title: Cloning and expression analysis of Drosophila extracellular Cu Zn superoxide dismutase.
abstract: In the present study, we cloned and sequenced the mRNAs of the Sod3 [extracellular Cu Zn SOD (superoxide dismutase)] gene in Drosophila and identified two mRNA products formed by alternative splicing. These products code for a long and short protein derived from the four transcripts found in global expression studies (Flybase numbers Dmel\CG9027, FBgn0033631). Both mRNA process variants contain an extracellular signalling sequence, a region of high homology to the Sod1 (cytoplasmic Cu Zn SOD) including a conserved AUG start, with the longer form also containing a hydrophobic tail. The two fully processed transcripts are homologous to Caenorhabditis elegans Sod3 mRNA showing the same processing pattern. Using an established KG p-element+ insertion line (KG06029), we demonstrate that the Sod3 codes for an active Cu Zn SOD. We found differing expression patterns across sex with higher levels of expression of Sod3 in females. There is a correlation of Sod1 and Sod3 gene expression and activity that can explain why Sod3 was not seen in earlier studies of Sod1. Finally, we found no effect on lifespan with the Sod3 hypomorph mutation (Sod3KG06029) but did observe a significant increase in resistance to paraquat and H2O2 (hydrogen peroxide).
authors.affiliation: *School of Biological Sciences, University of Southampton, Life Sciences Building 85, Highfield Campus, Southampton SO17 1BJ, U.K.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Blackney
authors.affiliation: *School of Biological Sciences, University of Southampton, Life Sciences Building 85, Highfield Campus, Southampton SO17 1BJ, U.K.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Cox
authors.affiliation: *School of Biological Sciences, University of Southampton, Life Sciences Building 85, Highfield Campus, Southampton SO17 1BJ, U.K.
authors.forename: David
authors.initials: D
authors.lastname: Shepherd
authors.affiliation: *School of Biological Sciences, University of Southampton, Life Sciences Building 85, Highfield Campus, Southampton SO17 1BJ, U.K.
authors.forename: Joel D
authors.initials: JD
authors.lastname: Parker
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D003001:Cloning, Molecular; D029721:Drosophila Proteins / Q000235:genetics* / Q000378:metabolism; D004331:Drosophila melanogaster / Q000187:drug effects / Q000201:enzymology / Q000235:genetics*; D005110:Extracellular Space / Q000201:enzymology; D005260:Female; D015971:Gene Expression Regulation, Enzymologic; D006540:Herbicides / Q000494:pharmacology; D006861:Hydrogen Peroxide / Q000494:pharmacology; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D008297:Male; D008969:Molecular Sequence Data; D009154:Mutation; D016877:Oxidants / Q000494:pharmacology; D010269:Paraquat / Q000494:pharmacology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D012737:Sex Factors; D013482:Superoxide Dismutase / Q000235:genetics* / Q000378:metabolism; D016019:Survival Analysis
chemical_list: D029721:Drosophila Proteins; D006540:Herbicides; D007527:Isoenzymes; D016877:Oxidants; D006861:Hydrogen Peroxide; D013482:Superoxide Dismutase; D010269:Paraquat