Articles de revues : « NRD convertase »

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HOSPITAL, Véronique, Valérie CHESNEAU, Agnès BALOGH, Catherine JOULIE, Nabil G. SEIDAH, Paul COHEN et Annik PRAT. « N-arginine dibasic convertase (nardilysin) isoforms are soluble dibasic-specific metalloendopeptidases that localize in the cytoplasm and at the cell surface ». Biochemical Journal 349, n^o 2 (10 juillet 2000) : 587–97. http://dx.doi.org/10.1042/bj3490587.

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N-arginine (R) dibasic (NRD) convertase (nardilysin; EC 3.4.24.61), a metalloendopeptidase of the M16 family, specifically cleaves peptide substrates at the N-terminus of arginines in dibasic motifs in vitro. In rat testis, the enzyme localizes within the cytoplasm of spermatids and associates with microtubules of the manchette and axoneme. NRD1 and NRD2 convertases, two NRD convertase isoforms, differ by the absence (isoform 1) or presence (isoform 2) of a 68-amino acid insertion close to the active site. In this study, we overexpressed both isoforms, either by vaccinia virus infection of BSC40 cells or transfection of COS-7 cells. The partially purified enzymes exhibit very similar biochemical and enzymic properties. Microsequencing revealed that NRD convertase is N-terminally processed. Results of immunocytofluorescence, immunoelectron microscopy and subcellular fractionation studies argue in favour of a primary cytosolic localization of both peptidases. Although the putative signal peptide did not direct NRD convertase into microsomes in an in vitro translation assay, biotinylation experiments clearly showed the presence of both isoforms at the cell surface. In conclusion, although most known processing events at pairs of basic residues are achieved by proprotein convertases within the secretory pathway, NRD convertase may fulfil a similar function in the cytoplasm and/or at the cell surface.

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HOSPITAL, Véronique, Annik PRAT, Catherine JOULIE, Dorra CHÉRIF, Robert DAY et Paul COHEN. « Human and rat testis express two mRNA species encoding variants of NRD convertase, a metalloendopeptidase of the insulinase family ». Biochemical Journal 327, n^o 3 (1 novembre 1997) : 773–79. http://dx.doi.org/10.1042/bj3270773.

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Rat testis NRD convertase (EC 3.4.24.61) is a Zn2+-dependent endopeptidase that cleaves, in vitro, peptide substrates at the N-terminus of Arg residues in dibasic sites. This putative processing enzyme of the insulinase family of metallopeptidases exhibits a significant degree of similarity to insulinase and two yeast processing enzymes, Axl1 and Ste23. We report the cloning of two human testis cDNA species encoding isoforms of NRD convertase, hNRD1 and hNRD2. Whereas the hNRD1 transcript (3.7 kb) is equivalent to the previously characterized rat cDNA (rNRD1), hNRD2 and rNRD2 are 3.9 kb novel forms containing a nucleotide insertion encoding a 68-residue segment. This motif, which is inserted N-terminal of the Zn2+-binding site, HXXEH, is contained within the most conserved region among the insulinase family members. Analysis of the deduced primary sequences revealed 92% identity between rat and human orthologues. The human gene encoding NRD convertase was localized to chromosome 1p32.1-p32.2. Whereas NRD convertase is mostly expressed in testis and in 24 cell lines, low mRNA levels were detected in most of the 27 other tissues tested.

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Chesneau, V., A. Prat, D. Segretain, V. Hospital, A. Dupaix, T. Foulon, B. Jegou et P. Cohen. « NRD convertase : a putative processing endoprotease associated with the axoneme and the manchette in late spermatids ». Journal of Cell Science 109, n^o 11 (1 novembre 1996) : 2737–45. http://dx.doi.org/10.1242/jcs.109.11.2737.

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N-arginine dibasic convertase is a novel metalloendopeptidase which selectively cleaves at the N terminus of arginine residues in paired basic amino acids. Although present in brain and several other tissues, NRD convertase is particularly abundant in testis, where its expression appeared to be restricted to germ cells. Low levels of both mRNA and its corresponding protein were detected early in spermatogenesis. However, a marked accumulation of the protein was observed during late steps (14 to 19) of spermiogenesis. By electron microscopy, the NRD convertase immunoreactivity was localized in the cytoplasm of elongating and elongated spermatids, with a noticeable concentration at the level of two microtubular structures, i.e. the manchette and the axoneme. These observations strongly support the hypothesis that NRD convertase is involved in processing events potentially associated with the morphological transformations occurring during spermiogenesis.

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Csuhai, Eva, Maria Aparecida Juliano, Luiz Juliano et Louis B. Hersh. « Kinetic Analysis of Spermine Binding to NRD Convertase ». Archives of Biochemistry and Biophysics 362, n^o 2 (février 1999) : 291–300. http://dx.doi.org/10.1006/abbi.1998.1029.

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Psatha, Maria, Andrew Winter et Adrian R. Pierotti. « Analysis of regulatory sequences in the NRD Convertase promoter ». Biochemical Society Transactions 28, n^o 3 (1 juin 2000) : A83. http://dx.doi.org/10.1042/bst028a083b.

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WINTER, Andrew G., et Adrian R. PIEROTTI. « Gene expression of the dibasic-pair cleaving enzyme NRD convertase (N-arginine dibasic convertase) is differentially regulated in the GH3 pituitary and Mat-Lu prostate cell lines ». Biochemical Journal 351, n^o 3 (24 octobre 2000) : 755–64. http://dx.doi.org/10.1042/bj3510755.

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NRD convertase (N-arginine dibasic convertase, NRD-C) is a dibasic selective metalloprotease which cleaves on the N-terminal side of an arginine residue in a dibasic pair. Abundant in endocrine tissues, the highest levels are found in testis. The mechanism whereby NRD-C expression is regulated at the transcriptional level has been examined by reporter-gene assay and electrophoretic-mobility-shift assays. Analysis of the rat and human promoters show that they are highly conserved, containing a number of motifs which may correspond to transcription-factor binding sites. The rat promoter has been cloned into a luciferase reporter vector and analysed in a number of cell lines. Full functionality of the promoter is observed with 5′ deletions to 411bp upstream of the transcriptional start site in spermatid, prostate and pituitary cell lines. Further deletion to 101bp causes a complete loss of activity in spermatid and prostate lines. By contrast, GH3 pituitary cells display no reduction in promoter activity with deletion to 101bp of upstream sequence. A number of transcription-factor binding sites have been identified by electrophoretic-mobility-shift assays in the region 411–101; however, no differences in binding between the cell lines were observed.

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Chesneau, V., A. R. Pierotti, A. Prat, F. Gaudoux, T. Foulon et P. Cohen. « N-arginine dibasic convertase (NRD convertase) : a newcomer to the family of processing endopeptidases. An overview ». Biochimie 76, n^o 3-4 (janvier 1994) : 234–40. http://dx.doi.org/10.1016/0300-9084(94)90151-1.

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Psatha, M. I., J. A. Craft et A. R. Pierotti. « Regulation of the expression of NRD-Convertase : a novel promoter element ». Biochemical Society Transactions 29, n^o 5 (1 octobre 2001) : A130. http://dx.doi.org/10.1042/bst029a130.

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Psatha, M. I., et A. R. Pierotti. « Identification of a putative cell type specific repressor activity within the NRD convertase gene promoter ». Biochemical Society Transactions 30, n^o 1 (1 février 2002) : A42. http://dx.doi.org/10.1042/bst030a042.

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Fumagalli, P., M. Accarino, A. Egeo, P. Scartezzini, G. Rappazzo, A. Pizzuti, V. Avvantaggiato et al. « Human NRD Convertase : A Highly Conserved Metalloendopeptidase Expressed at Specific Sites during Development and in Adult Tissues ». Genomics 47, n^o 2 (janvier 1998) : 238–45. http://dx.doi.org/10.1006/geno.1997.5078.

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WINTER, Andrew G., et Adrian R. PIEROTTI. « Gene expression of the dibasic-pair cleaving enzyme NRD convertase (N-arginine dibasic convertase) is differentially regulated in the GH3 pituitary and Mat-Lu prostate cell lines ». Biochemical Journal 351, n^o 3 (1 novembre 2000) : 755. http://dx.doi.org/10.1042/0264-6021:3510755.

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Ragab, Sherif Shaban, Subramani Swaminathan, Jaume Garcia-Amorós, Burjor Captain et Françisco M. Raymo. « Bimolecular photoactivation of NBD fluorescence ». New Journal of Chemistry 39, n^o 3 (2015) : 1570–73. http://dx.doi.org/10.1039/c4nj01983k.

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Jagodzińska, Agnieszka. « Badania nad konwersją : nowe trendy, metody, wyzwania ». Studia Judaica, n^o 2 (46) (2021) : 425–36. http://dx.doi.org/10.4467/10.4467/24500100stj.20.021.13664.

