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Gen Comp Endocrinol
2008 Mar 01;1561:9-14. doi: 10.1016/j.ygcen.2008.01.005.
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A perchlorate sensitive iodide transporter in frogs.
Carr DL
,
Carr JA
,
Willis RE
,
Pressley TA
.
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Nucleotide sequence comparisons have identified a gene product in the genome database of African clawed frogs (Xenopus laevis) as a probable member of the solute carrier family of membrane transporters. To confirm its identity as a putative iodide transporter, we examined the function of this sequence after heterologous expression in mammalian cells. A green monkey kidney cell line transfected with the Xenopus nucleotide sequence had significantly greater (125)I uptake than sham-transfected control cells. The uptake in carrier-transfected cells was significantly inhibited in the presence of perchlorate, a competitive inhibitor of mammalian Na(+)/iodide symporter. Tissue distributions of the sequence were also consistent with a role in iodide uptake. The mRNA encoding the carrier was found to be expressed in the thyroid gland, stomach, and kidney of tadpoles from X. laevis, as well as the bullfrog Rana catesbeiana. The ovaries of adult X. laevis also were found to express the carrier. Phylogenetic analysis suggested that the putative X. laevis iodide transporter is orthologous to vertebrate Na(+)-dependent iodide symporters. We conclude that the amphibian sequence encodes a protein that is indeed a functional Na(+)/iodide symporter in X. laevis, as well as R. catesbeiana.
Fig. 1.
RT-PCR analysis of the xNIS mRNA in different tissues of X. laevis (NF stage 58) and R. catesbeiana (Taylor–Kollros stages XVII–XX) tadpoles. Adult male and female X. laevis were used for analysis of testicular and ovarian tissue, respectively. Two micrograms of total RNA from thyroid, kidney, GI tract, skeletal muscle, brain, liver, or adult testes and ovaries were reversed transcribed before PCR amplification and separation on a 2% gel (1% agarose, 1% Nusieve, BioWhittaker Molecular Applications) for low molecular weight resolution. Relative expression of the ribosomal protein L8 (RPL8) is shown as a housekeeping control for the integrity of the total RNA.
Fig. 2.
In vitro125I uptake in the presence or absence of perchlorate (20 μM) by COS cells transfected with xNIS or the negative control, GFP-tagged α subunit from the Na+,K+-ATPase (Sham). Bars represents means ± SEM of 18 independent experiments.
Fig. 3.
Phylogenetic analysis of selected solute carrier proteins using the neighbor-joining method. Tree shown was derived from 686 positions using the complete deletion option and nodal support was determined using 1000 bootstrap replications. Scale bar indicates number of amino acid substitutions per site. Solute carrier proteins used in this analysis are NIS (Na+-dependent I− symporter); SGLT1 (Na(+)/glucose cotransporter); SMCTe (electrogenic sodium monocarboxylic acid transporter).
Carr,
Molecular characterization of a putative sodium/iodide symporter in the South African clawed frog, Xenopus laevis.
2003, Pubmed,
Xenbase
Carr,
Molecular characterization of a putative sodium/iodide symporter in the South African clawed frog, Xenopus laevis.
2003,
Pubmed
,
Xenbase
Castro,
Development of monoclonal antibodies against the human sodium iodide symporter: immunohistochemical characterization of this protein in thyroid cells.
1999,
Pubmed
Coady,
The human tumour suppressor gene SLC5A8 expresses a Na+-monocarboxylate cotransporter.
2004,
Pubmed
,
Xenbase
Dai,
Cloning and characterization of the thyroid iodide transporter.
1996,
Pubmed
,
Xenbase
De La Vieja,
Molecular analysis of the sodium/iodide symporter: impact on thyroid and extrathyroid pathophysiology.
2000,
Pubmed
Felsenstein,
CONFIDENCE LIMITS ON PHYLOGENIES: AN APPROACH USING THE BOOTSTRAP.
