title: Deiodinase type III in the Australian lungfish, Neoceratodus forsteri.
abstract: This work presents characterisation of deiodinase type III (D3) mRNA as cDNA and the tissue distribution of D3 mRNA in the Australian lungfish, Neoceratodus forsteri. We have identified the full length of a approximately 1.4 kb D3 mRNA in the liver, which has a single in-frame UGA codon and a selenocysteine insertion sequence (SECIS) form 2 in the 3'-UTR. Lungfish D3 mRNA was expressed in all tested tissues (liver, lung, kidney, brain, heart, and gills) as demonstrated by Northern blot analyses. PCR conducted on genomic DNA indicated that the lungfish D3 is a single exon gene. Also, we present enzymatic characteristics of this exclusively IRD enzyme, have determined its substrate preference, DTT cofactor requirements, PTU inhibition, and kinetic properties. These results indicate that lungfish D3 has the typical enzymatic characteristics of vertebrate D3 enzymes.
authors.affiliation: Department of Biological Sciences, Macquarie University, NSW 2109, Australia. msutija@rna.bio.mq.edu.au
authors.forename: Margareta
authors.initials: M
authors.lastname: Sutija
authors.forename: Terrence J
authors.initials: TJ
authors.lastname: Longhurst
authors.forename: Jean M P
authors.initials: JM
authors.lastname: Joss
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D001921:Brain / Q000201:enzymology; D018076:DNA, Complementary / Q000032:analysis; D005399:Fishes / Q000378:metabolism*; D005880:Gills / Q000201:enzymology; D007453:Iodide Peroxidase / Q000032:analysis* / Q000235:genetics; D007668:Kidney / Q000201:enzymology; D008099:Liver / Q000201:enzymology; D008168:Lung / Q000201:enzymology; D008862:Microsomes, Liver / Q000201:enzymology; D008969:Molecular Sequence Data; D009206:Myocardium / Q000201:enzymology; D009928:Organ Specificity; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment
chemical_list: D018076:DNA, Complementary; D012333:RNA, Messenger; D007453:Iodide Peroxidase