Analysis of the Interactions Between Thioredoxin and 20 Selenoproteins in Chicken

Thioredoxin (Trx) is a small molecular protein with complicated functions in a number of processes, including inflammation, apoptosis, embryogenesis, cardiovascular disease, and redox regulation. Some selenoproteins, such as glutathione peroxidase (Gpx), iodothyronine deiodinase (Dio), and thioredoxin reductase (TR), are involved in redox regulation. However, whether there are interactions between Trx and selenoproteins is still not known. In the present paper, we used a Modeller, Hex 8.0.0, and the KFC2 Server to predict the interactions between Trx and selenoproteins. We used the Modeller to predict the target protein in objective format and assess the accuracy of the results. Molecular interaction studies with Trx and selenoproteins were performed using the molecular docking tools in Hex 8.0.0. Next, we used the KFC2 Server to further test the protein binding sites. In addition to the selenoprotein physiological functions, we also explored potential relationships between Trx and selenoproteins beyond all the results we got. The results demonstrate that Trx has the potential to interact with 19 selenoproteins, including iodothyronine deiodinase 1 (Dio1), iodothyronine deiodinase 3 (Dio3), glutathione peroxidase 1 (Gpx1), glutathione peroxidase 2 (Gpx2), glutathione peroxidase 3 (Gpx3), glutathione peroxidase 4 (Gpx4), selenoprotein H (SelH), selenoprotein I (SelI), selenoprotein M (SelM), selenoprotein N (SelN), selenoprotein T (SelT), selenoprotein U (SelU), selenoprotein W (SelW), selenoprotein 15 (Sep15), methionine sulfoxide reductase B (Sepx1), selenophosphate synthetase 1 (SPS1), TR1, TR2, and TR3, among which TR1, TR2, TR3, SPS1, Sep15, SelN, SelM, SelI, Gpx2, Gpx3, Gpx4, and Dio3 exhibited intense correlations with Trx. However, additional experiments are needed to verify them.     

Decreased Expression of Selenoproteins as a Poor Prognosticator of Gastric Cancer in Humans

The aim of the present study was to analyze the selenoprotein expression levels in gastric cancer patients. We enrolled 40 patients (29 males, 11 females) who were recently diagnosed with gastric cancer and 50 healthy people (30 males, 20 females) as controls. The expression of 25 selenoprotein genes (Dio1, Dio2, Dio3, Gpx1, Gpx2, Gpx3, Gpx4, Gpx6, SelH, SelI, SelK, SelM, SelN, SelO, SelP, SelS, SelT, SelV, SelW, SelX, Sel15, Sps2, TR1, TR2, and TR3) in human gastric cancer tissues, para-carcinoma tissues, adjacent normal gastric tissues, erythrocytes, and lymphocytes in the gastric cancer group and healthy control group was analyzed by qRT-PCR. Here, we showed that among the 25 selenoproteins, 13 selenoproteins in erythrocytes (Gpx1, Gpx4, Sel15, TR1, TR2, SelH, SelK, SelM, SelO, SelS, SelV, SelW, and Sps2), 15 selenoproteins in lymphocytes (Gpx1, Gpx4, Sel15, TR1, TR2, SelH, SelK, SelN, SelO, SelS, SelT, SelV, SelX, SelW, and Sps2) and 13 selenoproteins in gastric cancer and para-carcinoma tissues (Dio1, Dio2, Dio3, Gpx1, Gpx4, Sel15, SelH, SelK, SelM, SelS, SelT, SelW, and Sps2) were significantly decreased (P < 0.05) in the gastric cancer group compared to the control group. In summary, the decreasing expression of selenoprotein genes in gastric cancer patients play an important role in the gastric cancer, although further studies are needed to better understand our findings.     

Effect of Selenium on Selenoprotein Expression in the Adipose Tissue of Chickens

This study describes the effects of selenium (Se) deficiency on the messenger ribonucleic acid (mRNA) expression of 25 selenoproteins (Sels) (including glutathione peroxidases (GPx1–GPx4), thioredoxin reductases (TrxR1–TrxR3), iodothyronine deiodinases (ID1–ID3), selenophosphate synthetase 2 (SPS2), 15-kDa Sel (Sel15), SelH, SelI, SelK, SelM, Sepn1, SelO, Sepx, Selpb, SelS, SelT, SelW, Sepp1, and SelU in the adipose tissues (subcutaneous adipose, visceral adipose, and articular adipose) of chickens. One hundred and fifty 1-day-old chickens were randomly assigned to two groups of 75 each and were fed a low-Se diet (0.032 mg/kg Se) or a control diet (0.282 mg/kg Se). The expression levels of 25 Sel mRNAs were determined on days 35, 45, and 55 from three parts (subcutaneous adipose, visceral adipose, and articular adipose) of the chicken adipose tissues. The results showed that the expression levels of the 25 Sel mRNAs were significantly lower (P?<?0.05) in the low-selenium group than in the control group. In addition, the Sel mRNA expression levels in the three adipose tissues were observed to decrease in a time-dependent manner with increasing feeding time.     

