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A Resourceful Race: Bacterial Scavenging of Host Sulfur Metabolism during Colonization. Infect Immun 2022; 90:e0057921. [PMID: 35315692 DOI: 10.1128/iai.00579-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Sulfur is a requirement for life. Therefore, both the host and colonizing bacteria must regulate sulfur metabolism in a coordinated fashion to meet cellular demands. The host environment is a rich source of organic and inorganic sulfur metabolites that are utilized in critical physiological processes such as redox homeostasis and cellular signaling. As such, modulating enzymes dedicated to sulfur metabolite biosynthesis plays a vital role in host fitness. This is exemplified from a molecular standpoint through layered regulation of this machinery at the transcriptional, translational, and posttranslational levels. With such a diverse metabolite pool available, pathogens and symbionts have evolved multiple mechanisms to exploit sulfur reservoirs to ensure propagation within the host. Indeed, characterization of sulfur transporters has revealed that bacteria employ multiple tactics to acquire ideal sulfur sources, such as cysteine and its derivatives. However, bacteria that employ acquisition strategies targeting multiple sulfur sources complicate in vivo studies that investigate how specific sulfur metabolites support proliferation. Furthermore, regulatory systems controlling the bacterial sulfur regulon are also multifaceted. This too creates an interesting challenge for in vivo work focused on bacterial regulation of sulfur metabolism in response to the host. This review examines the importance of sulfur at the host-bacterium interface and the elegant studies conducted to define this interaction.
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Murugan M, Fedele D, Millner D, Alharfoush E, Vegunta G, Boison D. Adenosine kinase: An epigenetic modulator in development and disease. Neurochem Int 2021; 147:105054. [PMID: 33961946 DOI: 10.1016/j.neuint.2021.105054] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 04/20/2021] [Accepted: 04/24/2021] [Indexed: 02/06/2023]
Abstract
Adenosine kinase (ADK) is the key regulator of adenosine and catalyzes the metabolism of adenosine to 5'-adenosine monophosphate. The enzyme exists in two isoforms: a long isoform (ADK-long, ADK-L) and a short isoform (ADK-short, ADK-S). The two isoforms are developmentally regulated and are differentially expressed in distinct subcellular compartments with ADK-L localized in the nucleus and ADK-S localized in the cytoplasm. The nuclear localization of ADK-L and its biochemical link to the transmethylation pathway suggest a specific role for gene regulation via epigenetic mechanisms. Recent evidence reveals an adenosine receptor-independent role of ADK in determining the global methylation status of DNA and thereby contributing to epigenomic regulation. Here we summarize recent progress in understanding the biochemical interactions between adenosine metabolism by ADK-L and epigenetic modifications linked to transmethylation reactions. This review will provide a comprehensive overview of ADK-associated changes in DNA methylation in developmental, as well as in pathological conditions including brain injury, epilepsy, vascular diseases, cancer, and diabetes. Challenges in investigating the epigenetic role of ADK for therapeutic gains are briefly discussed.
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Affiliation(s)
- Madhuvika Murugan
- Department of Neurosurgery, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ 08854, USA
| | - Denise Fedele
- Department of Neurosurgery, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ 08854, USA
| | - David Millner
- Department of Neurosurgery, New Jersey Medical School, Rutgers University, Newark, NJ 07102, USA
| | - Enmar Alharfoush
- Department of Cell Biology and Neuroscience, Rutgers University, New Brunswick, NJ 08901, USA
| | - Geetasravya Vegunta
- Department of Biology, Albert Dorman Honors College, New Jersey Institute of Technology, Newark, NJ, 07102, USA
| | - Detlev Boison
- Department of Neurosurgery, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ 08854, USA; Department of Neurosurgery, New Jersey Medical School, Rutgers University, Newark, NJ 07102, USA; Brain Health Institute, Rutgers University, Piscataway, NJ 08854, USA.