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Research on Jewish Conversion: New Trends, Methods, and Challenges This review article addresses the recent popularity of studies on Jewish conversion. In particular, it examines the volume Bastards and Believers: Jewish Converts and Conversion from the Bible to the Present edited by Theodor Dunkelgrün and PawełMaciejko (Philadelphia, 2020). The author of the article suggests looking at this volume as at a representative example of recent trends, themes, methods, and challenges present in studying Jewish conversion.

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Zerez, CR, EF Jr Roth, S. Schulman et KR Tanaka. « Increased nicotinamide adenine dinucleotide content and synthesis in Plasmodium falciparum-infected human erythrocytes ». Blood 75, n^o 8 (15 avril 1990) : 1705–10. http://dx.doi.org/10.1182/blood.v75.8.1705.1705.

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Abstract Plasmodium falciparum-infected red blood cells (RBCs) are characterized by increases in the activity of glycolytic enzymes. Because nicotinamide adenine dinucleotide (NAD) and NAD phosphate (NADP) are cofactors in the reactions of glycolysis and pentose phosphate shunt, we have examined NAD and NADP content in P. falciparum-infected RBCs. Although NADP content was not significantly altered, NAD content was increased approximately 10-fold in infected RBCs (66% parasitemia) compared with uninfected control RBCs. To determine the mechanism for the increase in NAD content, we examined the activity of several NAD biosynthetic enzymes. It is known that normal human RBCs make NAD exclusively from nicotinic acid and lack the capacity to make NAD from nicotinamide. We demonstrate that infected RBCs have readily detectable nicotinamide phosphoribosyltransferase (NPRT), the first enzyme in the NAD biosynthetic pathway that uses nicotinamide, and abundant nicotinamide deamidase, the enzyme that converts nicotinamide to nicotinic acid, thereby indicating that infected RBCs can make NAD from nicotinamide. In addition, infected RBCs have a threefold increase in nicotinic acid phosphoribosyltransferase (NAPRT), the first enzyme in the NAD biosynthetic pathway that uses nicotinic acid. Thus, the increase in NAD content in P falciparum-infected RBCs appears to be mediated by increases in NAD synthesis from both nicotinic acid and nicotinamide.

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Zerez, CR, EF Jr Roth, S. Schulman et KR Tanaka. « Increased nicotinamide adenine dinucleotide content and synthesis in Plasmodium falciparum-infected human erythrocytes ». Blood 75, n^o 8 (15 avril 1990) : 1705–10. http://dx.doi.org/10.1182/blood.v75.8.1705.bloodjournal7581705.

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Plasmodium falciparum-infected red blood cells (RBCs) are characterized by increases in the activity of glycolytic enzymes. Because nicotinamide adenine dinucleotide (NAD) and NAD phosphate (NADP) are cofactors in the reactions of glycolysis and pentose phosphate shunt, we have examined NAD and NADP content in P. falciparum-infected RBCs. Although NADP content was not significantly altered, NAD content was increased approximately 10-fold in infected RBCs (66% parasitemia) compared with uninfected control RBCs. To determine the mechanism for the increase in NAD content, we examined the activity of several NAD biosynthetic enzymes. It is known that normal human RBCs make NAD exclusively from nicotinic acid and lack the capacity to make NAD from nicotinamide. We demonstrate that infected RBCs have readily detectable nicotinamide phosphoribosyltransferase (NPRT), the first enzyme in the NAD biosynthetic pathway that uses nicotinamide, and abundant nicotinamide deamidase, the enzyme that converts nicotinamide to nicotinic acid, thereby indicating that infected RBCs can make NAD from nicotinamide. In addition, infected RBCs have a threefold increase in nicotinic acid phosphoribosyltransferase (NAPRT), the first enzyme in the NAD biosynthetic pathway that uses nicotinic acid. Thus, the increase in NAD content in P falciparum-infected RBCs appears to be mediated by increases in NAD synthesis from both nicotinic acid and nicotinamide.

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Lucas, Phillip Charles. « Enfants Terribles : The Challenge of Sectarian Converts to Ethnic Orthodox Churches in the United States ». Nova Religio 7, n^o 2 (1 novembre 2003) : 5–23. http://dx.doi.org/10.1525/nr.2003.7.2.5.

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This article considers two case studies of collective conversions to Eastern Orthodoxy to illustrate the most pressing challenges faced by ethnic Orthodox congregations who attempt to assimilate sectarian groups into their midst. I argue that these challenges include: 1) the different understandings of ecclesiology held by former Protestant sectarians and by "cradle" Orthodox believers; 2) the pan-Orthodox aspirations of sectarian converts versus the factionalism found in ethnically-based American Orthodox jurisdictions; 3) the differing pastoral styles of former sectarian ministers and Orthodox priests; 4) the tendency of sectarian converts to embrace a very strict reading of Orthodoxy and to adopt a critical and reformist attitude in relations with cradle Orthodox communities; and 5) the covert and overt racism that sometimes exists in ethnic Orthodox parishes. I suggest that the increasing numbers of non-ethnic converts to ethnic Orthodox parishes may result in increased pressure to break down ethnic barriers between Orthodox communities and to form a unified American Orthodox Church. These conversions may also lead to the growth of hybrid Orthodox churches such as the Charismatic Episcopal Church.

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Spivey, Garrett. « Turning to Tradition : Converts and the Making of an American Orthodox Church ». Nova Religio 18, n^o 3 (2014) : 138–40. http://dx.doi.org/10.1525/nr.2015.18.3.138.

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Gallo, Christopher M., Daniel L. Smith et Jeffrey S. Smith. « Nicotinamide Clearance by Pnc1 Directly Regulates Sir2-Mediated Silencing and Longevity ». Molecular and Cellular Biology 24, n^o 3 (1 février 2004) : 1301–12. http://dx.doi.org/10.1128/mcb.24.3.1301-1312.2004.

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ABSTRACT The Saccharomyces cerevisiae Sir2 protein is an NAD+-dependent histone deacetylase (HDAC) that functions in transcriptional silencing and longevity. The NAD+ salvage pathway protein, Npt1, regulates Sir2-mediated processes by maintaining a sufficiently high intracellular NAD+ concentration. However, another NAD+ salvage pathway component, Pnc1, modulates silencing independently of the NAD+ concentration. Nicotinamide (NAM) is a by-product of the Sir2 deacetylase reaction and is a natural Sir2 inhibitor. Pnc1 is a nicotinamidase that converts NAM to nicotinic acid. Here we show that recombinant Pnc1 stimulates Sir2 HDAC activity in vitro by preventing the accumulation of NAM produced by Sir2. In vivo, telomeric, rDNA, and HM silencing are differentially sensitive to inhibition by NAM. Furthermore, PNC1 overexpression suppresses the inhibitory effect of exogenously added NAM on silencing, life span, and Hst1-mediated transcriptional repression. Finally, we show that stress suppresses the inhibitory effect of NAM through the induction of PNC1 expression. Pnc1, therefore, positively regulates Sir2-mediated silencing and longevity by preventing the accumulation of intracellular NAM during times of stress.

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Harris, Ben G., G. S. Jagannatha Rao, David E. Coleman, G. Kulkarni, E. J. Goldsmith et Paul F. Cook. « NAD-Malic Enzyme from Ascaris suum : Sequence and Structural Studies ». Protein & ; Peptide Letters 7, n^o 5 (octobre 2000) : 297–304. http://dx.doi.org/10.2174/092986650705221207142546.

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Abstract: Ascaris suum malic enzyme belongs to the class of oxidative decarboxylases and converts L-malate to pyruvate utilizing NAD and a divalent metal cofactor. It plays a key role in the energy metabolism of the parasite and hence is a target for chemotherapy. It has been extensively characterized from the standpoint of its kinetic, regulatory and chemical mechanisms. Recent studies involving site specific mutants and the determination of its complete sequence as well as quaternary structure have greatly facilitated elucidation of its catalytic mechanism.

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Grose, Julianne H., Ulfar Bergthorsson et John R. Roth. « Regulation of NAD Synthesis by the Trifunctional NadR Protein of Salmonella enterica ». Journal of Bacteriology 187, n^o 8 (15 avril 2005) : 2774–82. http://dx.doi.org/10.1128/jb.187.8.2774-2782.2005.

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ABSTRACT The three activities of NadR were demonstrated in purified protein and assigned to separate domains by missense mutations. The N-terminal domain represses transcription of genes for NAD synthesis and salvage. The C-terminal domain has nicotinamide ribose kinase (NmR-K; EC 2.7.1.22) activity, which is essential for assimilation of NmR, converting it internally to nicotinamide mononucleotide (NMN). The central domain has a weak adenylyltransferase (NMN-AT; EC 2.7.7.1) activity that converts NMN directly to NAD but is physiologically irrelevant. This central domain mediates regulatory effects of NAD on all NadR activities. In the absence of effectors, pure NadR protein binds operator DNA (the default state) and is released by ATP (expected to be present in vivo). NAD allows NadR to bind DNA in the presence of ATP and causes repression in vivo. A superrepressor mutation alters an ATP-binding residue in the central (NMN-AT) domain. This eliminates NMN-AT activity and places the enzyme in its default (DNA binding) state. The mutant protein shows full NmR kinase activity that is 10-fold more sensitive to NAD inhibition than the wild type. It is proposed that NAD and the superrepressor mutation exert their effects by preventing ATP from binding to the central domain.