人与大猩猩,黑猩猩和猩猩亲缘关系的探讨

有关人锆超科的系统发育仍然存在刍议。争论焦点在与大猩猩和黑猩猩哪 个关系更近一点。酪氨酸酶是黑色素合成中的关键酶,酪氨酶基因的突变将导致白化病。测定了人猿科中大猩猩,黑猩猩、猩猩和长臂锆产基因全部５个外显子的ＤＮＡ序列。     

Identification of the human mitochondrial oxodicarboxylate carrier. Bacterial expression, reconstitution, functional characterization, tissue distribution, and chromosomal location

In Saccharomyces cerevisiae, the genes ODC1 and ODC2 encode isoforms of the oxodicarboxylate carrier. They both transport C5-C7 oxodicarboxylates across the inner membranes of mitochondria and are members of the family of mitochondrial carrier proteins. Orthologs are encoded in the genomes of Caenorhabditis elegans and Drosophila melanogaster, and a human expressed sequence tag (EST) encodes part of a closely related protein. Information from the EST has been used to complete the human cDNA sequence. This sequence has been used to map the gene to chromosome 14q11.2 and to show that the gene is expressed in all tissues that were examined. The human protein was produced by overexpression in Escherichia coli, purified, and reconstituted into phospholipid vesicles. It has similar transport characteristics to the yeast oxodicarboxylate carrier proteins (ODCs). Both the human and yeast ODCs catalyzed the transport of the oxodicarboxylates 2-oxoadipate and 2-oxoglutarate by a counter-exchange mechanism. Adipate, glutarate, and to a lesser extent, pimelate, 2-oxopimelate, 2-aminoadipate, oxaloacetate, and citrate were also transported by the human ODC. The main differences between the human and yeast ODCs are that 2-aminoadipate is transported by the former but not by the latter, whereas malate is transported by the yeast ODCs but not by the human ortholog. In mammals, 2-oxoadipate is a common intermediate in the catabolism of lysine, tryptophan, and hydroxylysine. It is transported from the cytoplasm into mitochondria where it is converted into acetyl-CoA. Defects in human ODC are likely to be a cause of 2-oxoadipate acidemia, an inborn error of metabolism of lysine, tryptophan, and hydroxylysine.     

Oxidative stress, human genetic variation, and disease

Oxidative stress has been implicated in numerous pathophysiological conditions and also aging. The tools for studying oxidative stress are now expanding as a result of the human genome effort and, in particular, expanding knowledge on human genetic variation. A few genetic variants, mostly in the form of single nucleotide polymorphisms of relevance to oxidative stress are already studied by a molecular epidemiologic approach. A review of the current knowledge on variant human genes that are directly implicated in human protection against oxidative stress is presented.     

Expression, purification, and characterization of stable, recombinant human adenylosuccinate lyase

The full length human adenylosuccinate lyase gene was generated by a PCR method using a plasmid encoding a truncated human enzyme as template, and was cloned into a pET-14b vector. Human adenylosuccinate lyase was overexpressed in Escherichia coli Rosetta 2(DE3)pLysS as an N-terminal histidine-tagged protein and was purified to homogeneity by a nickel-nitriloacetic acid column at room temperature. The histidine tag was removed from the human enzyme by thrombin digestion and the adenylosuccinate lyase was purified by Sephadex G-100 gel filtration. The histidine-tagged and non-tagged adenylosuccinate lyases exhibit similar values of Vmax and Km for S-AMP. Analytical ultracentrifugation and circular dichroism revealed, respectively, that the histidine-tagged enzyme is in tetrameric form with a molecular weight of 220 kDa and contains predominantly alpha-helical structure. This is the first purification procedure to yield a stable form of human adenylosuccinate lyase. The enzyme is stable for at least 5 days at 25 degrees C, and upon rapid freezing and thawing. Temperature as well as reducing agent (DTT) play critical roles in determining the stability of the human adenylosuccinate lyase.     