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Greco CM, Cervantes M, Fustin JM, Ito K, Ceglia N, Samad M, Shi J, Koronowski KB, Forne I, Ranjit S, Gaucher J, Kinouchi K, Kojima R, Gratton E, Li W, Baldi P, Imhof A, Okamura H, Sassone-Corsi P. S-adenosyl-l-homocysteine hydrolase links methionine metabolism to the circadian clock and chromatin remodeling. SCIENCE ADVANCES 2020; 6:eabc5629. [PMID: 33328229 PMCID: PMC7744083 DOI: 10.1126/sciadv.abc5629] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 10/30/2020] [Indexed: 05/03/2023]
Abstract
Circadian gene expression driven by transcription activators CLOCK and BMAL1 is intimately associated with dynamic chromatin remodeling. However, how cellular metabolism directs circadian chromatin remodeling is virtually unexplored. We report that the S-adenosylhomocysteine (SAH) hydrolyzing enzyme adenosylhomocysteinase (AHCY) cyclically associates to CLOCK-BMAL1 at chromatin sites and promotes circadian transcriptional activity. SAH is a potent feedback inhibitor of S-adenosylmethionine (SAM)-dependent methyltransferases, and timely hydrolysis of SAH by AHCY is critical to sustain methylation reactions. We show that AHCY is essential for cyclic H3K4 trimethylation, genome-wide recruitment of BMAL1 to chromatin, and subsequent circadian transcription. Depletion or targeted pharmacological inhibition of AHCY in mammalian cells markedly decreases the amplitude of circadian gene expression. In mice, pharmacological inhibition of AHCY in the hypothalamus alters circadian locomotor activity and rhythmic transcription within the suprachiasmatic nucleus. These results reveal a previously unappreciated connection between cellular metabolism, chromatin dynamics, and circadian regulation.
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Affiliation(s)
- Carolina Magdalen Greco
- Center for Epigenetics and Metabolism; U1233 INSERM; Department of Biological Chemistry, School of Medicine, University of California, Irvine (UCI), Irvine, CA, USA.
| | - Marlene Cervantes
- Center for Epigenetics and Metabolism; U1233 INSERM; Department of Biological Chemistry, School of Medicine, University of California, Irvine (UCI), Irvine, CA, USA
| | - Jean-Michel Fustin
- Graduate School of Pharmaceutical Sciences, Department of Systems Biology, Kyoto University, Kyoto 606-8501, Japan
| | - Kakeru Ito
- Graduate School of Pharmaceutical Sciences, Department of Systems Biology, Kyoto University, Kyoto 606-8501, Japan
| | - Nicholas Ceglia
- Institute for Genomics and Bioinformatics, School of Information and Computer Sciences, University of California Irvine (UCI), Irvine, CA, USA
| | - Muntaha Samad
- Institute for Genomics and Bioinformatics, School of Information and Computer Sciences, University of California Irvine (UCI), Irvine, CA, USA
| | - Jiejun Shi
- Department of Biological Chemistry, School of Medicine, University of California Irvine (UCI), Irvine, CA, USA
- Division of Biostatistics, Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, TX, USA
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Kevin Brian Koronowski
- Center for Epigenetics and Metabolism; U1233 INSERM; Department of Biological Chemistry, School of Medicine, University of California, Irvine (UCI), Irvine, CA, USA
| | - Ignasi Forne
- Biomedical Center, Protein Analysis Unit, Faculty of Medicine, Ludwig-Maximilians-Universität München, Großhaderner Strasse 9, 82152 Planegg-Martinsried, Germany
| | - Suman Ranjit
- Laboratory for Fluorescence Dynamics, Department of Biomedical Engineering, University of California Irvine (UCI), Irvine, CA, USA
| | - Jonathan Gaucher
- Center for Epigenetics and Metabolism; U1233 INSERM; Department of Biological Chemistry, School of Medicine, University of California, Irvine (UCI), Irvine, CA, USA
| | - Kenichiro Kinouchi
