Open Access. Powered by Scholars. Published by Universities.®

Biochemistry, Biophysics, and Structural Biology Commons™

Open Access. Powered by Scholars. Published by Universities.®

Vadim Gladyshev Publications

Articles 61 - 90 of 110

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

Mammalian And Other Eukaryotic Selenocysteine Trnas, Bradley A. Carlson, Xue-Ming Xu, Rajeev Shrimali, Aniruddha Sengupta, Min-Hyuk Yoo, Robert Irons, Nianxin Zhong, Dolph L. Hatfield, Byeong Jae Lee, Alexei V. Lobanov, Vadim N. Gladyshev Jun 2006

Mammalian And Other Eukaryotic Selenocysteine Trnas, Bradley A. Carlson, Xue-Ming Xu, Rajeev Shrimali, Aniruddha Sengupta, Min-Hyuk Yoo, Robert Irons, Nianxin Zhong, Dolph L. Hatfield, Byeong Jae Lee, Alexei V. Lobanov, Vadim N. Gladyshev

Vadim Gladyshev Publications

Selenocysteine (Sec) tRNA occupies a prominent position in the expression of selenoproteins as it is essential for their synthesis and it provides the means by which selenium is co-translationally inserted into protein as the amino acid, Sec. Thus, Sec tRNA is regarded as the principle constituent in selenoprotein synthesis. Many features unique to this tRNA have been characterized over the years in mammals and other eukaryotes. In the last five years, the major advances have been in an elucidation of the different roles that the two major Sec tRNA isoforms play in selenoprotein biosynthesis and in Sec biosynthesis. One isoform …

Go to article

Thioredoxin Reductase 1 Deficiency Reverses Tumor Phenotype And Tumorigenicity Of Lung Carcinoma Cells, Min-Hyuk Yoo, Xue-Ming Xu, Bradley A. Carlson, Vadim N. Gladyshev, Dolph L. Hatfield May 2006

Thioredoxin Reductase 1 Deficiency Reverses Tumor Phenotype And Tumorigenicity Of Lung Carcinoma Cells, Min-Hyuk Yoo, Xue-Ming Xu, Bradley A. Carlson, Vadim N. Gladyshev, Dolph L. Hatfield

Vadim Gladyshev Publications

Dietary selenium has potent cancer prevention activity. Both low molecular weight selenocompounds and selenoproteins are implicated in this effect. Thioredoxin reductase 1 (TR1) is one of the major antioxidant and redox regulators in mammals that supports p53 function and other tumor suppressor activities. However, this selenium-containing oxidoreductase is also overexpressed in many malignant cells and has been proposed as a target for cancer therapy. To further assess the role of TR1 in the malignancy process, we used RNA interference technology to decrease its expression in mouse lung carcinoma (LLC1) cells. Stable transfection of LLC1 cells with a small interfering RNA …

Go to article

Alternative First Exon Splicing Regulates Subcellular Distribution Of Methionine Sulfoxide Reductases, Hwa-Young Kim, Vadim Gladyshev Mar 2006

Alternative First Exon Splicing Regulates Subcellular Distribution Of Methionine Sulfoxide Reductases, Hwa-Young Kim, Vadim Gladyshev

Vadim Gladyshev Publications

Background: Methionine sulfoxide reduction is an important protein repair pathway that protects against oxidative stress, controls protein function and has a role in regulation of aging. There are two enzymes that reduce stereospecifically oxidized methionine residues: MsrA (methionine-Ssulfoxide reductase) and MsrB (methionine-R-sulfoxide reductase). In many organisms, these enzymes are targeted to various cellular compartments. In mammals, a single MsrA gene is known, however, its product is present in cytosol, nucleus, and mitochondria. In contrast, three mammalian MsrB genes have been identified whose products are located in different cellular compartments.
Results: In the present study, we identified and characterized alternatively spliced …

Go to article

Identification And Characterization Of Fep15, A New Selenocysteine-Containing Member Of The Sep15 Protein Family, Sergey V. Novoselov, Deame Hua, A. V. Lobanov, Vadim N. Gladyshev Mar 2006

Identification And Characterization Of Fep15, A New Selenocysteine-Containing Member Of The Sep15 Protein Family, Sergey V. Novoselov, Deame Hua, A. V. Lobanov, Vadim N. Gladyshev

