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Vadim Gladyshev Publications

Articles 91 - 110 of 110

Full-Text Articles in Biochemistry, Biophysics, and Structural Biology

Selenoproteins And Selenocysteine Insertion System In The Model Plant Cell System, Chlamydomonas Reinhardtii, Sergey V. Novoselov, Mahadev Rao, Natalia V. Onoshko, Huijun Zhi, Gregory V. Kryukov, Youbin Xiang, Donald P. Weeks, Dolph A. Hatfield, Vadim Gladyshev Jul 2002

Selenoproteins And Selenocysteine Insertion System In The Model Plant Cell System, Chlamydomonas Reinhardtii, Sergey V. Novoselov, Mahadev Rao, Natalia V. Onoshko, Huijun Zhi, Gregory V. Kryukov, Youbin Xiang, Donald P. Weeks, Dolph A. Hatfield, Vadim Gladyshev

Vadim Gladyshev Publications

Known eukaryotic selenocysteine (Sec)-containing proteins are animal proteins, whereas selenoproteins have not been found in yeast and plants. Surprisingly, we detected selenoproteins in a member of the plant kingdom, Chlumydomonas reinhardtii, and directly identified two of them as phospholipid hydroperoxide glutathione peroxidase and selenoprotein W homologs. Moreover, a selenocysteyl-tRNA was isolated that recognized specifically the Sec codon UGA. Subsequent gene cloning and bioinformatics analyses identified eight additional selenoproteins, including methionine-Ssulfoxide reductase, a selenoprotein specific to Chlumydomonas. Chlumydomonas selenoprotein genes contained selenocysteine insertion sequence (SECIS) elements that were similar, but not identical, to those of animals. These SECIS elements could direct …

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Minireview: How Selenium Has Altered Our Understanding Of The Genetic Code, Dolph L. Hatfield, Vadim Gladyshev Jun 2002

Minireview: How Selenium Has Altered Our Understanding Of The Genetic Code, Dolph L. Hatfield, Vadim Gladyshev

Vadim Gladyshev Publications

Selenium is an essential micronutrient in the diet of many life forms, including humans and other mammals. Significant health benefits have been attributed to this element. It is rapidly becoming recognized as one of the more promising cancer chemopreventive agents (19), and there are strong indications that it has a role in reducing viral expression (4), in preventing heart disease and other cardiovascular and muscle disorders (23), and in delaying the progression of AIDS in human immunodeficiency virus-infected patients (3). Additional evidence suggests that selenium may have a role in mammalian development (51), in immune function (70), in male reproduction …

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Mammalian Selenoprotein In Which Selenocysteine (Sec) Incorporation Is Supported By A New Form Of Sec Insertion Sequence Element, Konstantin V. Korotkov, Sergey V. Novoselov, Dolph L. Hatfield, Vadim Gladyshev Mar 2002

Mammalian Selenoprotein In Which Selenocysteine (Sec) Incorporation Is Supported By A New Form Of Sec Insertion Sequence Element, Konstantin V. Korotkov, Sergey V. Novoselov, Dolph L. Hatfield, Vadim Gladyshev

Vadim Gladyshev Publications

Selenocysteine (Sec), the 21st amino acid in protein, is encoded by UGA. The Sec insertion sequence (SECIS) element, which is the stem-loop structure present in 3’ untranslated regions (UTRs) of eukaryotic selenoprotein- encoding genes, is essential for recognition of UGA as a codon for Sec rather than as a stop signal. We now report the identification of a new eukaryotic selenoprotein, designated selenoprotein M (SelM). The 3-kb human SelM-encoding gene has five exons and is located on chromosome 22 but has not been correctly identified by either Celera or the public Human Genome Project. We characterized human and mouse SelM …

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Selenium Metabolism In Drosophila, F. Javier Martin-Romero, Gregory V. Kryukov, Alexei V. Lobanov, Bradley A. Carlson, Byeong Jae Lee, Vadim N. Gladyshev, Dolph L. Hatfield Aug 2001

