Functional and physical interaction between the selenium-binding protein 1 (SBP1) and the glutathione peroxidase 1 selenoprotein

Abstract

Selenium-binding protein (SBP) 1 is present in reduced levels in several cancer types as compared with normal tissues, and lower levels are associated with poor clinical prognosis. Another selenium-containing protein, glutathione peroxidase 1 (GPX1), has been associated with cancer risk and development. The interaction between these representatives of different classes of selenoproteins was investigated. Increasing SBP1 levels in either human colorectal or breast cancer cells by transfection of an expression construct resulted in the reduction of GPX1 enzyme activity. Increased expression of GPX1 in the same cell types resulted in the transcriptional and translational repression of SBP1, as evidenced by the reduction of SBP1 messenger RNA and protein and the inhibition of transcription measured using an SBP1 reporter construct. The opposing effects of SBP1 and GPX1 on each other were also observed when GPX1 was increased by supplementing the media of these tissue culture cells with selenium, and the effect of selenium on SBP1 was shown to be GPX1 dependent. Decreasing or increasing GPX1 levels in colonic epithelial cells of mice fed a selenium-deficient, -adequate or -supplemented diet resulted in the opposing effect on SBP1 levels. These data are explained in part by the demonstration that SBP1 and GPX1 form a physical association, as determined by coimmunoprecipitation and fluorescence resonance energy transfer assay. The results presented establish an interaction between two distinct selenium-containing proteins that may enhance the understanding of the mechanisms by which selenium and selenoproteins affect carcinogenesis in humans.

Effect of selenium nanoparticles with different sizes in primary cultured intestinal epithelial cells of crucian carp, Carassius auratus gibelio

“…Numerous experimental studies had suggested that the intestinal epithelial cell as a model of intestinal metabolism had been successfully used for trace elements. [27][28][29][30] In the present study, the primary cultured intestinal epithelial cells of the crucian carp, Carassius auratus gibelio, were used to evaluate the effect of nano-Se with different sizes and concentrations on related enzyme activities and protein contents.…”

Proteomic responses of blue mussel (Mytilus) congeners to temperature acclimation

“…Examples in M. galloprovincialis include thioredoxin peroxidase (also known as peroxiredoxin), which detoxifies hydrogen peroxide or organic peroxides (Cox et al, 2010), and carbonyl reductase, which metabolizes lipid peroxidation products like carbonyl-containing aldehydes (Ellis, 2007). The function of selenium binding protein-1 is not known, but it may interact with glutathione peroxidase and thus affect the scavenging of ROS indirectly (Fang et al, 2010). In M. trossulus, DyP-type peroxidase catalyzes the conversion of H 2 O 2 into H 2 O (Sugano, 2009).…”

Transforming growth factor-β1 induces glutathione peroxidase-1 and protects from H2O2-induced cell death in colon cancer cells via the Smad2/ERK1/2/HIF-1α pathway

“…Sample values obtained with specific primer sets were normalized to β-actin primer set values. For qRT-PCR, the following primer were used: β-actin, forward, 5'-GTCCACCGCAAATGCTTCTA-3' and reverse, 5'-TGCTGTCACCTTCACCGTTC-3'; GPx-1, forward, 5'-CC AAGCTCATCACCTGGTCT-3' and reverse primer, 5'-TCGAT GTCAATGGTCTGGAA-3' as recently described by us (20).…”