Vadim Gladyshev Publications

Sec (selenocysteine) is a rare amino acid in proteins. It is co-translationally inserted into proteins at UGA codons with the help of SECIS (Sec insertion sequence) elements. A full set of selenoproteins within a genome, known as the selenoproteome, is highly variable in different organisms. However, most of the known eukaryotic selenoproteins are represented in the mammalian selenoproteome. In addition, many of these selenoproteins have cysteine orthologues. Here, we describe a new selenoprotein, designated Fep15, which is distantly related to members of the 15 kDa selenoprotein (Sep15) family. Fep15 is absent in mammals, can be detected only in fi sh …

Go to article

Nmr Structures Of The Selenoproteins Sep15 And Selm Reveal Redox Activity Of A New Thioredoxin-Like Family, Andrew D. Ferguson, Vyacheslav Labunskyy, Dmitri E. Fomenko, Demet Arac, Yogarany Chelliah, Carlos A. Amexcua, Josep Rizo, Vadim N. Gladyshev, Johann Deisenhofer Feb 2006

Nmr Structures Of The Selenoproteins Sep15 And Selm Reveal Redox Activity Of A New Thioredoxin-Like Family, Andrew D. Ferguson, Vyacheslav Labunskyy, Dmitri E. Fomenko, Demet Arac, Yogarany Chelliah, Carlos A. Amexcua, Josep Rizo, Vadim N. Gladyshev, Johann Deisenhofer

Vadim Gladyshev Publications

Selenium has significant health benefits, including potent cancer prevention activity and roles in immune function and the male reproductive system. Selenium-containing proteins, which incorporate this essential micronutrient as selenocysteine, are proposed to mediate the positive effects of dietary selenium. Presented here are the solution NMR structures of the selenoprotein SelM and an ortholog of the selenoprotein Sep15. These data reveal that Sep15 and SelM are structural homologs that establish a new thioredoxinlike protein family. The location of the active-site redox motifs within the fold together with the observed localized conformational changes after thiol-disulfide exchange and measured redox potential indicate that …

Go to article

The Plasmodium Selenoproteome, Alexey V. Lobanov, Cesar Delgado, Stefan Rahlfs, Sergey V. Novoselov, Gregory V. Kryukov, Stephan Gromer, Dolph L. Hatfield, Katja Becker, Vadim Gladyshev Jan 2006

The Plasmodium Selenoproteome, Alexey V. Lobanov, Cesar Delgado, Stefan Rahlfs, Sergey V. Novoselov, Gregory V. Kryukov, Stephan Gromer, Dolph L. Hatfield, Katja Becker, Vadim Gladyshev

Vadim Gladyshev Publications

The use of selenocysteine (Sec) as the 21st amino acid in the genetic code has been described in all three major domains of life. However, within eukaryotes, selenoproteins are only known in animals and algae. In this study, we characterized selenoproteomes and Sec insertion systems in protozoan Apicomplexa parasites. We found that among these organisms, Plasmodium and Toxoplasma utilized Sec, whereas Cryptosporidium did not. However, Plasmodium had no homologs of known selenoproteins. By searching computationally for evolutionarily conserved selenocysteine insertion sequence (SECIS) elements, which are RNA structures involved in Sec insertion, we identified four unique Plasmodium falciparum selenoprotein genes. These …

Go to article

Evidence For Direct Roles Of Two Additional Factors, Secp43 And Soluble Liver Antigen, In The Selenoprotein Synthesis Machinery, Xue-Ming Xu, Heiko Mix, Bradley A. Carlson, Paula J. Grabowski, Vadim N. Gladyshev, Marla J. Berry, Dolph L. Hatfield Dec 2005

Evidence For Direct Roles Of Two Additional Factors, Secp43 And Soluble Liver Antigen, In The Selenoprotein Synthesis Machinery, Xue-Ming Xu, Heiko Mix, Bradley A. Carlson, Paula J. Grabowski, Vadim N. Gladyshev, Marla J. Berry, Dolph L. Hatfield

Vadim Gladyshev Publications

Selenocysteine (Sec) is inserted into selenoproteins co-translationally with the help of various cis- and trans-acting factors. The specific mechanisms of Sec biosynthesis and insertion into protein in eukaryotic cells, however, are not known. Two proteins, SECp43 and the soluble liver antigen (SLA), were previously reported to interact with tRNA [Ser]Sec, but their functions remained elusive. Herein, we report that knockdown of SECp43 in NIH3T3 or TCMK-1 cells using RNA interference technology resulted in a reduction in the level of methylation at the 2’-hydroxylribosyl moiety in the wobble position (Um34) of Sec tRNA [Ser]Sec, and consequently reduced glutathione peroxidase …

