in annelids. The present study reports, for the first time, the cDNA sequence for the GCLC in an annelid species, the polychaete Laeonereis acuta (Nereididae). The deduced amino acid sequence of L. acuta GCLC showed homology with other animal species, and was used to infer a phylogenetic tree with GCLC amino acid sequences from other taxonomic groups. Exposure to cadmium (100 and 1000 microg Cd/L) during 14 days augmented the level of L. acuta GCLC transcripts in a dose-dependent manner. These gene expression results can be related to the known cadmium effect on GSH depletion. Since a number of contaminants can also exert their toxicity through this mechanism, GCLC gene expression might be applied not only for cadmium biomonitoring, but also for a wide range of contaminants that directly or indirectly promote the same effect in the cellular GSH content.
authors.affiliation: Departamento de Ciências Fisiológicas, Fundação Universidade Federal do Rio Grande (FURG), Caixa Postal 474, CEP 96201-900, Rio Grande, RS, Brazil.
authors.forename: Juliana Z
authors.initials: JZ
authors.lastname: Sandrini
authors.forename: Jomar
authors.initials: J
authors.lastname: Laurino
authors.forename: Terumi
authors.initials: T
authors.lastname: Hatanaka
authors.forename: José M
authors.initials: JM
authors.lastname: Monserrat
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015415:Biomarkers / Q000032:analysis; D002104:Cadmium / Q000494:pharmacology*; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D004784:Environmental Monitoring / Q000379:methods; D004785:Environmental Pollutants / Q000032:analysis; D015870:Gene Expression / Q000187:drug effects; D005721:Glutamate-Cysteine Ligase / Q000235:genetics*; D008969:Molecular Sequence Data; D010802:Phylogeny; D011077:Polychaeta / Q000187:drug effects* / Q000235:genetics*
chemical_list: D015415:Biomarkers; D018076:DNA, Complementary; D004785:Environmental Pollutants; D002104:Cadmium; D005721:Glutamate-Cysteine Ligase