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Susan Wong, F., Irene Visintin, Li Wen, Jennifer Granata, Richard Flavell et Charles A. Janeway. « The Role of Lymphocyte Subsets in Accelerated Diabetes in Nonobese Diabetic–Rat Insulin Promoter–B7-1 (NOD-RIP-B7-1) Mice ». Journal of Experimental Medicine 187, n^o 12 (15 juin 1998) : 1985–93. http://dx.doi.org/10.1084/jem.187.12.1985.

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B7-1 transgene expression on the pancreatic islets in nonobese diabetic (NOD) mice leads to accelerated diabetes, with >50% of animals developing diabetes before 12 wk of age. The expression of B7-1 directly on the pancreatic β cells, which do not normally express costimulator molecules, converts the cells into effective antigen-presenting cells leading to an intensified autoimmune attack. The pancreatic islet infiltrate in diabetic mice consists of CD8 T cells, CD4 T cells, and B cells, similar to diabetic nontransgenic NOD mice. To elucidate the relative importance of each of the subsets of cells, the NOD–rat insulin promoter (RIP)-B7-1 animals were crossed with NOD.β2microglobulin −/− mice which lack major histocompatibility complex class I molecules and are deficient in peripheral CD8 T cells, NOD.CD4 −/− mice which lack T cells expressing CD4, and NOD.μMT −/− mice which lack B220-positive B cells. These experiments showed that both CD4 and CD8 T cells were necessary for the accelerated onset of diabetes, but that B cells, which are needed for diabetes to occur in normal NOD mice, are not required. It is possible that B lymphocytes play an important role in the provision of costimulation in NOD mice which is unnecessary in the NOD-RIP-B7-1 transgenic mice.

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Daniel, Carolin, Benno Weigmann, Roderick Bronson et Harald von Boehmer. « Prevention of type 1 diabetes in mice by tolerogenic vaccination with a strong agonist insulin mimetope ». Journal of Experimental Medicine 208, n^o 7 (20 juin 2011) : 1501–10. http://dx.doi.org/10.1084/jem.20110574.

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Type 1 diabetes (T1D) results from the destruction of insulin-secreting pancreatic β cells by autoreactive T cells. Insulin is an essential target of the autoimmune attack. Insulin epitopes recognized by diabetogenic T cell clones bind poorly to the class II I-Ag7 molecules of nonobese diabetic (NOD) mice, which results in weak agonistic activity of the peptide MHC complex. Here, we describe a strongly agonistic insulin mimetope that effectively converts naive T cells into Foxp3+ regulatory T cells in vivo, thereby completely preventing T1D in NOD mice. In contrast, natural insulin epitopes are ineffective. Subimmunogenic vaccination with strongly agonistic insulin mimetopes might represent a novel strategy to prevent T1D in humans at risk for the disease.

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Morita, Rimpei, Mayu Suzuki, Hidenori Kasahara, Nana Shimizu, Takashi Shichita, Takashi Sekiya, Akihiro Kimura, Ken-ichiro Sasaki, Hideo Yasukawa et Akihiko Yoshimura. « ETS transcription factor ETV2 directly converts human fibroblasts into functional endothelial cells ». Proceedings of the National Academy of Sciences 112, n^o 1 (24 décembre 2014) : 160–65. http://dx.doi.org/10.1073/pnas.1413234112.

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Transplantation of endothelial cells (ECs) is a promising therapeutic approach for ischemic disorders. In addition, the generation of ECs has become increasingly important for providing vascular plexus to regenerated organs, such as the liver. Although many attempts have been made to generate ECs from pluripotent stem cells and nonvascular cells, the minimum number of transcription factors that specialize in directly inducing vascular ECs remains undefined. Here, by screening 18 transcription factors that are important for both endothelial and hematopoietic development, we demonstrate that ets variant 2 (ETV2) alone directly converts primary human adult skin fibroblasts into functional vascular endothelial cells (ETVECs). In coordination with endogenous FOXC2 in fibroblasts, transduced ETV2 elicits expression of multiple key endothelial development factors, including FLI1, ERG, and TAL1, and induces expression of endothelial functional molecules, including EGFL7 and von Willebrand factor. Consequently, ETVECs exhibits EC characteristics in vitro and forms mature functional vasculature in Matrigel plugs transplanted in NOD SCID mice. Furthermore, ETVECs significantly improve blood flow recovery in a hind limb ischemic model using BALB/c-nu mice. Our study indicates that the creation of ETVECs provides further understanding of human EC development induced by ETV2.

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Liu, Hui-wen, Chadwick B. Smith, Mark S. Schmidt, Xiaolu A. Cambronne, Michael S. Cohen, Marie E. Migaud, Charles Brenner et Richard H. Goodman. « Pharmacological bypass of NAD+ salvage pathway protects neurons from chemotherapy-induced degeneration ». Proceedings of the National Academy of Sciences 115, n^o 42 (26 septembre 2018) : 10654–59. http://dx.doi.org/10.1073/pnas.1809392115.

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Axon degeneration, a hallmark of chemotherapy-induced peripheral neuropathy (CIPN), is thought to be caused by a loss of the essential metabolite nicotinamide adenine dinucleotide (NAD+) via the prodegenerative protein SARM1. Some studies challenge this notion, however, and suggest that an aberrant increase in a direct precursor of NAD+, nicotinamide mononucleotide (NMN), rather than loss of NAD+, is responsible. In support of this idea, blocking NMN accumulation in neurons by expressing a bacterial NMN deamidase protected axons from degeneration. We hypothesized that protection could similarly be achieved by reducing NMN production pharmacologically. To achieve this, we took advantage of an alternative pathway for NAD+ generation that goes through the intermediate nicotinic acid mononucleotide (NAMN), rather than NMN. We discovered that nicotinic acid riboside (NAR), a precursor of NAMN, administered in combination with FK866, an inhibitor of the enzyme nicotinamide phosphoribosyltransferase that produces NMN, protected dorsal root ganglion (DRG) axons against vincristine-induced degeneration as well as NMN deamidase. Introducing a different bacterial enzyme that converts NAMN to NMN reversed this protection. Collectively, our data indicate that maintaining NAD+ is not sufficient to protect DRG neurons from vincristine-induced axon degeneration, and elevating NMN, by itself, is not sufficient to cause degeneration. Nonetheless, the combination of FK866 and NAR, which bypasses NMN formation, may provide a therapeutic strategy for neuroprotection.

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Kościańska, Agnieszka. « „Potęga ciszy” — z antropologicznych studiów nad genderowym wymiarem alternatywnej duchowości ». Kultura i Społeczeństwo 52, n^o 3 (9 juillet 2008) : 91–108. http://dx.doi.org/10.35757/kis.2008.52.3.6.

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The paper is based on ethnographic ﬁeldwork among converts from Catholicism to a marginal Hindu-rooted, female dominated new religious movement in Poland, the Brahma Kumaris, and explores the role of silence in the religious practices and everyday lives of its members. It argues that silence is a performative act in reconstruction of the informants’ gender identity and is perceived by them as form of self-valuation. From the perspective of the feminist discourse, particularly Western liberal feminism, as well as within cultural anthropology silence is often interpreted as a lack of power and opposition to speech. But drawing on the respondents’ experiences, silence can also be understood as and expression of strength and a means of resistance. The author presents the ways how middle class, urban women have resort to silence in he aim to deal better with the problems of everyday life as well as with those of economic and cultural transition, Western-style feminism, and Polish Catholicism.

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Stetsenko, Artem, Rajkumar Singh, Michael Jaehme, Albert Guskov et Dirk Jan Slotboom. « Structural and Functional Characterization of NadR from Lactococcus lactis ». Molecules 25, n^o 8 (22 avril 2020) : 1940. http://dx.doi.org/10.3390/molecules25081940.