Selenium Metabolism In Drosophila, F. Javier Martin-Romero, Gregory V. Kryukov, Alexei V. Lobanov, Bradley A. Carlson, Byeong Jae Lee, Vadim N. Gladyshev, Dolph L. Hatfield

Vadim Gladyshev Publications

Selenocysteine is a rare amino acid in protein that is encoded by UGA with the requirement of a downstream mRNA stem-loop structure, the selenocysteine insertion sequence element. To detect selenoproteins in Drosophila, the entire genome was analyzed with a novel program that searches for selenocysteine insertion sequence elements, followed by selenoprotein gene signature analyses. This computational screen and subsequent metabolic labeling with 75Se and characterization of selenoprotein mRNA expression resulted in identification of three selenoproteins: selenophosphate synthetase 2 and novel G-rich and BthD selenoproteins that had no homology to known proteins. To assess a biological role for these …

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Identification And Characterization Of A New Mammalian Glutaredoxin (Thioltransferase), Grx2, Vadim N. Gladyshev, Aimin Liu, Sergey V. Novoselov, Konstantin Krysan, Qi-An Sun, Valentin M. Kryukov, Gregory V. Kryukov, Marjorie F. Lou Aug 2001

Identification And Characterization Of A New Mammalian Glutaredoxin (Thioltransferase), Grx2, Vadim N. Gladyshev, Aimin Liu, Sergey V. Novoselov, Konstantin Krysan, Qi-An Sun, Valentin M. Kryukov, Gregory V. Kryukov, Marjorie F. Lou

Vadim Gladyshev Publications

A thiol/disulfide oxidoreductase component of the GSH system, glutaredoxin (Grx), is involved in the reduction of GSH-based mixed disulfides and participates in a variety of cellular redox pathways. A single cytosolic Grx (Grx1) was previously described in mammals. We now report identification and characterization of a second mammalian Grx, designated Grx2. Grx2 exhibited 36% identity with Grx1 and had a disulfide active center containing the Cys-Ser-Tyr-Cys motif. Grx2 was encoded in the genomes of mammals and birds and expressed in a variety of cell types. The gene for human Grx2 consisted of four exons and three introns, spanned 10 kilobase …

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Selective Inhibition Of Selenocysteine Trna Maturation And Selenoprotein Synthesis In Transgenic Mice Expressing Isopentenyladenosine-Deficient Selenocysteine Trna, Mohamed E. Moustafa, Bradley A. Carlson, Muhammed A. El-Saadani, Gregory V. Kryukov, Qi-An Sun, John W. Harney, Kristina E. Hill, Gerald F. Combs, Lionel Feigenbaum, David B. Mansur, Raymond F. Burk, Marla J. Berry, Alan M. Diamond, Byeong Jae Lee, Vadim Gladyshev, Dolph A. Hatfield Jun 2001

Selective Inhibition Of Selenocysteine Trna Maturation And Selenoprotein Synthesis In Transgenic Mice Expressing Isopentenyladenosine-Deficient Selenocysteine Trna, Mohamed E. Moustafa, Bradley A. Carlson, Muhammed A. El-Saadani, Gregory V. Kryukov, Qi-An Sun, John W. Harney, Kristina E. Hill, Gerald F. Combs, Lionel Feigenbaum, David B. Mansur, Raymond F. Burk, Marla J. Berry, Alan M. Diamond, Byeong Jae Lee, Vadim Gladyshev, Dolph A. Hatfield

Vadim Gladyshev Publications

Selenocysteine (Sec) tRNA (tRNA [Ser]Sec) serves as both the site of Sec biosynthesis and the adapter molecule for donation of this amino acid to protein. The consequences on selenoprotein biosynthesis of overexpressing either the wild type or a mutant tRNA [Ser]Sec lacking the modified base, isopentenyladenosine, in its anticodon loop were examined by introducing multiple copies of the corresponding tRNA [Ser]Sec genes into the mouse genome. Overexpression of wild-type tRNA [Ser]Sec did not affect selenoprotein synthesis. In contrast, the levels of numerous selenoproteins decreased in mice expressing isopentenyladenosine-deficient (i6A-) tRNA [Ser]Sec in a protein- and …

