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Expression, Solubilization, and Purification of Eukaryotic Borate Transporters
Published on: March 7, 2019
Jen1p: a high affinity selenite transporter in yeast
Joseph R McDermott1, Barry P Rosen, Zijuan Liu
1Department of Biological Sciences, Oakland University, Rochester, MI 48309, USA.
Molecular Biology of the Cell
|September 24, 2010
Summary
The yeast transporter Jen1p facilitates the uptake of selenite, a crucial micronutrient. This discovery reveals selenite mimics monocarboxylates, impacting its transport and cellular accumulation.
Area of Science:
- Biochemistry
- Molecular Biology
- Cell Biology
Background:
- Selenium is an essential micronutrient with a narrow window between beneficial and toxic levels.
- Selenite is the primary environmental and therapeutic form of selenium, necessitating controlled cellular uptake.
- Efficient transport systems are vital for acquiring selenium and preventing toxicity.
Purpose of the Study:
- To identify the specific transporter responsible for selenite uptake in *Saccharomyces cerevisiae* (yeast).
- To elucidate the mechanism by which selenite enters yeast cells.
- To investigate the relationship between selenite and known monocarboxylate transporters.
Main Methods:
- Genetic analysis of *JEN1* gene disruption and overexpression in yeast.
- Selenite transport assays to measure uptake rates and kinetics.
- Competitive inhibition studies using lactate to assess transporter specificity.
Main Results:
- The proton-coupled monocarboxylate transporter Jen1p was identified as a high-affinity selenite transporter.
- Disruption of *JEN1* conferred selenite resistance, while overexpression led to hypersensitivity.
- Jen1p facilitated selenite accumulation in yeast cells, with kinetics similar to lactate transport.
- Selenite and lactate competitively inhibited each other's transport, suggesting molecular mimicry.
Conclusions:
- Jen1p is a key transporter for selenite uptake in yeast.
- Selenite acts as a molecular mimic of monocarboxylates, utilizing the Jen1p transporter.
- This finding provides insights into selenium homeostasis and potential therapeutic strategies.
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