Human Non-persons, Feticide, and the Erosion of Dignity

Feticide, the practice of terminating the life of an otherwise viable fetus in utero, has become an increasingly common practice in obstetric centres around the globe, a concomitant of antenatal screening technologies. This paper examines this expanding practice in light of the concept of human dignity. Although it is assumed from the outset that even viable human fetuses are not persons and as such do not enjoy full membership in the moral community, it is argued that the fact that these are nevertheless human fetuses affords them prima facie moral status. Thus even those who accept a liberal position with regard to therapeutic abortion, should be concerned about these more recent developments. Indeed, how we treat viable human fetuses has implications for our prospective treatment of other human non-persons and could undermine the common human dignity we all share.     

Sequencing, cloning, and expression of human red cell-type acid phosphatase, a cytoplasmic phosphotyrosyl protein phosphatase.

Low molecular weight phosphotyrosyl protein phosphatases of human placenta and human red cell were purified and sequenced by a combination of Edman degradation and tandem mass spectrometry. Screening of a human placental lambda gt11 cDNA library yielded overlapping cDNA clones coding for two distinct human cytoplasmic low molecular weight phosphotyrosyl protein phosphatases (HCPTPs). The two longest clones, designated HCPTP1-1 and HCPTP2-1, were found to have identical nucleotide sequences, with the exception of a 108-base pair segment in the middle of the open reading frame. Polymerase chain reaction studies with human genomic DNA suggest that the difference between HCPTP1-1 and HCPTP2-1 does not result from alternative RNA splicing. Studies with a human chromosome 2-specific library confirmed that these sequences are located on chromosome 2, which is known to be the location of red cell acid phosphatase locus ACP1. The coding sequences of HCPTP1-1 and HCPTP2-1 were placed downstream from a bacteriophage T7 promoter and the proteins were expressed in Escherichia coli. The resulting recombinant enzymes (designated HCPTP-A and HCPTP-B, respectively) showed molecular weights of 18,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and both of them exhibited immunoreactivity with antisera raised against authentic human placental and bovine heart enzymes. The expressed proteins were highly active towards the phosphatase substrates p-nitrophenyl phosphate, beta-naphthyl phosphate, and O-phospho-L-tyrosine, but not alpha-naphthyl phosphate, threonine phosphate, or O-phospho-L-serine. HCPTP-A and -B possessed effectively identical amino acid compositions, immunoreactivities, inhibition by formaldehyde, and kinetic properties when compared with two human red cell acid phosphatase isoenzymes. It is concluded that HCPTP-A and -B are the fast and slow forms of red cell acid phosphatase, respectively, and that this enzyme is not unique to the red cell but is instead expressed in all human tissues.     

On human speech,syntax, and language

The evolution of human speech and syntax, which appear to be the defining characteristics of modern human beings, is discussed. Speech depends on the morphology of the mouth, tongue, and larynx which yield the human «vocal tract», and neural mechanisms that facilitate the perception of speech and make possible the control of the articulatory gestures that underly speech. The neural mechanisms that underly human syntax may have derived by means of the Darwinian process of preadaption from the structures of the brain that first evolved to facilitate speech motor control. Recent data consistent with this theory are presented; deficits in the comprehension of syntax of normal aged people are correlated with a slowdown in speech rate.     

Chimera,spandrel, or adaptation

In every known human society, some kind—usually many kinds—of art is practiced, frequently with much vigor and pleasure, so that one could at least hypothesize that “artifying” or “artification” is a characteristic behavior of our species. Yet human ethologists and sociobiologists have been conspicuously unforthcoming about this observably widespread and valued practice, for a number of stated and unstated reasons. The present essay is a position paper that offers an overview and analysis of conceptual issues and problems inherent in viewing art and/or aesthetics as adaptive, and it presents a speculative account of a human behavior of art. Ellen Dissanayake is an independent scholar who has straddled the abyss between biology and art for more than twenty years. She is currently a Visiting Fellow at the Institute for Advanced Studies in the Humanities, University of Edinburgh.     