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Chapter 13. The 15 Kda Selenoprotein (Sepl5): Functional Studies And A Role In Cancer Etiology, Vadim Gladyshev, Alan M. Diamond, Dolph L. Hatfield May 2001

Chapter 13. The 15 Kda Selenoprotein (Sepl5): Functional Studies And A Role In Cancer Etiology, Vadim Gladyshev, Alan M. Diamond, Dolph L. Hatfield

Vadim Gladyshev Publications

The 15 kDa selenoprotein (Sepl5) is one of several recently identified selenoproteins. It contains a single selenocysteine residue in the middle of a 162-amino acid open reading frame and has no detectable homology to known proteins. The human Sepl5 gene spans 5 1 kb, has 5 exons and is located on chromosome 1 at position p3 1. The gene contains two single nucleotide polymorphisms in the 3'-untranslated region (3'-UTR) including one in the SECIS element, that are distributed differently between Caucasians and African Americans. Sep15 localizes to the endoplasmic reticulum where it is tightly bound to UDP-glucose:glycoprotein glucosyltransferase, a protein …

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Chapter 25. Selenium In Biology And Human Health: Controversies And Perspectives, Vadim Gladyshev May 2001

Chapter 25. Selenium In Biology And Human Health: Controversies And Perspectives, Vadim Gladyshev

Vadim Gladyshev Publications

Important unresolved questions raised by the contributors of this book and addressing roles of selenium in biology and human health are discussed. Resolving major scientific controversies in the field should further highlight a bright future for selenium in fundamental science, biotechnology and medicine.

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Association Between The 15-Kda Selenoprotein And Udp-Glucose:Glycoprotein Glucosyltransferase In The Endoplasmic Reticulum Of Mammalian Cells, Konstantin V. Korotkov, Easwari Kumaraswamy, You Zhou, Dolph L. Hatfield, Vadim N. Gladyshev May 2001

Association Between The 15-Kda Selenoprotein And Udp-Glucose:Glycoprotein Glucosyltransferase In The Endoplasmic Reticulum Of Mammalian Cells, Konstantin V. Korotkov, Easwari Kumaraswamy, You Zhou, Dolph L. Hatfield, Vadim N. Gladyshev

Vadim Gladyshev Publications

Mammalian selenocysteine-containing proteins characterized with respect to function are involved in redox processes and exhibit distinct expression patterns and cellular locations. A recently identified 15-kDa selenoprotein (Sep15) has no homology to previously characterized proteins, and its function is not known. Here we report the intracellular localization and identification of a binding partner for this selenoprotein which implicate Sep15 in the regulation of protein folding. The native Sep15 isolated from rat prostate and mouse liver occurred in a complex with a 150-kDa protein. The latter protein was identified as UDP-glucose:glycoprotein glucosyltransferase (UGTR), the endoplasmic reticulum (ER)-resident protein, which was previously shown …

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Heterogeneity Within Animal Thioredoxin Reductases, Qi-An Sun, Francesca Zappacosta, Valentina M. Factor, Peter J. Wirth, Dolph L. Hatfield, Vadim N. Gladyshev Feb 2001

Heterogeneity Within Animal Thioredoxin Reductases, Qi-An Sun, Francesca Zappacosta, Valentina M. Factor, Peter J. Wirth, Dolph L. Hatfield, Vadim N. Gladyshev

Vadim Gladyshev Publications

Animal thioredoxin reductases (TRs) are selenocysteine- containing flavoenzymes that utilize NADPH for reduction of thioredoxins and other protein and nonprotein substrates. Three types of mammalian TRs are known, with TR1 being a cytosolic enzyme, and TR3, a mitochondrial enzyme. Previously characterized TR1 and TR3 occurred as homodimers of 55–57-kDa subunits. We report here that TR1 isolated from mouse liver, mouse liver tumor, and a human T-cell line exhibited extensive heterogeneity as detected by electrophoretic, immunoblot, and mass spectrometry analyses. In particular, a 67-kDa band of TR1 was detected. Furthermore, a novel form of mouse TR1 cDNA encoding a 67-kDa selenoprotein …