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NadR is a bifunctional enzyme that converts nicotinamide riboside (NR) into nicotinamide mononucleotide (NMN), which is then converted into nicotinamide adenine dinucleotide (NAD). Although a crystal structure of the enzyme from the Gram-negative bacterium Haemophilus influenzae is known, structural understanding of its catalytic mechanism remains unclear. Here, we purified the NadR enzyme from Lactococcus lactis and established an assay to determine the combined activity of this bifunctional enzyme. The conversion of NR into NAD showed hyperbolic dependence on the NR concentration, but sigmoidal dependence on the ATP concentration. The apparent cooperativity for ATP may be explained because both reactions catalyzed by the bifunctional enzyme (phosphorylation of NR and adenylation of NMN) require ATP. The conversion of NMN into NAD followed simple Michaelis-Menten kinetics for NMN, but again with the sigmoidal dependence on the ATP concentration. In this case, the apparent cooperativity is unexpected since only a single ATP is used in the NMN adenylyltransferase catalyzed reaction. To determine the possible structural determinants of such cooperativity, we solved the crystal structure of NadR from L. lactis (NadRLl). Co-crystallization with NAD, NR, NMN, ATP, and AMP-PNP revealed a ‘sink’ for adenine nucleotides in a location between two domains. This sink could be a regulatory site, or it may facilitate the channeling of substrates between the two domains.

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Yamaki, Shohei, et Kazuko Ishikawa. « Roles of Four Sorbitol Related Enzymes and Invertase in the Seasonal Alteration of Sugar Metabolism in Apple Tissue ». Journal of the American Society for Horticultural Science 111, n^o 1 (janvier 1986) : 134–37. http://dx.doi.org/10.21273/jashs.111.1.134.

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Abstract Activities and roles of 4 sorbitol enzymes, sorbitol-6-P dehydrogenase, NAD+-dependent sorbitol dehydrogenase, NADP+-dependent sorbitol dehydrogenase and sorbitol oxidase, and acid invertase in apple (Malus domestica Borkh. ‘Jonnagold’) leaves and fruit were studied. Almost all of the soluble carbohydrates in leaves are present as sorbitol throughout the season. Sorbitol-6-P dehydrogenase had the highest activity among the enzymes, being high in young leaves and decreasing with age; whereas NAD+- and NADP+-dependent sorbitol dehydrogenases and sorbitol oxidase activities were barely detectable. Sorbitol was translocated from leaves to fruits where it was readily metabolized to other sugars, so the sorbitol concentration did not increase. NAD+-dependent sorbitol dehydrogenase that converts sorbitol to fructose had the highest activity of the 4 enzymes in developing fruits. Its activity rose in June, decreased in midseason, and increased again with fruit maturation. The fluctuation in enzyme activity corresponded to changes in fructose concentration. Sorbitol oxidase activity, which was about one-fifth that of NAD+-dependent sorbitol dehydrogenase, increased proportionately as fruits enlarged. Acid invertase activity was distinctly higher than sorbitol enzyme activities in both leaves and fruit, but its roles in sugar translocation and metabolism were not clearly established. The levels of sorbitol in stems and peduncles remained relatively constant during the season indicating that little metabolism occurred in the phloem during transit.

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CAKIR-KIEFER, Céline, Hélène MULLER-STEFFNER, Norman OPPENHEIMER et Francis SCHUBER. « Kinetic competence of the cADP-ribose–CD38 complex as an intermediate in the CD38/NAD+ glycohydrolase-catalysed reactions : implication for CD38 signalling ». Biochemical Journal 358, n^o 2 (24 août 2001) : 399–406. http://dx.doi.org/10.1042/bj3580399.

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CD38/NAD+ glycohydrolase is a type II transmembrane glycoprotein widely used to study T- and B-cell activation and differentiation. CD38 is endowed with two different activities: it is a signal transduction molecule and an ectoenzyme that converts NAD+ into ADP-ribose (NAD+ glycohydrolase activity) and small proportions of cADP-ribose (cADPR; ADP-ribosyl cyclase activity), a calcium-mobilizing metabolite, which, ultimately, can also be hydrolysed (cADPR hydrolase activity). The relationship between these two properties, and strikingly the requirement for signalling in the formation of free or enzyme-complexed cADPR, is still ill-defined. In the present study we wanted to test whether the CD38–cADPR complex is kinetically competent in the conversion of NAD+ into the reaction product ADP-ribose. In principle, such a complex could be invoked for cross-talk, via conformational changes, with neighbouring partner(s) of CD38 thus triggering the signalling phenomena. Analysis of the kinetic parameters measured for the CD38/NAD+ glycohydrolase-catalysed hydrolysis of 2′-deoxy-2′-aminoribo-NAD+ and ADP-cyclo[N1,C1′]-2′-deoxy-2′-aminoribose (slowly hydrolysable analogues of NAD+ and cADPR respectively) ruled out that the CD38–cADPR complex can accumulate under steady-state conditions. This was borne out by simulation of the prevalent kinetic mechanism of CD38, which involve the partitioning of a common E·ADP-ribosyl intermediate in the formation of the enzyme-catalysed reaction products. Using this mechanism, microscopic rate conditions were found which transform a NAD+ glycohydrolase into an ADP-ribosyl cyclase. Altogether, the present work shows that if the cross-talk with a partner depends on a conformational change of CD38, this is most probably not attributable to the formation of the CD38–cADPR complex. In line with recent results on the conformational change triggered by CD38 ligands [Berthelier, Laboureau, Boulla, Schuber and Deterre (2000) Eur. J. Biochem. 267, 3056–3064], we believe that the Michaelis CD38–NAD+ complex could play such a role instead.

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Bai, Xue, Jing Lan, Shanru He, Tingting Bu, Jie Zhang, Lulu Wang, Xiaoling Jin et al. « Structural and Biochemical Analyses of the Butanol Dehydrogenase from Fusobacterium nucleatum ». International Journal of Molecular Sciences 24, n^o 3 (3 février 2023) : 2994. http://dx.doi.org/10.3390/ijms24032994.

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Butanol dehydrogenase (BDH) plays a significant role in the biosynthesis of butanol in bacteria by catalyzing butanal conversion to butanol at the expense of the NAD(P)H cofactor. BDH is an attractive enzyme for industrial application in butanol production; however, its molecular function remains largely uncharacterized. In this study, we found that Fusobacterium nucleatum YqdH (FnYqdH) converts aldehyde into alcohol by utilizing NAD(P)H, with broad substrate specificity toward aldehydes but not alcohols. An in vitro metal ion substitution experiment showed that FnYqdH has higher enzyme activity in the presence of Co2+. Crystal structures of FnYqdH, in its apo and complexed forms (with NAD and Co2+), were determined at 1.98 and 2.72 Å resolution, respectively. The crystal structure of apo- and cofactor-binding states of FnYqdH showed an open conformation between the nucleotide binding and catalytic domain. Key residues involved in the catalytic and cofactor-binding sites of FnYqdH were identified by mutagenesis and microscale thermophoresis assays. The structural conformation and preferred optimal metal ion of FnYqdH differed from that of TmBDH (homolog protein of FnYqdH). Overall, we proposed an alternative model for putative proton relay in FnYqdH, thereby providing better insight into the molecular function of BDH.

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Subedi, Amit, Qiang Liu, David Sharon, Changjiang Xu, Veronique Voisin, Gary D. Bader, Jean Wang et Steven M. Chan. « Inhibition of Nicotinamide Phosphoribosyltransferase (NAMPT) Activity Selectively Targets Human Acute Myeloid Leukemia Stem Cells ». Blood 132, Supplement 1 (29 novembre 2018) : 3932. http://dx.doi.org/10.1182/blood-2018-99-120258.

