title: Glutathione S-Transferase (GST) Gene Diversity in the Crustacean Calanus finmarchicus--Contributors to Cellular Detoxification.
abstract: Detoxification is a fundamental cellular stress defense mechanism, which allows an organism to survive or even thrive in the presence of environmental toxins and/or pollutants. The glutathione S-transferase (GST) superfamily is a set of enzymes involved in the detoxification process. This highly diverse protein superfamily is characterized by multiple gene duplications, with over 40 GST genes reported in some insects. However, less is known about the GST superfamily in marine organisms, including crustaceans. The availability of two de novo transcriptomes for the copepod, Calanus finmarchicus, provided an opportunity for an in depth study of the GST superfamily in a marine crustacean. The transcriptomes were searched for putative GST-encoding transcripts using known GST proteins from three arthropods as queries. The identified transcripts were then translated into proteins, analyzed for structural domains, and annotated using reciprocal BLAST analysis. Mining the two transcriptomes yielded a total of 41 predicted GST proteins belonging to the cytosolic, mitochondrial or microsomal classes. Phylogenetic analysis of the cytosolic GSTs validated their annotation into six different subclasses. The predicted proteins are likely to represent the products of distinct genes, suggesting that the diversity of GSTs in C. finmarchicus exceeds or rivals that described for insects. Analysis of relative gene expression in different developmental stages indicated low levels of GST expression in embryos, and relatively high expression in late copepodites and adult females for several cytosolic GSTs. A diverse diet and complex life history are factors that might be driving the multiplicity of GSTs in C. finmarchicus, as this copepod is commonly exposed to a variety of natural toxins. Hence, diversity in detoxification pathway proteins may well be key to their survival.
authors.affiliation: Békésy Laboratory of Neurobiology, Pacific Biosciences Research Center, University of Hawaii at Manoa, Honolulu, Hawaii, United States of America.
authors.forename: Vittoria
authors.initials: V
authors.lastname: Roncalli
authors.affiliation: Békésy Laboratory of Neurobiology, Pacific Biosciences Research Center, University of Hawaii at Manoa, Honolulu, Hawaii, United States of America.
authors.forename: Matthew C
authors.initials: MC
authors.lastname: Cieslak
authors.affiliation: Kewalo Marine Laboratory, Pacific Biosciences Research Center, University of Hawaii at Manoa, Honolulu, Hawaii, United States of America.
authors.forename: Yale
authors.initials: Y
authors.lastname: Passamaneck
authors.affiliation: Békésy Laboratory of Neurobiology, Pacific Biosciences Research Center, University of Hawaii at Manoa, Honolulu, Hawaii, United States of America.
authors.forename: Andrew E
authors.initials: AE
authors.lastname: Christie
authors.affiliation: Békésy Laboratory of Neurobiology, Pacific Biosciences Research Center, University of Hawaii at Manoa, Honolulu, Hawaii, United States of America.
authors.forename: Petra H
authors.initials: PH
authors.lastname: Lenz
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D060829:Arthropod Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D003445:Crustacea / Q000201:enzymology / Q000235:genetics*; D003593:Cytoplasm / Q000201:enzymology; D014644:Genetic Variation; D005982:Glutathione Transferase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D008861:Microsomes / Q000201:enzymology; D008928:Mitochondria / Q000201:enzymology; D008969:Molecular Sequence Data; D010802:Phylogeny; D059467:Transcriptome
chemical_list: D060829:Arthropod Proteins; D007527:Isoenzymes; D005982:Glutathione Transferase