Click here to close
Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly.
We suggest using a current version of Chrome,
FireFox, or Safari.
Proc Natl Acad Sci U S A
1994 Aug 02;9116:7767-71.
Show Gene links
Show Anatomy links
A thyroid hormone-regulated gene in Xenopus laevis encodes a type III iodothyronine 5-deiodinase.
St Germain DL
,
Schwartzman RA
,
Croteau W
,
Kanamori A
,
Wang Z
,
Brown DD
,
Galton VA
.
???displayArticle.abstract???
The type III iodothyronine 5-deiodinase metabolizes thyroxine and 3,5,3'-triiodothyronine to inactive metabolites by catalyzing the removal of iodine from the inner ring. The enzyme is expressed in a tissue-specific pattern during particular stages of development in amphibia, birds, and mammals. Recently, a PCR-based subtractive hybridization technique has been used to isolate cDNAs prepared from Xenopus laevis tadpole tail mRNA that represent genes upregulated by thyroid hormone during metamorphosis. Sequence analysis of one of these cDNAs (XL-15) revealed regions of homology to the mRNA encoding the rat type I (outer ring) 5'-deiodinase, including a conserved UGA codon that encodes selenocysteine in the mammalian enzyme. We report here that the protein encoded by the XL-15 cDNA efficiently catalyzes the (inner ring) 5-deiodination of 3,5,3'-triiodothyronine with a Km value of 2 nM and is resistant to inhibition by propylthiouracil and aurothioglucose. Our analysis confirms that the UGA codon encodes a selenocysteine that is critical for the catalytic activity of the enzyme. In addition, the direct induction of XL-15 mRNA levels by thyroid hormone in X. laevis tadpole tail tissue and cultured cell lines correlates closely with increases in 5- (but not 5'-) deiodinase activity. These findings indicate that the XL-15 cDNA encodes a type III 5-deiodinase and underscores the importance of the trace element selenium in thyroid hormone metabolism.
Berry,
Type I iodothyronine deiodinase is a selenocysteine-containing enzyme.
1991, Pubmed,
Xenbase
Berry,
Type I iodothyronine deiodinase is a selenocysteine-containing enzyme.
1991,
Pubmed
,
Xenbase
Berry,
Evidence that cysteine, not selenocysteine, is in the catalytic site of type II iodothyronine deiodinase.
1991,
Pubmed
Berry,
Selenocysteine confers the biochemical properties characteristic of the type I iodothyronine deiodinase.
1991,
Pubmed
,
Xenbase
Berry,
Identification of essential histidine residues in rat type I iodothyronine deiodinase.
1992,
Pubmed
Berry,
Functional characterization of the eukaryotic SECIS elements which direct selenocysteine insertion at UGA codons.
1993,
Pubmed
Bradford,
A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding.
1976,
Pubmed
Buckbinder,
Thyroid hormone-induced gene expression changes in the developing frog limb.
1992,
Pubmed
,
Xenbase
Galton,
Putative nuclear triiodothyronine receptors in tadpole liver during metamorphic climax.
1985,
Pubmed
Galton,
The ontogeny of the enzyme systems for the 5'- and 5-deiodination of thyroid hormones in chick embryo liver.
1987,
Pubmed
Galton,
The ontogeny of iodothyronine deiodinase systems in liver and intestine of the rat.
1991,
Pubmed
Kanamori,
Cultured cells as a model for amphibian metamorphosis.
1993,
Pubmed
,
Xenbase
Mol,
Different thyroid hormone-deiodinating enzymes in tilapia (Oreochromis niloticus) liver and kidney.
1993,
Pubmed
Safran,
Evidence that type II 5'-deiodinase is not a selenoprotein.
1991,
Pubmed
Samuels,
Depletion of L-3,5,3'-triiodothyronine and L-thyroxine in euthyroid calf serum for use in cell culture studies of the action of thyroid hormone.
1979,
Pubmed
Santini,
A study of the characteristics of the rat placental iodothyronine 5-monodeiodinase: evidence that it is distinct from the rat hepatic iodothyronine 5'-monodeiodinase.
1992,
Pubmed
Sharifi,
The cDNA for the type I iodothyronine 5'-deiodinase encodes an enzyme manifesting both high Km and low Km activity. Evidence that rat liver and kidney contain a single enzyme which converts thyroxine to 3,5,3'-triiodothyronine.
1992,
Pubmed
,
Xenbase
St Germain,
The effects and interactions of substrates, inhibitors, and the cellular thiol-disulfide balance on the regulation of type II iodothyronine 5'-deiodinase.
1988,
Pubmed
St Germain,
Expression of phenolic and tyrosyl ring iodothyronine deiodinases in Xenopus laevis oocytes is dependent on the tissue source of injected poly(A)+ RNA.
1989,
Pubmed
,
Xenbase
St Germain,
A thyroid hormone-regulated gene in Xenopus laevis encodes a type III iodothyronine 5-deiodinase.
1994,
Pubmed
,
Xenbase
Visser,
Characteristics of type III iodothyronine deiodinase.
1992,
Pubmed
Wang,
Thyroid hormone-induced gene expression program for amphibian tail resorption.
1993,
Pubmed
,
Xenbase
Wang,
A gene expression screen.
1991,
Pubmed
,
Xenbase