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Abstract Acute myeloid leukemia (AML) is an aggressive malignancy of the bone marrow associated with poor clinical outcomes. Conventional chemotherapies are effective in debulking the leukemic burden in most AML patients. However, a small population of disease-sustaining leukemic stem cells (LSCs) frequently persists and contributes to relapsed disease. Novel therapies that eradicate LSCs have the potential to improve clinical outcomes in AML. To discover novel anti-LSC agents, we performed a high-throughput flow cytometry-based drug screen of 1,220 compounds against a primary AML sample (8227). This sample harbors distinct subsets defined by CD34 and CD38 expression, and LSC activity assayed by xenotransplantation is restricted to the CD34+CD38- fraction. Through this screen, we identified compounds that selectively depleted the CD34+CD38- fraction including four structurally-unrelated NAMPT inhibitors (FK866, STF-118804, GMX1778, and KPT-9274). These inhibitors also depleted the LSC-enriched CD34+CD38- fraction in two other primary AML samples, indicating that the effect was not unique to 8227 cells. To further evaluate their impact on LSCs in 8227, we measured the expression of 104 genes that were previously found to be differentially expressed between LSC+ and LSC- cell fractions isolated from patient samples. Treatment with NAMPT inhibitors reduced the correlation between the measured LSC gene signature and the LSC+ reference profile, providing additional evidence for their anti-LSC activity. To determine whether the selective loss of CD34+CD38- cells was due to cell death or differentiation, we sorted subsets of 8227 cells based on CD34 and CD38 expression and treated each fraction with FK866. NAMPT inhibition preferentially triggered apoptosis as measured by Annexin V staining in the CD34+CD38- and CD34+CD38+ fractions over the CD34- fraction. We did not observe significant changes in the expression of CD34, CD38, or other myeloid differentiation markers (CD14 and CD15) in the remaining viable cells. Our subsequent mechanistic studies focused on KPT-9274 because it is the furthest along in clinical development. NAMPT is the rate-limiting enzyme in the NAD+ salvage pathway that converts nicotinamide (NAM) to nicotinamide mononucleotide (NMN), a direct NAD+ precursor. To confirm a decrease in intracellular NAD+ with KPT-9274 treatment, we introduced expression of genetically-encoded biosensors for measuring NAD+ levels in different cellular compartments in an AML cell line. KPT-9274 treatment for 15 hours lowered the free NAD+ pool in the cytosol and mitochondria but not in nucleus. To determine whether the drop in NAD+ was necessary for the effects of KPT-9274 on LSCs, we supplemented the primary AML samples with nicotinamide riboside (NR) which can be directly converted to NMN, thereby bypassing the requirement for NAMPT activity to generate NAD+. The addition of NR completely rescued the effects of KPT-9274 on the CD34+CD38- fraction. Niacin can also generate NAD+ through an alternative pathway that depends on nicotinic acid phosphoribosyltransferase (NAPRT). However, niacin supplementation failed to rescue the effects of NAMPT inhibition which correlated with the lack of NAPRT expression in LSC-enriched CD34+CD38- cells. Next, we studied the effects of KPT-9274 on normal CD34+ hematopoietic stem and progenitor cells (HSPCs) isolated from human cord blood. Although HSPCs were sensitive to the pro-apoptotic effects of KPT-9274, their survival was fully rescued by both NR and niacin. The rescue by niacin correlated with a higher expression of NAPRT in HSPCs. As the blood concentration of niacin is ~1,000 fold higher than that of NR, KPT-9274 is predicted to have a favorable therapeutic window in vivo. To demonstrate its in vivo activity, we treated immunodeficient NOD/SCID/IL2Rγ-null (NSG) mice engrafted with a luciferase-tagged AML cell line (OCI-AML3) with KPT-9274 at a dose of 150 or 250 mg/kg/day or vehicle control for 50 consecutive days by oral administration. KPT-9274 treatment significantly lowered leukemia burden and prolonged survival in both dosing cohorts. In summary, our results indicate that NAMPT inhibition represents an effective approach to target human LSCs through reduction in intracellular NAD+ levels and induction of apoptosis. Our data provide the preclinical rationale for investigating the use of KPT-9274 in AML clinical trials. Disclosures Chan: Genentech: Research Funding; Celgene: Research Funding; AbbVie: Research Funding.

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Nuñez, Alberto, Thomas A. Foglia et George J. Piazza. « Cofactor recycling in a coupled enzyme oxidation–reduction reaction : conversion of ω‐oxo‐fatty acids into ω‐hydroxy and dicarboxylic acids ». Biotechnology and Applied Biochemistry 29, n^o 3 (juin 1999) : 207–12. http://dx.doi.org/10.1111/j.1470-8744.1999.tb00550.x.

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Aldehydes are reduced to alcohols by the enzyme alcohol dehydrogenase (ADH), whereas the enzyme aldehyde dehydrogenase (AldDH) oxidizes aldehydes to carboxylic acids. ADH and AldDH require, respectively, the reduced and oxidized forms of the cofactor NAD (NAD+/NADH). By combining both oxidation and reduction reactions into one process, it is possible to produce alcohols and carboxylic acids simultaneously from aldehydes by continuous recycling of the NAD+/NADH cofactor. However, both enzymes need to be active within the same pH region and buffer system. To test this hypothesis, the pH profile (Vmax and Vmax/Km) as well as the pKa of the prototropic groups involved in catalysis for both dehydrogenases were determined using (Z,Z)‐nona‐2,4‐dienal as a model substrate. The pH profile (Vmax and Vmax/Km) of both enzymes overlapped in the pH range of 6–8 in potassium phosphate buffer. When the coupled enzyme system was used at pH 7 with 10% NAD+ cofactor, over 90% of the starting aldehyde was converted to its corresponding acid and alcohol derivatives in a 1:1 ratio. The sequential action of the enzymes lipoxygenase and hydroperoxide lyase converts polyunsaturated fatty acids to aldehydic fatty acids. The products arising from the oxidation or reduction of the aldehydic functionality are of industrial interest. It was found that 13‐oxo‐9‐(Z),11‐(E)‐tridecadienoic acid, the product of the sequential reaction of soya bean lipoxygenase and hydroperoxide lyase from Chlorella pyrenoidosaon linoleic acid, is also a substrate in this coupled enzyme system.

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Reeves, Peta L. S., Rajeev Rudraraju, F. Susan Wong, Emma E. Hamilton-Williams et Raymond J. Steptoe. « Antigen presenting cell-targeted proinsulin expression converts insulin-specific CD8+ T-cell priming to tolerance in autoimmune-prone NOD mice ». European Journal of Immunology 47, n^o 9 (18 juillet 2017) : 1550–61. http://dx.doi.org/10.1002/eji.201747089.

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Lukacik, Petra, Brigitte Keller, Gabor Bunkoczi, Kathryn Kavanagh, Wen Hwa Lee, Jerzy Adamski et Udo Oppermann. « Structural and biochemical characterization of human orphan DHRS10 reveals a novel cytosolic enzyme with steroid dehydrogenase activity ». Biochemical Journal 402, n^o 3 (26 février 2007) : 419–27. http://dx.doi.org/10.1042/bj20061319.

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To this day, a significant proportion of the human genome remains devoid of functional characterization. In this study, we present evidence that the previously functionally uncharacterized product of the human DHRS10 gene is endowed with 17β-HSD (17β-hydroxysteroid dehydrogenase) activity. 17β-HSD enzymes are primarily involved in the metabolism of steroids at the C-17 position and also of other substrates such as fatty acids, prostaglandins and xenobiotics. In vitro, DHRS10 converts NAD+ into NADH in the presence of oestradiol, testosterone and 5-androstene-3β,17β-diol. Furthermore, the product of oestradiol oxidation, oestrone, was identified in intact cells transfected with a construct plasmid encoding the DHRS10 protein. In situ fluorescence hybridization studies have revealed the cytoplasmic localization of DHRS10. Along with tissue expression data, this suggests a role for DHRS10 in the local inactivation of steroids in the central nervous system and placenta. The crystal structure of the DHRS10 apoenzyme exhibits secondary structure of the SDR (short-chain dehydrogenase/reductase) family: a Rossmann-fold with variable loops surrounding the active site. It also reveals a broad and deep active site cleft into which NAD+ and oestradiol can be docked in a catalytically competent orientation.

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Biedermann, Julia, Matthias Preussler, Marina Conde, Mirko Peitzsch, Susan Richter, Ralf Wiedemuth, Khalil Abou-El-Ardat et al. « Mutant IDH1 Differently Affects Redox State and Metabolism in Glial Cells of Normal and Tumor Origin ». Cancers 11, n^o 12 (16 décembre 2019) : 2028. http://dx.doi.org/10.3390/cancers11122028.

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IDH1R132H (isocitrate dehydrogenase 1) mutations play a key role in the development of low-grade gliomas. IDH1wt converts isocitrate to α-ketoglutarate while reducing nicotinamide adenine dinucleotide phosphate (NADP+), whereas IDH1R132H uses α-ketoglutarate and NADPH to generate the oncometabolite 2-hydroxyglutarate (2-HG). While the effects of 2-HG have been the subject of intense research, the 2-HG independent effects of IDH1R132H are still ambiguous. The present study demonstrates that IDH1R132H expression but not 2-HG alone leads to significantly decreased tricarboxylic acid (TCA) cycle metabolites, reduced proliferation, and enhanced sensitivity to irradiation in both glioblastoma cells and astrocytes in vitro. Glioblastoma cells, but not astrocytes, showed decreased NADPH and NAD+ levels upon IDH1R132H transduction. However, in astrocytes IDH1R132H led to elevated expression of the NAD-synthesizing enzyme nicotinamide phosphoribosyltransferase (NAMPT). These effects were not 2-HG mediated. This suggests that IDH1R132H cells utilize NAD+ to restore NADP pools, which only astrocytes could compensate via induction of NAMPT. We found that the expression of NAMPT is lower in patient-derived IDH1-mutant glioma cells and xenografts compared to IDH1-wildtype models. The Cancer Genome Atlas (TCGA) data analysis confirmed lower NAMPT expression in IDH1-mutant versus IDH1-wildtype gliomas. We show that the IDH1 mutation directly affects the energy homeostasis and redox state in a cell-type dependent manner. Targeting the impairments in metabolism and redox state might open up new avenues for treating IDH1-mutant gliomas.

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Balakin, V., V. Mashinistov et A. Koveria. « Perspective technology of recycling of radioactive contaminated metal based on its melting ». Nuclear and Radiation Safety, n^o 2(78) (7 juin 2018) : 43–48. http://dx.doi.org/10.32918/nrs.2018.2(78).07.

