کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2570097 1128568 2010 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Perchlorate transport and inhibition of the sodium iodide symporter measured with the yellow fluorescent protein variant YFP-H148Q/I152L
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم محیط زیست بهداشت، سم شناسی و جهش زایی
پیش نمایش صفحه اول مقاله
Perchlorate transport and inhibition of the sodium iodide symporter measured with the yellow fluorescent protein variant YFP-H148Q/I152L
چکیده انگلیسی

Perchlorate is an environmental contaminant that impairs thyroid function by interacting with the sodium iodide symporter (NIS), the transporter responsible for iodide uptake in the thyroid gland. Perchlorate is well known as a competitive inhibitor of iodide transport by NIS, and recent evidence demonstrates that NIS can also transport perchlorate. In this study, we evaluated the yellow fluorescent protein (YFP) variant YFP-H148Q/I152L, as a genetically encodable biosensor of intracellular perchlorate concentration monitored by real-time fluorescence microscopy. Fluorescence of recombinant YFP-H148Q/I152L was suppressed by perchlorate and iodide with similar affinities of 1.2 mM and 1.6 mM, respectively. Perchlorate suppressed YFP-H148Q/I152L fluorescence in FRTL-5 thyroid cells and NIS-expressing COS-7 cells, but had no effect on COS-7 cells lacking NIS. Fluorescence changes in FRTL-5 cells were Na+-dependent, consistent with the Na+-dependence of NIS activity. Perchlorate uptake in FRTL-5 cells resulted in 10-fold lower intracellular concentrations than iodide uptake, and was characterized by a higher affinity (Km 4.6 μM for perchlorate and 34.8 μM for iodide) and lower maximal velocity (Vmax 6.8 μM/s for perchlorate and 39.5 μM/s for iodide). Perchlorate also prevented iodide-induced changes in YFP-H148Q/I152L fluorescence in FRTL-5 cells, with half-maximal inhibition occurring at 1.1–1.6 μM. In conclusion, YFP-H148Q/I152L detects perchlorate accumulation by thyroid and other NIS-expressing cells, and reveals differences in the kinetics of perchlorate versus iodide transport by NIS.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Toxicology and Applied Pharmacology - Volume 243, Issue 3, 15 March 2010, Pages 372–380
نویسندگان
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