Go to article

Different Catalytic Mechanisms In Mammalian Selenocysteine- And Cysteine-Containing Methionine-R-Sulfoxide Reductases, Hwa-Young Kim, Vadim Gladyshev Dec 2005

Different Catalytic Mechanisms In Mammalian Selenocysteine- And Cysteine-Containing Methionine-R-Sulfoxide Reductases, Hwa-Young Kim, Vadim Gladyshev

Vadim Gladyshev Publications

Selenocysteine (Sec) is found in active sites of several oxidoreductases in which this residue is essential for catalytic activity. However, many selenoproteins have fully functional orthologs, wherein cysteine (Cys) occupies the position of Sec. The reason why some enzymes evolve into selenoproteins if the Cys versions may be sufficient is not understood. Among three mammalian methionine-R-sulfoxide reductases (MsrBs), MsrB1 is a Sec-containing protein, whereas MsrB2 and MsrB3 contain Cys in the active site, making these enzymes an excellent system for addressing the question of why Sec is used in biological systems. In this study, we found that residues, which are …

Go to article

A Novel Cysteine-Rich Domain Of Sep15 Mediates The Interaction With Udp-Glucose:Glycoprotein Glucosyltransferase, Vyacheslav M. Labunskyy, Andrew D. Ferguson, Dmitri E. Fomenko, Yogarany Chelliah, Dolph L. Hatfield, Vadim N. Gladyshev Nov 2005

A Novel Cysteine-Rich Domain Of Sep15 Mediates The Interaction With Udp-Glucose:Glycoprotein Glucosyltransferase, Vyacheslav M. Labunskyy, Andrew D. Ferguson, Dmitri E. Fomenko, Yogarany Chelliah, Dolph L. Hatfield, Vadim N. Gladyshev

Vadim Gladyshev Publications

Selenium is an essential trace element with potent cancer prevention activity in mammals. The 15-kDa selenoprotein (Sep15) has been implicated in the chemopreventive effect of dietary selenium. Although the precise function of Sep15 remains elusive, Sep15 copurifies with UDP-glucose:glycoprotein glucosyltransferase (GT), an essential regulator of quality control mechanisms within the endoplasmic reticulum. Recent studies identified two GT and two Sep15 homologues in mammals. We characterize interactions between these protein families in this report. Sep15 and GT form a tight 1:1 complex, and these interactions are conserved between mammals and fruit flies. In mammalian cells, Sep15 co-immunoprecipitates with both GT isozymes. …

Go to article

Crystal Structures Of Oxidized And Reduced Mitochondrial Thioredoxin Reductase Provide Molecular Details Of The Reaction Mechanism, Ekaterina I. Biterova, Anton A. Turanov, Vadim N. Gladyshev, Joseph J. Barycki Oct 2005

Crystal Structures Of Oxidized And Reduced Mitochondrial Thioredoxin Reductase Provide Molecular Details Of The Reaction Mechanism, Ekaterina I. Biterova, Anton A. Turanov, Vadim N. Gladyshev, Joseph J. Barycki

Vadim Gladyshev Publications

Thioredoxin reductase (TrxR) is an essential enzyme required for the efficient maintenance of the cellular redox homeostasis, particularly in cancer cells that are sensitive to reactive oxygen species. In mammals, distinct isozymes function in the cytosol and mitochondria. Through an intricate mechanism, these enzymes transfer reducing equivalents from NADPH to bound FAD and subsequently to an active-site disulfide. In mammalian TrxRs, the dithiol then reduces a mobile C-terminal selenocysteine- containing tetrapeptide of the opposing subunit of the dimer. Once activated, the C-terminal redox center reduces a disulfide bond within thioredoxin. In this report, we present the structural data on a …

Go to article

Evolution Of Selenium Utilization Traits, Hector Romero, Yan Zhang, Vadim Gladyshev, Gustavo Salinas Jul 2005

Evolution Of Selenium Utilization Traits, Hector Romero, Yan Zhang, Vadim Gladyshev, Gustavo Salinas

Vadim Gladyshev Publications

Background: The essential trace element selenium is used in a wide variety of biological processes. Selenocysteine (Sec), the 21st amino acid, is co-translationally incorporated into a restricted set of proteins. It is encoded by an UGA codon with the help of tRNASec (SelC), Sec-specific elongation factor (SelB) and a cis-acting mRNA structure (SECIS element). In addition, Sec synthase (SelA) and selenophosphate synthetase (SelD) are involved in the biosynthesis of Sec on the tRNASec. Selenium is also found in the form of 2-selenouridine, a modified base present in the wobble position of certain tRNAs, whose synthesis is …