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Melting of the radioactively contaminated metal converts it as a source of ionizing radiation from a surface distribution of radionuclides into the source with their volume distribution. From the surface of the melted metal gamma radiation of a part of radionuclides is emitted, which are in its scope. Alpha and beta radiation are absorbed completely in the metal. To obtain a radiation-safe metal it is necessary that the amount of gamma-emitting radionuclides, which are loaded into the furnace together with the charge, did not exceed the established allowable level. The radiation safety criterion of the melted metal is the maximum value of the gamma radiation power from its surface, the established limit of the individual annual effective radiation dose is not exceeded. There is a need for experimental verification of theoretical results was obtained. The use of this technology will allow the return to industrial production of large amounts of accumulated radioactively contaminated metal and creates conditions for the prevention of environmental violations.

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Immergut, Matthew. « Death at Diamond Mountain ». Nova Religio 17, n^o 1 (février 2013) : 24–37. http://dx.doi.org/10.1525/nr.2013.17.1.24.

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For the past five years, I have engaged in fieldwork and filming a documentary about Diamond Mountain, a community of Western converts to Tibetan Buddhism in southern Arizona under the leadership of Geshe Michael Roach and Lama Christie McNally. The latter was retreat master and, along with her husband Ian Thorson, in the middle of guiding forty students through a three-year, three-month, three-day silent meditation retreat. But when McNally stabbed Thorson, the Diamond Mountain Board asked both to leave. Feigning departure, the couple sneaked into a small cave just outside the Diamond Mountain property, where two months later Thorson died of dehydration. Stories of scandal, cult and death flooded the media. This essay provides an account of these events, the mistrust of my research that emerged because of the media’s stigmatization of the group, and the type of trust-building necessary to continue my research.

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Wang, Feng-Sheng, Re-Wen Wu, Yu-Shan Chen, Jih-Yang Ko, Holger Jahr et Wei-Shiung Lian. « Biophysical Modulation of the Mitochondrial Metabolism and Redox in Bone Homeostasis and Osteoporosis : How Biophysics Converts into Bioenergetics ». Antioxidants 10, n^o 9 (30 août 2021) : 1394. http://dx.doi.org/10.3390/antiox10091394.

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Bone-forming cells build mineralized microstructure and couple with bone-resorbing cells, harmonizing bone mineral acquisition, and remodeling to maintain bone mass homeostasis. Mitochondrial glycolysis and oxidative phosphorylation pathways together with ROS generation meet the energy requirement for bone-forming cell growth and differentiation, respectively. Moderate mechanical stimulations, such as weight loading, physical activity, ultrasound, vibration, and electromagnetic field stimulation, etc., are advantageous to bone-forming cell activity, promoting bone anabolism to compromise osteoporosis development. A plethora of molecules, including ion channels, integrins, focal adhesion kinases, and myokines, are mechanosensitive and transduce mechanical stimuli into intercellular signaling, regulating growth, mineralized extracellular matrix biosynthesis, and resorption. Mechanical stimulation changes mitochondrial respiration, biogenesis, dynamics, calcium influx, and redox, whereas mechanical disuse induces mitochondrial dysfunction and oxidative stress, which aggravates bone-forming cell apoptosis, senescence, and dysfunction. The control of the mitochondrial biogenesis activator PGC-1α by NAD+-dependent deacetylase sirtuins or myokine FNDC/irisin or repression of oxidative stress by mitochondrial antioxidant Nrf2 modulates the biophysical stimulation for the promotion of bone integrity. This review sheds light onto the roles of mechanosensitive signaling, mitochondrial dynamics, and antioxidants in mediating the anabolic effects of biophysical stimulation to bone tissue and highlights the remedial potential of mitochondrial biogenesis regulators for osteoporosis.

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Batsios, Georgios, Celine Taglang, Meryssa Tran, Anne Marie Gillepspie et Pavithra Viswanath. « TMET-20. TERT ACTS VIA FOXO1 TO ALTER REDOX METABOLISM IN BRAIN TUMORS ». Neuro-Oncology 24, Supplement_7 (1 novembre 2022) : vii265—vii266. http://dx.doi.org/10.1093/neuonc/noac209.1025.

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Abstract Telomere maintenance is a fundamental hallmark of cancer. Most tumors maintain telomere length via reactivation of telomerase reverse transcriptase (TERT) expression. Identifying imaging biomarkers of TERT can enable non-invasive assessment of tumor proliferation and response to therapy. Deuterium magnetic resonance spectroscopy (DMRS) following administration of 2H-labeled substrates recently emerged as a novel, clinically translatable method of monitoring metabolic activity in vivo. The goal of this study was to delineate metabolic reprogramming associated with TERT expression and to leverage this information for non-invasive imaging of tumor burden and treatment response in gliomas. Our results indicate that TERT expression is associated with elevated levels of the redox metabolite NADH in glioblastomas and oligodendrogliomas. Mechanistically, TERT expression is associated with inhibitory phosphorylation and cytosolic sequestration of FOXO1. FOXO1, in turn, negatively regulates nicotinamide phosphoribosyl transferase (NAMPT), which is the rate-limiting enzyme in NAD+ biosynthesis. As a result, TERT upregulates NAMPT, resulting in elevated steady-state pools of NAD+ and NADH. Concomitantly, FOXO1 negatively regulates the glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase, which converts NAD+ to NADH. As a result, TERT upregulates the NADH/NAD+ ratio. Since elevated NADH and NADH/NAD+ ratio drive pyruvate conversion to lactate, we then examined whether DMRS-based imaging of [U-2H]-pyruvate metabolism reports on TERT expression in gliomas. Our results indicate that doxycycline-inducible TERT silencing significantly reduces lactate production from [U-2H]-pyruvate in tumor-bearing mice. Importantly, [U-2H]-pyruvate metabolism to lactate differentiates tumor from normal brain in vivo, including at clinical field strength (3T). Furthermore, [U-2H]-pyruvate reports on early response to treatment with TERT inhibitors or with radiochemotherapy in mice bearing orthotopic patient-derived gliomas at early timepoints before radiographic alterations can be visualized by magnetic resonance imaging. Collectively, our studies integrate a mechanistic understanding of TERT biology with innovative imaging that has the potential to improve assessment of tumor burden and treatment response for glioma patients.

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Pampa, Kudigana J., Neratur K. Lokanath, Naoki Kunishima et Ravishankar Vittal Rai. « The first crystal structure of NAD-dependent 3-dehydro-2-deoxy-D-gluconate dehydrogenase fromThermus thermophilusHB8 ». Acta Crystallographica Section D Biological Crystallography 70, n^o 4 (19 mars 2014) : 994–1004. http://dx.doi.org/10.1107/s1399004713034925.

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2-Keto-3-deoxygluconate (KDG) is one of the important intermediates in pectin metabolism. An enzyme involved in this pathway, 3-dehydro-3-deoxy-D-gluconate 5-dehydrogenase (DDGDH), has been identified which converts 2,5-diketo-3-deoxygluconate to KDG. The enzyme is a member of the short-chain dehydrogenase (SDR) family. To gain insight into the function of this enzyme at the molecular level, the first crystal structure of DDGDH fromThermus thermophilusHB8 has been determined in the apo form, as well as in complexes with the cofactor and with citrate, by X-ray diffraction methods. The crystal structures reveal a tight tetrameric oligomerization. The secondary-structural elements and catalytically important residues of the enzyme were highly conserved amongst the proteins of the NAD(P)-dependent SDR family. The DDGDH protomer contains a dinucleotide-binding fold which binds the coenzyme NAD+in an intersubunit cleft; hence, the observed oligomeric state might be important for the catalytic function. This enzyme prefers NAD(H) rather than NADP(H) as the physiological cofactor. A structural comparison of DDGDH with mouse lung carbonyl reductase suggests that a significant difference in the α–loop–α region of this enzyme is associated with the coenzyme specificity. The structural data allow a detailed understanding of the functional role of the conserved catalytic triad (Ser129–Tyr144–Lys148) in cofactor and substrate recognition, thus providing substantial insights into DDGDH catalysis. From analysis of the three-dimensional structure, intersubunit hydrophobic interactions were found to be important for enzyme oligomerization and thermostability.

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Providenti, Miguel A., Jason M. O'Brien, Jürgen Ruff, Alasdair M. Cook et Iain B. Lambert. « Metabolism of Isovanillate, Vanillate, and Veratrate by Comamonas testosteroni Strain BR6020 ». Journal of Bacteriology 188, n^o 11 (1 juin 2006) : 3862–69. http://dx.doi.org/10.1128/jb.01675-05.

