Precise control of gene expression is a powerful method to elucidate biological function, and protein overexpression is an important tool for industry and biochemistry. Expression of the Neurospora crassa tcu-1 gene (NCU00830), encoding a high-affinity copper transporter, is tightly controlled by copper availability. Excess copper represses, and copper depletion, via the use of a copper chelato...

Copper is essential for all living organisms but is toxic when present in excess. Therefore organisms have developed homeostatic mechanism to tightly regulate its cellular concentration. In a recent study we have shown that CopRS two-component system is essential for copper resistance in the cyanobacterium Synechocystis sp PCC 6803. This two-component regulates expression of a heavy-metal RND t...

Copper is essential but toxic in excess for aerobic organisms. Yeast transcription factor ACE1 functions as a sensor for copper and an inducer for the transcription of CUP1. In addition, ACE1 can activate the transcription of superoxide dismutase gene (sod1) in response to copper. In this study, we introduced the yeast ACE1 into Arabidopsis and analyzed its function in plant. Under high copper ...

The distribution of copper in Sprague - Dawley rats following a three month oral administration of 0,10 or 50mg/kg copper aspirinate has been investigated. Metal content was determined by ICP - AES in blood, brain, kidney, liver, lung, spleen, and dejection. The results show that treatment with copper aspirinate did not cause accumulation of copper in rats and excess ingested copper was excrete...

The CO preferential oxidation (PrOx) is one of the critical steps in hydrogen production and purification for Polymer Electrolyte Membrane Fuel Cell (PEMFC). This reaction was investigated in the presence of excess hydrogen over Cu/CeO2, Pt/CeO2 and Cu-Pt/CeO2 catalysts. The ceria supports was prepared via precipitation method and Cu-Pt/CeO2 catalyst was synthesized by sequential impregnation o...

Copper is an essential transition metal but is toxic in excess; therefore, its metabolism needs to be tightly regulated. Defects in the regulation of copper can lead to various disorders characterized by copper deficiency or copper excess. Recently, we characterized the COMMD1 (previously MURR1) gene as the defective gene in canine copper toxicosis. The molecular functions of COMMD1 remain unkn...

the micro-segregation in binary al-cu alloys containing 2.2, 3.7, and 4.8 wt.% copper was investigated by differential thermal analysis (dta) and numerical modeling. for this purpose, the alloys were melted using a dta furnace with the capability of quenching samples during solidification. the melted samples were cooled at 0.008 and 0.083 k/s and subsequently quenched from predetermined tempera...

Copper and iron are essential but also toxic metals. Their essentiality is known, but their toxicity, except for the genetic overload diseases, Wilson's disease and hemochromatosis, is not so well known. Yet, their toxicities are so general in the population that they are a looming public health problem in diseases of aging and in the aging process itself. Both metals are transition elements, a...

Copper complexation in marine systems is mainly controlled by organic matter, partially produced by micro- and macroalgae that release exudates with the capacity to bind metals. This feature is important as it influences bioavailability, bioaccumulation, toxicity, and transport of copper through biological membranes. The release of Cu-complexing ligands by seaweeds cultured under copper excess ...

The level at which copper becomes toxic is not clear. Several studies have indicated that copper causes oxidative stress; however, most have tested very high levels of copper exposure. We currently have only a limited understanding of the protective systems that operate in cells chronically exposed to copper. Additionally, the limits of homeostatic regulation are not known, making it difficult ...