Go to article

Mammalian Selenoprotein Thioredoxin-Glutathione Reductase, Dan Su, Sergey V. Novoselov, Qi-An Sun, Mohamed E. Moustafa, You Zhou, Richard Oko, Dolph L. Hatfield, Vadim N. Gladyshev Jul 2005

Mammalian Selenoprotein Thioredoxin-Glutathione Reductase, Dan Su, Sergey V. Novoselov, Qi-An Sun, Mohamed E. Moustafa, You Zhou, Richard Oko, Dolph L. Hatfield, Vadim N. Gladyshev

Vadim Gladyshev Publications

Thioredoxin reductases (TRs) are important redox regulatory enzymes, which control the redox state of thioredoxins. Mammals have cytosolic and mitochondrial TRs, which contain an essential selenocysteine residue and reduce cytosolic and mitochondrial thioredoxins. In addition, thioredoxin/glutathione reductase (TGR) was identified, which is a fusion of an N-terminal glutaredoxin domain and the TR module. Here we show that TGR is expressed at low levels in various tissues but accumulates in testes after puberty. The protein is particularly abundant in elongating spermatids at the site of mitochondrial sheath formation but is absent in mature sperm. We found that TGR can catalyze isomerization …

Go to article

Pyrrolysine And Selenocysteine Use Dissimilar Decoding Strategies, Yan Zhang, Pavel V. Baranov, John F. Atkins, Vadim N. Gladyshev May 2005

Pyrrolysine And Selenocysteine Use Dissimilar Decoding Strategies, Yan Zhang, Pavel V. Baranov, John F. Atkins, Vadim N. Gladyshev

Vadim Gladyshev Publications

Selenocysteine (Sec) and pyrrolysine (Pyl) are known as the 21st and 22nd amino acids in protein. Both are encoded by codons that normally function as stop signals. Sec specification by UGA codons requires the presence of a cis-acting selenocysteine insertion sequence (SECIS) element. Similarly, it is thought that Pyl is inserted by UAG codons with the help of a putative pyrrolysine insertion sequence (PYLIS) element. Herein, we analyzed the occurrence of Pyl-utilizing organisms, Pyl-associated genes, and Pyl-containing proteins. The Pyl trait is restricted to several microbes, and only one organism has both Pyl and Sec. We found that methanogenic …

Go to article

Selenocysteine Insertion Directed By The 3’-Utr Secis Element In Escherichia Coli, Dan Su, Yehua Li, Vadim Gladyshev Apr 2005

Selenocysteine Insertion Directed By The 3’-Utr Secis Element In Escherichia Coli, Dan Su, Yehua Li, Vadim Gladyshev

Vadim Gladyshev Publications

Co-translational insertion of selenocysteine (Sec) into proteins in response to UGA codons is directed by selenocysteine insertion sequence (SECIS) elements. In known bacterial selenoprotein genes, SECIS elements are located in the coding regions immediately downstream of UGA codons. Here, we report that a distant SECIS element can also function in Sec insertion in bacteria provided that it is spatially close to the UGA codon. We expressed a mammalian phospholipid hydroperoxide glutathione peroxidase in Escherichia coli from a construct in which a natural E.coli SECIS element was located in the 3’-untranslated region (3’-UTR) and adjacent to a sequence complementary to the …

Go to article

Nematode Selenoproteome: The Use Of The Selenocysteine Insertion System To Decode One Codon In An Animal Genome?, Kalin Taskov, Charles Chapple, Gregory V. Kryukov, Sergi Castenello, Alexei V. Lobanov, Konstantin V. Korotkov, Roderic Guigo, Vadim Gladyshev Apr 2005

Nematode Selenoproteome: The Use Of The Selenocysteine Insertion System To Decode One Codon In An Animal Genome?, Kalin Taskov, Charles Chapple, Gregory V. Kryukov, Sergi Castenello, Alexei V. Lobanov, Konstantin V. Korotkov, Roderic Guigo, Vadim Gladyshev

Vadim Gladyshev Publications

Selenocysteine (Sec) is co-translationally inserted into selenoproteins in response to codon UGA with the help of the selenocysteine insertion sequence (SECIS) element.The number of selenoproteinsinanimals varies, with humans having 25 and mice having 24 selenoproteins. To date, however, only one selenoprotein, thioredoxin reductase, has been detected in Caenorhabditis elegans, and this enzyme contains only one Sec. Here, we characterize the selenoproteomes of C.elegans and Caenorhabditis briggsae with three independent algorithms,one searching for pairs of homologous nematode SECIS elements, another searching for Cys- or Sec-containing homologs of potential nematode selenoprotein genes and the third identifying Sec-containing homologs of annotated nematode …