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ABSTRACT In Comamonas testosteroni strain BR6020, metabolism of isovanillate (iVan; 3-hydroxy-4-methoxybenzoate), vanillate (Van; 4-hydroxy-3-methoxybenzoate), and veratrate (Ver; 3,4-dimethoxybenzoate) proceeds via protocatechuate (Pca; 3,4-dihydroxybenzoate). A 13.4-kb locus coding for the catabolic enzymes that channel the three substrates to Pca was cloned. O demethylation is mediated by the phthalate family oxygenases IvaA (converts iVan to Pca and Ver to Van) and VanA (converts Van to Pca and Ver to iVan). Reducing equivalents from NAD(P)H are transferred to the oxygenases by the class IA oxidoreductase IvaB. Studies using whole cells, cell extracts, and reverse transcriptase PCR showed that degradative activity and expression of vanA, ivaA, and ivaB are inducible. In succinate- and Pca-grown cells, there is negligible degradative activity towards Van, Ver, and iVan and little to no expression of vanA, ivaA, and ivaB. Growth on Van or Ver results in production of oxygenases with activity towards Van, Ver, and iVan and expression of vanA, ivaA, and ivaB. With iVan-grown cultures, ivaA and ivaB are expressed, and in assays with whole cells, production of the iVan oxygenase is observed, but there is little activity towards Van or Ver. In cell extracts, though, Ver metabolism is observed, which suggests that the system mediating iVan uptake in whole cells does not mediate Ver uptake.

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Skory, Christopher D. « Isolation and Expression of Lactate Dehydrogenase Genes from Rhizopus oryzae ». Applied and Environmental Microbiology 66, n^o 6 (1 juin 2000) : 2343–48. http://dx.doi.org/10.1128/aem.66.6.2343-2348.2000.

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ABSTRACT Rhizopus oryzae is used for industrial production of lactic acid, yet little is known about the genetics of this fungus. In this study I cloned two genes, ldhA and ldhB, which code for NAD+-dependent l-lactate dehydrogenases (LDH) (EC 1.1.1.27 ), from a lactic acid-producing strain of R. oryzae. These genes are similar to each other and exhibit more than 90% nucleotide sequence identity and they contain no introns. This is the first description of ldh genes in a fungus, and sequence comparisons revealed that these genes are distinct from previously isolated prokaryotic and eukaryotic ldh genes. Protein sequencing of the LDH isolated from R. oryzae during lactic acid production confirmed that ldhA codes for a 36-kDa protein that converts pyruvate to lactate. Production of LdhA was greatest when glucose was the carbon source, followed by xylose and trehalose; all of these sugars could be fermented to lactic acid. Transcripts fromldhB were not detected when R. oryzae was grown on any of these sugars but were present when R. oryzae was grown on glycerol, ethanol, and lactate. I hypothesize thatldhB encodes a second NAD+-dependent LDH that is capable of converting l-lactate to pyruvate and is produced by cultures grown on these nonfermentable substrates. BothldhA and ldhB restored fermentative growth toEscherichia coli (ldhA pfl) mutants so that they grew anaerobically and produced lactic acid.

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Homer, Michael W. « Seeking Primitive Christianity in the Waldensian Valleys : Protestants, Mormons, Adventists and Jehovah's Witnesses in Italy ». Nova Religio 9, n^o 4 (1 mai 2006) : 5–33. http://dx.doi.org/10.1525/nr.2006.9.4.005.

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During the nineteenth century, Protestant clergymen (Anglican, Presbyterian, and Baptist) as well as missionaries for new religious movements (Mormons, Seventh-day Adventists and Jehovah's Witnesses) believed that Waldensian claims to antiquity were important in their plans to spread the Reformation to Italy. The Waldensians, who could trace their historical roots to Valdes in 1174, developed an ancient origins thesis after their union with the Protestant Reformation in the sixteenth century. This thesis held that their community of believers had preserved the doctrines of the primitive church. The competing churches of the Reformation believed that the Waldensians were "destined to fulfill a most important mission in the Evangelization of Italy" and that they could demonstrate, through Waldensian history and practices, that their own claims and doctrines were the same as those taught by the primitive church. The new religious movements believed that Waldensians were the best prepared in Italy to accept their new revelations of the restored gospel. In fact, the initial Mormon, Seventh-day Adventist, and Jehovah's Witness converts in Italy were Waldensians. By the end of the century, however, Catholic, Protestant, and Waldensian scholars had debunked the thesis that Waldensians were proto-Protestants prior to Luther and Calvin.

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Murken, Sebastian, et Sussan Namini. « Childhood Familial Experiences as Antecedents of Adult Membership in New Religious Movements : A Literature Review ». Nova Religio 10, n^o 4 (1 mai 2007) : 17–37. http://dx.doi.org/10.1525/nr.2007.10.4.17.

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Is it possible to identify specific familial patterns as antecedents of adult membership in new religious movements? Can the choice of an NRM be predicted by the childhood experiences of individuals joining such movements? This international literature review seeks to answer these questions, investigating the assumption that early family experiences affect adults' decisions to join NRMs. It includes empirical studies that have been written in English, German and French since 1970, and gives an overview of findings on childhood family structures, including parents and siblings, as well as early family relationships and atmospheres. On the whole, the studies from different countries and decades support the hypothesis that early family experiences have an impact on adult membership in NRMs. However, it seems that individuals with different early experiences are attracted to different kinds of groups. Whereas many studies found problematic family backgrounds and absent fathers in converts' biographies, suggesting a compensatory function of membership, some point to a continuation or restoration of early experiences. More interdisciplinary comparative research on NRMs is needed to gain a better understanding of the psychodynamic processes and psychological offers of different groups.

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Kempster, Sarah L., Gusztav Belteki, Alison J. Forhead, Abigail L. Fowden, Robert D. Catalano, Brian Y. Lam, Ian McFarlane, D. Stephen Charnock-Jones et Gordon C. S. Smith. « Developmental control of the Nlrp6 inflammasome and a substrate, IL-18, in mammalian intestine ». American Journal of Physiology-Gastrointestinal and Liver Physiology 300, n^o 2 (février 2011) : G253—G263. http://dx.doi.org/10.1152/ajpgi.00397.2010.

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The inflammasome is a multiprotein complex whose formation is triggered when a NOD-like receptor binds a pathogen ligand, resulting in activated caspase-1, which converts certain interleukins (IL-1β, IL-18, and IL-33) to their active forms. There is currently no information on regulation of this system around the time of birth. We employed transcript profiling of fetal rat intestinal and lung RNA at embryonic days 16 (E16) and 20 (E20) with out-of-sample validation using quantitative RT-PCR. Transcript profiling and quantitative RT-PCR demonstrated that transcripts of core components of the NOD-like receptor Nlrp6 inflammasome ( Nlrp6, Pycard, Caspase-1) and one of its substrates, IL-18, were increased at E20 compared with E16 in fetal intestine and not lung. Immunohistochemistry demonstrated increased Pycard in intestinal epithelium. Western blotting demonstrated that IL-18 was undetectable at E16, clearly detectable at E20 in its inactive form, and detectable postnatally in both its inactive and active form. Dramatic upregulation of IL-18 was also observed in the fetal sheep jejunum in late gestation ( P = 0.006). Transcription factor binding analysis of the rat array data revealed an overrepresentation of nuclear transcription factor binding sites peroxisome proliferator-activated receptor γ (PPAR-γ) and retinoid X receptor-α and chicken ovalbumin upstream promoter transcription factor 1 in the region 1,000 bp upstream of the transcription start site. Rosiglitazone, a PPAR-γ agonist, more than doubled levels of NLRP6 mRNA in human intestinal epithelial (Caco2) cells. These observations provide the first evidence, to our knowledge, linking activity of PPAR-γ to expression of a NOD-like receptor and adds to a growing body of evidence linking pattern recognition receptors of the innate immune system and intestinal colonization.

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Hattula, M. Tapani, Harriet C. Wallin, R. Andersen, K. Blomberg, K. Carlsson, B. Hald, E. Huge-Jensen et al. « Enzymatic Determination of Free Glutamic Acid in Dried Soups and in Minced Sausages : NMKL1 Collaborative Study ». Journal of AOAC INTERNATIONAL 74, n^o 6 (1 novembre 1991) : 921–25. http://dx.doi.org/10.1093/jaoac/74.6.921.

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Abstract An enzymatic method for the determination of free glutamic acid in meat products and dried soups was collaboratively studied in 11 laboratories. In the presence of the enzyme glutamate dehydrogenase, L-giutamic acid is oxidatively deaminated by nicotinamide adenine dinucleotide (NAD) to 2-oxoglutarate. In a reaction catalyzed by diaphorase, the NADH thus formed converts 2-(p-iodophenyl)-3-(p-nitrophenyl)-5-phenyltetrazolium chloride to a formazan, which is measured in the visible range at 492 nm. Fourteen samples (7 samples of minced sausage and 7 samples of dried cauliflower soup) with glutamate contents varying between 0.4 and 16 g/kg were included In the study. Materials were distributed to participants as blind duplicates and as split level pairs. The mean relative standard deviation (RSDR) for reproducibility for the dried soup material containing glutamate between 7 and 16 g/kg was 4.6%. RSDR values for samples of minced sausage containing glutamate at lower levels (0.4-1.3 g/kg) were between 12 and 16%.