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Structure-Expression Relationships Of The 15-Kda Selenoprotein Gene, Easwari Kumaraswamy, Andrey Malyhk, Konstantin V. Korotkov, Sergei Kozyavkin, Yajun Hu, Byeong J. Lee, Dolph L. Hatfield, Alan M. Diamond, Vadim N. Gladyshev Nov 2000

Structure-Expression Relationships Of The 15-Kda Selenoprotein Gene, Easwari Kumaraswamy, Andrey Malyhk, Konstantin V. Korotkov, Sergei Kozyavkin, Yajun Hu, Byeong J. Lee, Dolph L. Hatfield, Alan M. Diamond, Vadim N. Gladyshev

Vadim Gladyshev Publications

Selenium has been implicated in cancer prevention, but the mechanism and possible involvement of selenoproteins in this process are not understood. To elucidate whether the 15-kDa selenoprotein may play a role in cancer etiology, the complete sequence of the human 15-kDa protein gene was determined, and various characteristics associated with expression of the protein were examined in normal and malignant cells and tissues. The 51-kilobase pair gene for the 15-kDa selenoprotein consisted of five exons and four introns and was localized on chromosome 1p31, a genetic locus commonly mutated or deleted in human cancers. Two stemloop structures resembling selenocysteine insertion …

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New Mammalian Selenocysteine-Containing Proteins Identified With An Algorithm That Searches For Selenocysteine Insertion Sequence Elements, Gregory V. Kryukov, Valentin M. Kryukov, Vadim N. Gladyshev Nov 1999

New Mammalian Selenocysteine-Containing Proteins Identified With An Algorithm That Searches For Selenocysteine Insertion Sequence Elements, Gregory V. Kryukov, Valentin M. Kryukov, Vadim N. Gladyshev

Vadim Gladyshev Publications

Mammalian selenium-containing proteins identified thus far contain selenium in the form of a selenocysteine residue encoded by UGA. These proteins lack common amino acid sequence motifs, but 3’-untranslated regions of selenoprotein genes contain a common stem-loop structure, selenocysteine insertion sequence (SECIS) element, that is necessary for decoding UGA as selenocysteine rather than a stop signal. We describe here a computer program, SECISearch, that identifies mammalian selenoprotein genes by recognizing SECIS elements on the basis of their primary and secondary structures and free energy requirements. When SECISearch was applied to search human dbEST, two new mammalian selenoproteins, designated SelT and SelR, …

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Redox Regulation Of Cell Signaling By Selenocysteine In Mammalian Thioredoxin Reductases, Qi-An Sun, Yalin Wu, Francesca Zappacosta, Kuan-Teh Jeang, Byeong Jae Lee, Dolph L. Hatfield, Vadim N. Gladyshev Aug 1999

Redox Regulation Of Cell Signaling By Selenocysteine In Mammalian Thioredoxin Reductases, Qi-An Sun, Yalin Wu, Francesca Zappacosta, Kuan-Teh Jeang, Byeong Jae Lee, Dolph L. Hatfield, Vadim N. Gladyshev

Vadim Gladyshev Publications

The intracellular generation of reactive oxygen species, together with the thioredoxin and glutathione systems, is thought to participate in redox signaling in mammalian cells. The activity of thioredoxin is dependent on the redox status of thioredoxin reductase (TR), the activity of which in turn is dependent on a selenocysteine residue. Two mammalian TR isozymes (TR2 and TR3), in addition to that previously characterized (TR1), have now been identified in humans and mice. All three TR isozymes contain a selenocysteine residue that is located in the penultimate position at the carboxyl terminus and which is encoded by a UGA codon. The …