Go to article

The Microbial Selenoproteome Of The Sargasso Sea, Yan Zhang, Dmitri E. Fomenko, Vadim Gladyshev Mar 2005

The Microbial Selenoproteome Of The Sargasso Sea, Yan Zhang, Dmitri E. Fomenko, Vadim Gladyshev

Vadim Gladyshev Publications

Background: Selenocysteine (Sec) is a rare amino acid which occurs in proteins in major domains of life. It is encoded by TGA, which also serves as the signal for termination of translation, precluding identification of selenoprotein genes by available annotation tools. Information on full sets of selenoproteins (selenoproteomes) is essential for understanding the biology of selenium. Herein, we characterized the selenoproteome of the largest microbial sequence dataset, the Sargasso Sea environmental genome project.
Results: We identified 310 selenoprotein genes that clustered into 25 families, including 101 new selenoprotein genes that belonged to 15 families. Most of these proteins were predicted …

Go to article

Um34 In Selenocysteine Trna Is Required For The Expression Of Stress-Related Selenoproteins In Mammals, Bradley A. Carlson, Xue-Ming Xu, Vadim N. Gladyshev, Dolph L. Hatfield Mar 2005

Um34 In Selenocysteine Trna Is Required For The Expression Of Stress-Related Selenoproteins In Mammals, Bradley A. Carlson, Xue-Ming Xu, Vadim N. Gladyshev, Dolph L. Hatfield

Vadim Gladyshev Publications

Selenium is an essential micronutrient in the diet of mammals and has many health benefits. Selenium-containing proteins are responsible for most, if not all, of these benefits. This element is incorporated into protein as selenocysteine (Sec), the 21st amino acid in the genetic code. There are two species of Sec tRNA in mammalian cells that differ by a single 2’-O-hydroxymethyl group on the ribosyl moiety at position 34 (Um34). The relationship between this modification and selenoprotein synthesis was examined in mice in which the wild type Sec tRNA gene was replaced with a mutant Sec tRNA transgene incapable of …

Go to article

Selective Rescue Of Selenoprotein Expression In Mice Lacking A Highly Specialized Methyl Group In Selenocysteine Trna, Bradley A. Carlson, Xue-Ming Xu, Vadim N. Gladyshev, Dolph L. Hatfield Feb 2005

Selective Rescue Of Selenoprotein Expression In Mice Lacking A Highly Specialized Methyl Group In Selenocysteine Trna, Bradley A. Carlson, Xue-Ming Xu, Vadim N. Gladyshev, Dolph L. Hatfield

Vadim Gladyshev Publications

Selenocysteine (Sec) is the 21st amino acid in the genetic code. Its tRNA is variably methylated on the 2’-Ohydroxyl site of the ribosyl moiety at position 34 (Um34). Herein, we identified a role of Um34 in regulating the expression of some, but not all, selenoproteins. A strain of knock-out transgenic mice was generated, wherein the Sec tRNA gene was replaced with either wild type or mutant Sec tRNA transgenes. The mutant transgene yielded a tRNA that lacked two base modifications, N6- isopentenyladenosine at position 37 (i6A37) and Um34. Several selenoproteins, including glutathione peroxidases 1 and 3, …

Go to article

Identification And Characterization Of Phosphoseryl-Trna [Ser]Sec Kinase, Bradley A. Carlson, Xue-Ming Xu, Gregory V. Kryukov, Mahadev Rao, Marla J. Berry, Vadim N. Gladyshev, Dolph L. Hatfield Aug 2004

Identification And Characterization Of Phosphoseryl-Trna [Ser]Sec Kinase, Bradley A. Carlson, Xue-Ming Xu, Gregory V. Kryukov, Mahadev Rao, Marla J. Berry, Vadim N. Gladyshev, Dolph L. Hatfield

Vadim Gladyshev Publications

In 1970, a kinase activity that phosphorylated a minor species of seryl-tRNA to form phosphoseryl-tRNA was found in rooster liver [Maenpaa, P. H. & Bernfield, M. R. (1970) Proc. Natl. Acad. Sci. USA 67, 688–695], and a minor seryl-tRNA that decoded the nonsense UGA was detected in bovine liver. The phosphoseryl-tRNA and the minor UGA-decoding seryl-tRNA were subsequently identified as selenocysteine (Sec) tRNA [Ser]Sec, but the kinase activity remained elusive. Herein, by using a comparative genomics approach that searched completely sequenced archaeal genomes for a kinase-like protein with a pattern of occurrence similar to that of components of Sec …