1985,
Pubmed
Goleman,
Environmentally relevant concentrations of ammonium perchlorate inhibit thyroid function and alter sex ratios in developing Xenopus laevis.
2002,
Pubmed
,
Xenbase
Goleman,
Environmentally relevant concentrations of ammonium perchlorate inhibit development and metamorphosis in Xenopus laevis.
2002,
Pubmed
,
Xenbase
Goleman,
Contribution of ammonium ions to the lethality and antimetamorphic effects of ammonium perchlorate.
2006,
Pubmed
,
Xenbase
Hu,
The colloidal thyroxine (T4) ring as a novel biomarker of perchlorate exposure in the African clawed frog Xenopus laevis.
2006,
Pubmed
,
Xenbase
Kumar,
MEGA3: Integrated software for Molecular Evolutionary Genetics Analysis and sequence alignment.
2004,
Pubmed
LOWRY,
Protein measurement with the Folin phenol reagent.
1951,
Pubmed
Lacroix,
Na(+)/I(-) symporter and Pendred syndrome gene and protein expressions in human extra-thyroidal tissues.
2001,
Pubmed
Marians,
Defining thyrotropin-dependent and -independent steps of thyroid hormone synthesis by using thyrotropin receptor-null mice.
2002,
Pubmed
Miyauchi,
Functional identification of SLC5A8, a tumor suppressor down-regulated in colon cancer, as a Na(+)-coupled transporter for short-chain fatty acids.
2004,
Pubmed
,
Xenbase
Newcomer,
Hormonal regulation of iodine accumulation in ovary and thyroid of Japanese quail.
1982,
Pubmed
Ohmori,
A novel thyroid transcription factor is essential for thyrotropin-induced up-regulation of Na+/I- symporter gene expression.
1998,
Pubmed
Opitz,
Expression of sodium-iodide symporter mRNA in the thyroid gland of Xenopus laevis tadpoles: developmental expression, effects of antithyroidal compounds, and regulation by TSH.
2006,
Pubmed
,
Xenbase
Paroder,
Na(+)/monocarboxylate transport (SMCT) protein expression correlates with survival in colon cancer: molecular characterization of SMCT.
2006,
Pubmed
,
Xenbase
Pressley,
Stimulation of Na(+)-K(+)-ATPase by thyrotropin in cultured thyroid follicular cells.
1995,
Pubmed
Rodriguez,
Identification and characterization of a putative human iodide transporter located at the apical membrane of thyrocytes.
2002,
Pubmed
Saitou,
The neighbor-joining method: a new method for reconstructing phylogenetic trees.
1987,
Pubmed
Slebodziński,
Ovarian iodide uptake and triiodothyronine generation in follicular fluid. The enigma of the thyroid ovary interaction.
2005,
Pubmed
Sparling,
Comparative toxicity of ammonium and perchlorate to amphibians.
2006,
Pubmed
Spitzweg,
Expression of the sodium iodide symporter in human kidney.
2001,
Pubmed
TAYLOR,
Stages in the normal development of Rana pipiens larvae.
1946,
Pubmed
Theodorakis,
Thyroid endocrine disruption in stonerollers and cricket frogs from perchlorate-contaminated streams in east-central Texas.
2006,
Pubmed
Thompson,
CLUSTAL W: improving the sensitivity of progressive multiple sequence alignment through sequence weighting, position-specific gap penalties and weight matrix choice.
1994,
Pubmed
Wapnir,
Immunohistochemical profile of the sodium/iodide symporter in thyroid, breast, and other carcinomas using high density tissue microarrays and conventional sections.
2003,
Pubmed
Weiss,
Iodide transport in a continuous line of cultured cells from rat thyroid.
1984,
Pubmed
Wright,
Influence of cortisol on the larval bullfrog thyroid axis in vitro and in vivo and on plasma and ocular melatonin.
1999,
Pubmed