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Levels Of Major Selenoproteins In T Cells Decrease During Hiv Infection And Low Molecular Mass Selenium Compounds Increase, Vadim Gladyshev, Thressa C. Stadtman, Dolph L. Hatfield, Kuan-Teh Jeang Feb 1999

Levels Of Major Selenoproteins In T Cells Decrease During Hiv Infection And Low Molecular Mass Selenium Compounds Increase, Vadim Gladyshev, Thressa C. Stadtman, Dolph L. Hatfield, Kuan-Teh Jeang

Vadim Gladyshev Publications

It has been observed previously that plasma selenium and glutathione levels are subnormal in HIV-infected individuals, and plasma glutathione peroxidase activity is decreased. Under these conditions the survival rate of AIDS patients is reduced significantly. In the present study, using 75Se-labeled human Jurkat T cells, we show that the levels of four 75Se-containing proteins are lower in HIV-infected cell populations than in uninfected cells. These major selenoproteins migrated as 57-, 26-, 21-, and 15-kDa species on SDS/PAGE gels. In our earlier studies, the 57-kDa protein was purified from T cells and identified as a subunit of thioredoxin reductase. …

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Selenocysteine-Containing Proteins In Mammals, Vadim N. Gladyshev, Dolph L. Hatfield Nov 1998

Selenocysteine-Containing Proteins In Mammals, Vadim N. Gladyshev, Dolph L. Hatfield

Vadim Gladyshev Publications

Since the recent discovery of selenocysteine as the 21st amino acid in protein, the field of selenium biology has rapidly expanded. Twelve mammalian selenoproteins have been characterized to date and each contains selenocysteine that is incorporated in response to specific UGA code words. These selenoproteins have different cellular functions, but in those selenoproteins for which the function is known, selenocysteine is located at the active center. The presence of selenocysteine at critical sites in naturally occurring selenoproteins provides an explanation for the important role of selenium in human health and development. This review describes known mammalian selenoproteins and discusses recent …

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A New Human Selenium-Containing Protein, Vadim N. Gladyshev, Kuan Teh Jeang, John C. Wootton, Dolph L. Hatfield Apr 1998

A New Human Selenium-Containing Protein, Vadim N. Gladyshev, Kuan Teh Jeang, John C. Wootton, Dolph L. Hatfield

Vadim Gladyshev Publications

Selenium which occurs in proteins as the amino acid, selenocysteine, is essential for numerous biological processes and for human health. A prominent 75Se-labeled protein detected in human T-cells migrated as a 15-kDa band by SDS-polyacrylamide gel electrophoresis. This protein subunit was purified and subjected to tryptic digestion and peptide sequence analyses. Sequences of tryptic peptides derived from the protein corresponded to a human placental gene sequence containing an open reading frame of 162 residues and a readthrough in-frame TGA codon. Three different peptide sequences of the 15-kDa protein corresponded to a nucleotide sequence located downstream of this codon, suggesting …

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Selenocysteine, Identified As The Penultimate C-Terminal Residue In Human T-Cell Thioredoxin Reductase, Corresponds To Tga In The Human Placental Gene, Vadim Gladyshev, Kuan-Teh Jeang, Thressa C. Stadtman Jun 1996

Selenocysteine, Identified As The Penultimate C-Terminal Residue In Human T-Cell Thioredoxin Reductase, Corresponds To Tga In The Human Placental Gene, Vadim Gladyshev, Kuan-Teh Jeang, Thressa C. Stadtman

Vadim Gladyshev Publications

The possible relationship of selenium to immunological function which has been suggested for decades was investigated in studies on selenuim metabolism in human T cells. One of the major 75Se-labeled selenoproteins detected was purified to homogeneity and shown to be a homodimer of 55-kDa subunits. Each subunit contained about 1 FAD and at least 0.74 Se. This protein proved to be thioredoxin reductase (TR) on the basis of its catalytic activities, cross-reactivity with anti-rat liver TR antibodies, and sequence identities of several tryptic peptides with the published deduced sequence of human placental TR. Physicochemical characteristics of T-cell TR were …