Go to article

The Prokaryotic Selenoproteome, Gregory V. Kryukov, Vadim N. Gladyshev May 2004

The Prokaryotic Selenoproteome, Gregory V. Kryukov, Vadim N. Gladyshev

Vadim Gladyshev Publications

In the genetic code, the UGA codon has a dual function as it encodes selenocysteine (Sec) and serves as a stop signal. However, only the translation terminator function is used in gene annotation programs, resulting in misannotation of selenoprotein genes. Here, we applied two independent bioinformatics approaches to characterize a selenoprotein set in prokaryotic genomes. One method searched for selenoprotein genes by identifying RNA stem–loop structures, selenocysteine insertion sequence elements; the second approach identified Sec/Cys pairs in homologous sequences. These analyses identified all or almost all selenoproteins in completely sequenced bacterial and archaeal genomes and provided a view on the …

Go to article

Specific Excision Of The Selenocysteine Trna [Ser]Sec (Trsp) Gene In Mouse Liver Demonstrates An Essential Role Of Selenoproteins In Liver Function, Bradley A. Carlson, Sergey V. Novoselov, Easwari Kumaraswamy, Byeong Jae Lee, Miriam R. Anver, Vadim N. Gladyshev, Dolph L. Hatfield Feb 2004

Specific Excision Of The Selenocysteine Trna [Ser]Sec (Trsp) Gene In Mouse Liver Demonstrates An Essential Role Of Selenoproteins In Liver Function, Bradley A. Carlson, Sergey V. Novoselov, Easwari Kumaraswamy, Byeong Jae Lee, Miriam R. Anver, Vadim N. Gladyshev, Dolph L. Hatfield

Vadim Gladyshev Publications

Selenium is essential in mammalian embryonic development. However, in adults, selenoprotein levels in several organs including liver can be substantially reduced by selenium deficiency without any apparent change in phenotype. To address the role of selenoproteins in liver function, mice homozygous for a floxed allele encoding the selenocysteine (Sec) tRNA [Ser]Sec gene were crossed with transgenic mice carrying the Cre recombinase under the control of the albumin promoter that expresses the recombinase specifically in liver. Recombination was nearly complete in mice 3 weeks of age, whereas liver selenoprotein synthesis was virtually absent, which correlated with the loss of Sec tRNA …

Go to article

Methionine Sulfoxide Reduction In Mammals: Characterization Of Methionine-R-Sulfoxide Reductases, Hwa-Young Kim, Vadim Gladyshev Feb 2004

Methionine Sulfoxide Reduction In Mammals: Characterization Of Methionine-R-Sulfoxide Reductases, Hwa-Young Kim, Vadim Gladyshev

Vadim Gladyshev Publications

Methionine residues in proteins are susceptible to oxidation by reactive oxygen species, but can be repaired via reduction of the resulting methionine sulfoxides by methionine-S-sulfoxide reductase (MsrA) and methionine-R-sulfoxide reductase (MsrB). However, the identity of all methionine sulfoxide reductases involved, their cellular locations and relative contributions to the overall pathway are poorly understood. Here, we describe a methionine-R-sulfoxide reduction system in mammals, in which two MsrB homologues were previously described. We found that human and mouse genomes possess three MsrB genes and characterized their protein products, designated MsrB1, MsrB2, and MsrB3. MsrB1 (Selenoprotein R) was present in the cytosol and …

Go to article

Identification Of Trace Element-Containing Proteins In Genomic Databases, Vadim N. Gladyshev, Gregory V. Kryukov, Dmitri E. Fomenko, Dolph L. Hatfield Jan 2004

Identification Of Trace Element-Containing Proteins In Genomic Databases, Vadim N. Gladyshev, Gregory V. Kryukov, Dmitri E. Fomenko, Dolph L. Hatfield

Vadim Gladyshev Publications

Development of bioinformatics tools provided researchers with the ability to identify full sets of trace element–containing proteins in organisms for which complete genomic sequences are available. Recently, independent bioinformatics methods were used to identify all, or almost all, genes encoding selenocysteine-containing proteins in human, mouse, and Drosophila genomes, characterizing entire selenoproteomes in these organisms. It also should be possible to search for entire sets of other trace element–associated proteins, such as metal-containing proteins, although methods for their identification are still in development.

