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Overview of metallothionein (MT) gene regulation and function. The MT promoter has many response elements that upregulate transcription. These include the following: (1) metal response elements (MRE), which are activated by the metal-responsive transcription factor (MTF-1) after zinc occupancy, which is a function of the dietary zinc supply; (2) glucocorticoid response elements (GRE); (3) elements activated by STAT (signal transducers and activators of transcription) proteins through cytokine signaling; and 4) the antioxidant (or electrophile) response element (ARE), activated in response to redox status. Methylation may downregulate expression in some tumor cells. Cellular zinc pools are influenced by dietary zinc intake and zinc transporter activity and serve as the source of zinc bound to MT. Zinc bound to MT exhibits high thermodynamic stability. Apo-MT (thionein) and Zn 7 -MT (all coordination sites occupied) may serve to 

Overview of metallothionein (MT) gene regulation and function. The MT promoter has many response elements that upregulate transcription. These include the following: (1) metal response elements (MRE), which are activated by the metal-responsive transcription factor (MTF-1) after zinc occupancy, which is a function of the dietary zinc supply; (2) glucocorticoid response elements (GRE); (3) elements activated by STAT (signal transducers and activators of transcription) proteins through cytokine signaling; and 4) the antioxidant (or electrophile) response element (ARE), activated in response to redox status. Methylation may downregulate expression in some tumor cells. Cellular zinc pools are influenced by dietary zinc intake and zinc transporter activity and serve as the source of zinc bound to MT. Zinc bound to MT exhibits high thermodynamic stability. Apo-MT (thionein) and Zn 7 -MT (all coordination sites occupied) may serve to 

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Free radicals are chemical particles containing one or more unpaired electrons, which may be part of the molecule. They cause the molecule to become highly reactive. The free radicals are also known to play a dual role in biological systems, as they can be either beneficial or harmful for living systems. It is clear that there are numerous mechanis...

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... gene expression and activity of proteins, such as metalloproteins and metal-dependent transcription factors, as shown in Figure 2 and discussed in the following papers [79,80]. The binding of zinc to MTs is thermodynamically stable, which makes MTs an ideal zinc reservoir in vivo . The question is how MTs make zinc available for other molecules, including transcription factors and metalloproteins. Maret et al. [76] showed that there is fast zinc exchange between MT isoforms 1 and 2 and also between MT2 and the zinc cluster in the Gal4 transcription factor [76]. Moreover, Jacob et al. found zinc transfer between MT and the apo-forms of zinc proteins E. coli alkaline phosphatase and bovine carboxypeptidase A [80]. Reduced glutathione (GSH) and glutathione disulfide (GSSG) are critical modulators of both the rate of zinc transfer and the ultimate number of zinc atoms transferred [79,81,82]. GSH inhibits zinc release in the absence of GSSG, indicating that MT is stabilized at relatively high cellular GSH concentrations. The presence of GSSG results in zinc release ...

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... Findings of the laboratory challenge also suggest that the oxidative stress response in Pacific oysters may be at least partially shaped by culture treatment. Temperature and culture treatment had a significant interactive effect on the expression of MT, a metal-binding protein that participates in a range of protective stress responses (Ruttkay-Nedecky et al. 2013), and Gpx, an antioxidant enzyme that combats ROS accumulation and is thus associated with aerobic recovery in bivalves (Pannunzio and Storey 1998;Trevisan et al. 2014). ...
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