Comparison of the mutations induced by p-benzoquinone, a benzene metabolite, in human and mouse cells

Benzene is one of the chemicals widely contaminating the environment. Benzene is suggested to be a human leukemogen. When benzene is absorbed in the human body, it is metabolized firstly in the liver and subsequently in the bone marrow where it provokes initiation of leukemia. In the present study, we analyzed mutations induced by p-benzoquinone (p-BQ), a benzene metabolite, in human cells using a shuttle vector plasmid pMY189, and compared frequencies, types and spectra of the mutations with those of the mutations previously revealed in mouse cells using a similar plasmid pNY200. We found that p-BQ induces mutations in human and mouse cells at similar frequencies but with different types of mutagenesis. The proportion of tandem base mutations was significantly lower in human cells than in mouse cells. Most base substitutions were induced in G:C base pairs in both human and mouse cells. However, the proportion of G:C-->C :G transversion is significantly higher in human cells. These findings indicate that the p-BQ-induced DNA damage in human and mouse cells is processed in a different manner, and that extrapolation of mice findings on experimental benzene carcinogenesis to human cancer risk assessment should be conducted carefully.     

The human T-type amino acid transporter-1: characterization, gene organization, and chromosomal location

System T is a Na+-independent transport system that selectively transports aromatic amino acids. Here, we determined the structure of the human T-type amino-acid transporter-1 (TAT1) cDNA and gene (SLC16A10). The human TAT1 cDNA encoded a 515-amino-acid protein with 12 putative membrane-spanning domains. Human SLC16A10 was localized on human chromosome 6, mapped to 6q21-q22. SLC16A10 contains six exons spanning 136 kb. In contrast to rat TAT1, which is mainly present in the intestine, human TAT1 was strongly expressed in human kidney as well as in human intestine. Expression of human TAT1 in Xenopus laevis oocytes demonstrated the Na+-independent transport of tryptophan, tyrosine, phenylalanine, and L-dopa, indicating that human TAT1 is a transporter subserving system T. Because human TAT1 is proposed to be crucial to the efficient absorption of aromatic amino acids from intestine and kidney, its defect could be involved in the disruption of aromatic amino-acid transport, such as in blue diaper syndrome.     

Neocentromeres: role in human disease,evolution, and centromere study

The centromere is essential for the proper segregation and inheritance of genetic information. Neocentromeres are ectopic centromeres that originate occasionally from noncentromeric regions of chromosomes. Despite the complete absence of normal centromeric alpha-satellite DNA, human neocentromeres are able to form a primary constriction and assemble a functional kinetochore. Since the discovery and characterization of the first case of a human neocentromere in our laboratory a decade ago, 60 examples of constitutional human neocentromeres distributed widely across the genome have been described. Typically, these are located on marker chromosomes that have been detected in children with developmental delay or congenital abnormalities. Neocentromeres have also been detected in at least two types of human cancer and have been experimentally induced in Drosophila. Current evidence from human and fly studies indicates that neocentromere activity is acquired epigenetically rather than by any alteration to the DNA sequence. Since human neocentromere formation is generally detrimental to the individual, its biological value must lie beyond the individual level, such as in karyotype evolution and speciation.     

The cloning, genomic structure, localization, and expression of human deoxyribonuclease IIbeta

Acidic endonuclease activity is present in all cells in the body and much of this can be attributed to the previously cloned and ubiquitously expressed deoxyribonuclease II (DNase II). Database analysis revealed the existence of expressed sequence tags and genomic segments coding for a protein with considerable homology to DNase II. This report describes the cloning of this cDNA, which we term deoxyribonuclease IIbeta (DNase IIbeta) and comparison of its expression to that of the originally cloned DNase II (now termed DNase IIalpha). The cDNA encodes a 357 amino acid protein. This protein exhibits extensive homology to DNase IIalpha including an amino-terminal signal peptide and a conserved active site, and has many of the regions of identity that are conserved in homologs in other mammals as well as C. elegans and Drosophila. The gene encoding DNase IIbeta has identical splice sites to DNase IIalpha. Human DNase IIbeta is highly expressed in the salivary gland, and at low levels in trachea, lung, prostate, lymph node, and testis, whereas DNase IIalpha is ubiquitously expressed in all tissues. The expression pattern of human DNase IIbeta suggests that it may function primarily as a secreted enzyme. Human saliva was found to contain DNase IIalpha, but after immunodepletion, considerable acid-active endonuclease remained which we presume is DNase IIbeta. We have localized the gene for human DNase IIbeta to chromosome 1p22.3 adjacent (and in opposing orientation) to the human uricase pseudogene. Interestingly, murine DNase IIbeta is highly expressed in the liver. Uricase is also highly expressed in mouse but not human liver and this may explain the difference in expression patterns between human and mouse DNase IIbeta.