Go to article

Reconsidering The Evolution Of Eukaryotic Selenoproteins: A Novel Nonmammalian Family With Scattered Phylogenetic Distribution, Sergi Castellano, Sergey V. Novoselov, Gregory V. Kryukov, Alain Lescure, Enrique Blanco, Alain Krol, Vadim N. Gladyshev, Roderic Guigo Jan 2004

Reconsidering The Evolution Of Eukaryotic Selenoproteins: A Novel Nonmammalian Family With Scattered Phylogenetic Distribution, Sergi Castellano, Sergey V. Novoselov, Gregory V. Kryukov, Alain Lescure, Enrique Blanco, Alain Krol, Vadim N. Gladyshev, Roderic Guigo

Vadim Gladyshev Publications

While the genome sequence and gene content are available for an increasing number of organisms, eukaryotic selenoproteins remain poorly characterized. The dual role of the UGA codon confounds the identification of novel selenoprotein genes. Here, we describe a comparative genomics approach that relies on the genome-wide prediction of genes with in-frame TGA codons, and the subsequent comparison of predictions from different genomes, wherein conservation in regions flanking the TGA codon suggests selenocysteine coding function. Application of this method to human and fugu genomes identified a novel selenoprotein family, named SelU, in the puffer fish. The selenocysteinecontaining form also occurred in …

Go to article

Reconsidering The Evolution Of Eukaryotic Selenoproteins: A Novel Nonmammalian Family With Scattered Phylogenetic Distribution, Sergi Castellano, Sergey V. Novoselov, Gregory V. Kryukov, Alain Lescure, Enrique Blanco, Alain Krol, Vadim N. Gladyshev, Roderic Guigo Jan 2004

Reconsidering The Evolution Of Eukaryotic Selenoproteins: A Novel Nonmammalian Family With Scattered Phylogenetic Distribution, Sergi Castellano, Sergey V. Novoselov, Gregory V. Kryukov, Alain Lescure, Enrique Blanco, Alain Krol, Vadim N. Gladyshev, Roderic Guigo

Vadim Gladyshev Publications

While the genome sequence and gene content are available for an increasing number of organisms, eukaryotic selenoproteins remain poorly characterized. The dual role of the UGA codon confounds the identification of novel selenoprotein genes. Here, we describe a comparative genomics approach that relies on the genome-wide prediction of genes with in-frame TGA codons, and the subsequent comparison of predictions from different genomes, wherein conservation in regions flanking the TGA codon suggests selenocysteine coding function. Application of this method to human and fugu genomes identified a novel selenoprotein family, named SelU, in the puffer fish. The selenocysteinecontaining form also occurred in …

Go to article

The Drosophila Selenoprotein Bthd Is Required For Survival And Has A Role In Salivary Gland Development, So Yeon Kwon, Paul Badenhorst, F. Javier Martin-Romero, Bradley A. Carlson, Bruce M. Paterson, Vadim Gladyshev, Byeong Jae Lee, Dolph L. Hatfield Dec 2003

The Drosophila Selenoprotein Bthd Is Required For Survival And Has A Role In Salivary Gland Development, So Yeon Kwon, Paul Badenhorst, F. Javier Martin-Romero, Bradley A. Carlson, Bruce M. Paterson, Vadim Gladyshev, Byeong Jae Lee, Dolph L. Hatfield

Vadim Gladyshev Publications

Selenium is implicated in many diseases, including cancer, but its function at the molecular level is poorly understood. BthD is one of three selenoproteins recently identified in Drosophila. To elucidate the function of BthD and the role of selenoproteins in cellular metabolism and health, we analyzed the developmental expression profile of this protein and used inducible RNA interference (RNAi) to ablate function. We find that BthD is dynamically expressed during Drosophila development. bthD mRNA and protein are abundant in the ovaries of female flies and are deposited into the developing oocyte. Maternally contributed protein and RNA persist during early …

Go to article

Chlamydomonas Reinhardtii Selenocysteine Trna [Ser]Sec, Mahadev Rao, Bradley A. Carlson, Sergey V. Novoselov, Donald P. Weeks, Vadim Gladyshev, Dolph L. Hatfield Jul 2003

Chlamydomonas Reinhardtii Selenocysteine Trna [Ser]Sec, Mahadev Rao, Bradley A. Carlson, Sergey V. Novoselov, Donald P. Weeks, Vadim Gladyshev, Dolph L. Hatfield