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Taneera, Jalal, Emma Smith, Mikael Sigvardsson, Emil Hansson, Urban Lindahl, Inga-Lill Martensson et Sten Eirik Jacobsen. « Notch Activation Converts B Cells into a T Cell Fate at the Earliest Stages of B Cell Committed Progenitors. » Blood 106, n^o 11 (16 novembre 2005) : 3151. http://dx.doi.org/10.1182/blood.v106.11.3151.3151.

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Abstract Notch activation has been suggested to promote T cell development at the expense of B cell commitment at the level of a common lymphoid progenitor prior to B cell commitment. Here, we explored the possibility that Notch activation might be able to switch the fate of already committed B cell progenitors towards T cell development upon Notch activation. To address this we overexpressed constitutively activated Notch-3 (N3IC) in B cell progenitors purified from transgenic mice in which human CD25 is expressed under control of the λ5 promoter. Strikingly, whereas untransduced and control transduced B220+λ5+CD3− B cell progenitors gave rise exclusively to B cells, CD4+ and CD8+ T cells but no B cells were derived from N3IC-transduced cells when transplanted into sublethally irradiated NOD-SCID mice. Gene expression profiling demonstrated that untransduced B220+ λ5+CD3− B cell progenitors expressed λ5 and CD19 but not the T cell specific genes GATA-3, lck and pTα, whereas CD3+ T cells derived from N3IC-transduced B220+λ5+CD3−cells failed to express λ5 and CD19, but were positive for GATA-3, lck and pTα expression as well as a and b T cell rearrangement. Furthermore, DJ rearrangements were detected at very low levels in CD3+ cells isolated from normal non-transduced BM, but were more abundant in the N3IC-transduced CD3+ BM cells. Noteworthy, N3IC-transduced B220+λ5+CD3−CD19+ proB cell progenitors failed to generate B as well as T cells, whereas N3IC-transduced B220+λ5+CD3−CD19− pre-proB cells produced exclusively T cells, even when evaluated at low cell numbers. In conclusion Notch activation can switch committed B cell progenitors from a B cell to a T cell fate, but this plasticity is lost at the Pro-B cell stage, upon upregulation of CD19 expression.

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Dachevsky, Fernando. « Acumulación de capital y particularidades en el nacionalismo petrolero argentino ». Anuario Centro de Estudios Económicos de la Empresa y el Desarrollo, n^o 18 (3 février 2022) : 23–54. http://dx.doi.org/10.56503/anuario/nro.18(14)pp.23-54.

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Los procesos de nacionalización aparecen de manera recurrente en la historia petrolera mundial. Se trata por ello de un sector que tiende a convertirse en causa del nacionalismo. El presente trabajo se propone examinar particularidades del nacionalismo petrolero argentino. Para ello analizamos sus principales elaboraciones intelectuales a luz de los conflictos principales que generaba la acumulación de capital en dicho sector. Buscamos así identificar desde qué problemáticas se formuló la necesidad de la nacionalización del petróleo en este país. Recuperando la experiencia de los principales países exportadores, comenzamos reconociendo aquellos determinantes propios de la industria petrolera que la convierten en objeto de especial interés para el nacionalismo. Identificamos la centralidad del problema territorial, así como también los antagonismos que implica. Respecto del caso argentino, reconocemos dos problemáticas especiales: 1) el temprano cuestionamiento del capital privado extranjero; y 2) el retroceso del nacionalismo petrolero en un contexto mundial de nacionalizaciones. Abordando estos puntos nos proponemos contribuir a la comprensión de un sector que históricamente se desenvolvió bajo la dicotomía entre lo público y lo privado.

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Zhang, Jun-Jie, Hong Liu, Yi Xiao, Xian-En Zhang et Ning-Yi Zhou. « Identification and Characterization of Catabolic para-Nitrophenol 4-Monooxygenase and para-Benzoquinone Reductase from Pseudomonas sp. Strain WBC-3 ». Journal of Bacteriology 191, n^o 8 (13 février 2009) : 2703–10. http://dx.doi.org/10.1128/jb.01566-08.

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ABSTRACT Pseudomonas sp. strain WBC-3 utilizes para-nitrophenol (PNP) as a sole source of carbon, nitrogen, and energy. In order to identify the genes involved in this utilization, we cloned and sequenced a 12.7-kb fragment containing a conserved region of NAD(P)H:quinone oxidoreductase genes. Of the products of the 13 open reading frames deduced from this fragment, PnpA shares 24% identity to the large component of a 3-hydroxyphenylacetate hydroxylase from Pseudomonas putida U and PnpB is 58% identical to an NAD(P)H:quinone oxidoreductase from Escherichia coli. Both PnpA and PnpB were purified to homogeneity as His-tagged proteins, and they were considered to be a monomer and a dimer, respectively, as determined by gel filtration. PnpA is a flavin adenine dinucleotide-dependent single-component PNP 4-monooxygenase that converts PNP to para-benzoquinone in the presence of NADPH. PnpB is a flavin mononucleotide-and NADPH-dependent p-benzoquinone reductase that catalyzes the reduction of p-benzoquinone to hydroquinone. PnpB could enhance PnpA activity, and genetic analyses indicated that both pnpA and pnpB play essential roles in PNP mineralization in strain WBC-3. Furthermore, the pnpCDEF gene cluster next to pnpAB shares significant similarities with and has the same organization as a gene cluster responsible for hydroquinone degradation (hapCDEF) in Pseudomonas fluorescens ACB (M. J. Moonen, N. M. Kamerbeek, A. H. Westphal, S. A. Boeren, D. B. Janssen, M. W. Fraaije, and W. J. van Berkel, J. Bacteriol. 190:5190-5198, 2008), suggesting that the genes involved in PNP degradation are physically linked.

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González, Eva, M. Rosario Fernández, Didac Marco, Eduard Calam, Lauro Sumoy, Xavier Parés, Sylvie Dequin et Josep A. Biosca. « Role of Saccharomyces cerevisiae Oxidoreductases Bdh1p and Ara1p in the Metabolism of Acetoin and 2,3-Butanediol ». Applied and Environmental Microbiology 76, n^o 3 (4 décembre 2009) : 670–79. http://dx.doi.org/10.1128/aem.01521-09.

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ABSTRACT NAD-dependent butanediol dehydrogenase (Bdh1p) from Saccharomyces cerevisiae reversibly transforms acetoin to 2,3-butanediol in a stereospecific manner. Deletion of BDH1 resulted in an accumulation of acetoin and a diminution of 2,3-butanediol in two S. cerevisiae strains under two different growth conditions. The concentrations of (2R,3R)-2,3-butanediol are mostly dependent on Bdh1p activity, while those of (meso)-2,3-butanediol are also influenced by the activity of NADP(H)-dependent oxidoreductases. One of them has been purified and shown to be d-arabinose dehydrogenase (Ara1p), which converts (R/S)-acetoin to meso-2,3-butanediol and (2S,3S)-2,3-butanediol. Deletion of BDH2, a gene adjacent to BDH1, whose encoded protein is 51% identical to Bdh1p, does not significantly alter the levels of acetoin or 2,3-butanediol in comparison to the wild-type strain. Furthermore, we have expressed Bdh2p with a histidine tag and have shown it to be inactive toward 2,3-butanediol. A whole-genome expression analysis with microarrays demonstrates that BDH1 and BDH2 are reciprocally regulated.

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Gonzalez, Sarah, Ying‐Hsang Liu, Sue Yeon Syn, Stephann Makri, Lynn Silipigni Connaway, Lisa M. Given, Jenna Hartel et Kate McDowell. « Storytelling for Translational Research Impact ». Proceedings of the Association for Information Science and Technology 60, n^o 1 (octobre 2023) : 861–65. http://dx.doi.org/10.1002/pra2.879.

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ABSTRACTTranslational research converts research knowledge into practical wisdom for a community (What is Translational Research, n.d.). Storytelling for translational research means that the researcher knows the audience, crafts a narrative, sticks to the plot, and imparts wisdom in a meaningful way – all elements of a good story from a good storyteller. In this hybrid panel and workshop, led by Stephann Makri and other members of the ASIS&T Research Engagement Committee, our successful researchers/storytellers will illustrate how a good translational research impact story is structured. Then, our storytelling experts will help participants craft their own research narratives to put translational research storytelling into practice for their own research stories. Dr. Kate McDowell, panelist and storytelling expert, teaches both storytelling and data storytelling courses, and is the 2022 recipient of the ASIS&T Outstanding Information Science Teacher Award. She states: “When research successfully translates into legislative or policy changes, it always comes down to a shared narrative experience. The story emerges in the dynamic interaction between the teller and the audience.” The aim of this session is to create confident storytellers.

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