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Characterization Of Crystalline Formate Dehydrogenase H From Escherichia Coli, Vadim N. Gladyshev, Jeffrey C. Boyington, Sergei V. Khangulov, David Grahame, Thressa C. Stadtman, Peter D. Sun Apr 1996

Characterization Of Crystalline Formate Dehydrogenase H From Escherichia Coli, Vadim N. Gladyshev, Jeffrey C. Boyington, Sergei V. Khangulov, David Grahame, Thressa C. Stadtman, Peter D. Sun

Vadim Gladyshev Publications

The selenocysteine-containing formate dehydrogenase H (FDH) is an 80-kDa component of the Escherichia coli formate-hydrogen lyase complex. The molybdenumcoordinated selenocysteine is essential for catalytic activity of the native enzyme. FDH in dilute solutions (30 μg/ml) was rapidly inactivated at basic pH or in the presence of formate under anaerobic conditions, but at higher enzyme concentrations ( 3 mg/ml) the enzyme was relatively stable. The formate-reduced enzyme was extremely sensitive to air inactivation under all conditions examined. Active formate-reduced FDH was crystallized under anaerobic conditions in the presence of ammonium sulfate and PEG 400. The crystals diffract to 2.6 Å resolution …

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Coordination Of Selenium To Molybdenum In Formate Dehydrogenase H From Escherichia Coli, Vadim Gladyshev, Sergei V. Khangulov, Milton J. Axley, Thressa A. Stadtman May 1994

Coordination Of Selenium To Molybdenum In Formate Dehydrogenase H From Escherichia Coli, Vadim Gladyshev, Sergei V. Khangulov, Milton J. Axley, Thressa A. Stadtman

Vadim Gladyshev Publications

Formate dehydrogenase H from Escherichia col contains multiple redox centers, which include a molybdopterin cofactor, an iron-sulfur center, and a selenocysteine residue (SeCys-140 in the polypeptide chain) that is essential for catalytic activity. Here we show that addition of formate to the native enzyme induces a signal typical of Mo(V) species. This signal is detected by electron pm etc resonance (EPR) spectroscopy. Substitution of 77Se for natural isotope abundance Se leads to transformation of this signal, indicating a direct coordination of Se with Mo. Mutant enzyme with cysteine substituted at position 140 for the selenocysteine residue has decreased catalytic activity …

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Nicotinic Acid Hydroxylase From Clostridium Barkeri: Electron Paramagnetic Resonance Studies Show That Selenium Is Coordinated With Molybdenum In The Catalytically Active Selenium-Dependent Enzymenicotinic Acid Hydroxylase From Clostridium Barkeri: Electron Paramagnetic Resonance Studies Show That Selenium Is Coordinated With Molybdenum In The Catalytically Active Selenium-Dependent Enzyme, Vadim Gladyshev, Sergei V. Khangulov, Thressa C. Stadtman Jan 1994

Nicotinic Acid Hydroxylase From Clostridium Barkeri: Electron Paramagnetic Resonance Studies Show That Selenium Is Coordinated With Molybdenum In The Catalytically Active Selenium-Dependent Enzymenicotinic Acid Hydroxylase From Clostridium Barkeri: Electron Paramagnetic Resonance Studies Show That Selenium Is Coordinated With Molybdenum In The Catalytically Active Selenium-Dependent Enzyme, Vadim Gladyshev, Sergei V. Khangulov, Thressa C. Stadtman

Vadim Gladyshev Publications

Nicotinic acid hydroxylase from Clostidum barkeri contains selenium in an unidentified form that is dissociated as a low molecular weight compound upon denaturation of the enzyme. Other cofactors of this enzyme are molybdopterin, FAD, and iron-sulfur clusters. In the current study, we show that the enzyme, as isolated, exhibits a stable Mo(V) electron paramagnetic resonance (EPR) sal ("resting" signal) and that this signal is correlated with the selenium content and nicotinate hydroxylase activity of the enzyme. Substitution of77Se for normal selenium isotope abundance results in splitting of the Mo(V) EPR signal of the native protein without affecting the iron signals …

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