Vadim Gladyshev Publications

Eukaryotic selenocysteine (Sec) protein insertion machinery was thought to be restricted to animals, but the occurrence of both Sec-containing proteins and the Sec insertion system was recently found in Chlamydomonas reinhardtii, a member of the plant kingdom. Herein, we used RT-PCR to determine the sequence of C. reinhardtii Sec tRNA [Ser]Sec, the first non-animal eukaryotic Sec tRNA [Ser]Sec sequence. Like its animal counterpart, it is 90 nucleotides in length, is aminoacylated with serine by seryl-tRNA synthetase, and decodes specifically UGA. Evolutionary analyses of known Sec tRNAs identify the C. reinhardtii form as the most diverged eukaryotic Sec tRNA …

Go to article

Characterization Of Mammalian Selenoproteomes, Gregory V. Kryukov, Sergi Castellano, Sergey V. Novoselov, Alexey V. Lobanov, Omid Zehtab, Roderic Guigo, Vadim N. Gladyshev May 2003

Characterization Of Mammalian Selenoproteomes, Gregory V. Kryukov, Sergi Castellano, Sergey V. Novoselov, Alexey V. Lobanov, Omid Zehtab, Roderic Guigo, Vadim N. Gladyshev

Vadim Gladyshev Publications

In the genetic code, UGA serves as a stop signal and a selenocysteine codon, but no computational methods for identifying its coding function are available. Consequently, most selenoprotein genes are misannotated. We identified selenoprotein genes in sequenced mammalian genomes by methods that rely on identification of selenocysteine insertion RNA structures, the coding potential of UGA codons, and the presence of cysteine-containing homologs. The human selenoproteome consists of 25 selenoproteins.

Go to article

Selective Removal Of The Selenocysteine Trna [Ser]Sec Gene (Trsp) In Mouse Mammary Epithelium, Easwari Kumaraswamy, Bradley A. Carlson, Fanta Morgan, Keiko Miyoshi, Gertraud W. Robinson, Dan Su, Shulin Wang, Eileen Southon, Lino Tessarollo, Byeong Jae Lee, Vadim Gladyshev, Lothar Hennighausen, Dolph L. Hatfield Mar 2003

Selective Removal Of The Selenocysteine Trna [Ser]Sec Gene (Trsp) In Mouse Mammary Epithelium, Easwari Kumaraswamy, Bradley A. Carlson, Fanta Morgan, Keiko Miyoshi, Gertraud W. Robinson, Dan Su, Shulin Wang, Eileen Southon, Lino Tessarollo, Byeong Jae Lee, Vadim Gladyshev, Lothar Hennighausen, Dolph L. Hatfield

Vadim Gladyshev Publications

Mice homozygous for an allele encoding the selenocysteine (Sec) tRNA [Ser]Sec gene (Trsp) flanked by loxP sites were generated. Cre recombinase-dependent removal of Trsp in these mice was lethal to embryos. To investigate the role of Trsp in mouse mammary epithelium, we deleted this gene by using transgenic mice carrying the Cre recombinase gene under control of the mouse mammary tumor virus (MMTV) long terminal repeat or the whey acidic protein promoter. While both promoters target Cre gene expression to mammary epithelium, MMTV-Cre is also expressed in spleen and skin. Sec tRNA [Ser]Sec amounts were reduced by …

Go to article

Reaction Mechanism, Evolutionary Analysis, And Role Of Zinc In Drosophila Methionine-R-Sulfoxide Reductase, R. Abhilash Kumar, Ahmet Koc, Ronald Cerny, Vadim N. Gladyshev Oct 2002

Reaction Mechanism, Evolutionary Analysis, And Role Of Zinc In Drosophila Methionine-R-Sulfoxide Reductase, R. Abhilash Kumar, Ahmet Koc, Ronald Cerny, Vadim N. Gladyshev

Vadim Gladyshev Publications

Methionine residues in proteins are susceptible to oxidation, and the resulting methionine sulfoxides can be reduced back to methionines by methionine- S-sulfoxide reductase (MsrA) and methionine-R-sulfoxide reductase (MsrB). Herein, we have identified two MsrB families that differ by the presence of zinc. Evolutionary analyses suggested that the zinc-containing MsrB proteins are prototype enzymes and that the metal was lost in certain MsrB proteins later in evolution. Zinc-containing Drosophila MsrB was further characterized. The enzyme was found to employ a catalytic Cys124 thiolate, which directly interacted with methionine sulfoxide, resulting in methionine and a Cys124 sulfenic …

Go to article

First Prev Next Last