- Center for Epigenetics and Metabolism; U1233 INSERM; Department of Biological Chemistry, School of Medicine, University of California, Irvine (UCI), Irvine, CA, USA
| | - Rika Kojima
- Graduate School of Pharmaceutical Sciences, Department of Systems Biology, Kyoto University, Kyoto 606-8501, Japan
| | - Enrico Gratton
- Laboratory for Fluorescence Dynamics, Department of Biomedical Engineering, University of California Irvine (UCI), Irvine, CA, USA
| | - Wei Li
- Department of Biological Chemistry, School of Medicine, University of California Irvine (UCI), Irvine, CA, USA
- Division of Biostatistics, Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, TX, USA
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Pierre Baldi
- Institute for Genomics and Bioinformatics, School of Information and Computer Sciences, University of California Irvine (UCI), Irvine, CA, USA
| | - Axel Imhof
- Biomedical Center, Protein Analysis Unit, Faculty of Medicine, Ludwig-Maximilians-Universität München, Großhaderner Strasse 9, 82152 Planegg-Martinsried, Germany
| | - Hitoshi Okamura
- Graduate School of Pharmaceutical Sciences, Department of Systems Biology, Kyoto University, Kyoto 606-8501, Japan
| | - Paolo Sassone-Corsi
- Center for Epigenetics and Metabolism; U1233 INSERM; Department of Biological Chemistry, School of Medicine, University of California, Irvine (UCI), Irvine, CA, USA.
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Grbeša I, Kalo A, Belužić R, Kovačević L, Lepur A, Rokić F, Hochberg H, Kanter I, Simunović V, Muńoz-Torres PM, Shav-Tal Y, Vugrek O. Mutations in S-adenosylhomocysteine hydrolase (AHCY) affect its nucleocytoplasmic distribution and capability to interact with S-adenosylhomocysteine hydrolase-like 1 protein. Eur J Cell Biol 2017. [PMID: 28647132 DOI: 10.1016/j.ejcb.2017.05.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
S-adenosylhomocysteine hydrolase (AHCY) is thought to be located at the sites of ongoing AdoMet-dependent methylation, presumably in the cell nucleus. Endogenous AHCY is located both in cytoplasm and the nucleus. Little is known regarding mechanisms that drive its subcellular distribution, and even less is known on how mutations causing AHCY deficiency affect its intracellular dynamics. Using fluorescence microscopy and GFP-tagged AHCY constructs we show significant differences in the intensity ratio between nuclei and cytoplasm for mutant proteins when compared with wild type AHCY. Interestingly, nuclear export of AHCY is not affected by leptomycin B. Systematic deletions showed that AHCY has two regions, located at both sides of the protein, that contribute to its nuclear localization, implying the interaction with various proteins. In order to evaluate protein interactions in vivo we engaged in bimolecular fluorescence complementation (BiFC) based studies. We investigated previously assumed interaction with AHCY-like-1 protein (AHCYL1), a paralog of AHCY. Indeed, significant interaction between both proteins exists. Additionally, silencing AHCYL1 leads to moderate inhibition of nuclear export of endogenous AHCY.
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Affiliation(s)
- Ivana Grbeša
- Laboratory for Advanced Genomics, Department of Molecular Medicine, Ruđer Bošković Institute, 10000 Zagreb, Croatia; The Mina & Everard Goodman Faculty of Life Sciences and Institute of Nanotechnology, Bar-Ilan University, Ramat Gan 52900, Israel
| | - Alon Kalo
- The Mina & Everard Goodman Faculty of Life Sciences and Institute of Nanotechnology, Bar-Ilan University, Ramat Gan 52900, Israel
| | - Robert Belužić
- Laboratory for Advanced Genomics, Department of Molecular Medicine, Ruđer Bošković Institute, 10000 Zagreb, Croatia
| | - Lucija Kovačević
- Laboratory for Advanced Genomics, Department of Molecular Medicine, Ruđer Bošković Institute, 10000 Zagreb, Croatia
| | - Adriana Lepur
- Laboratory for Advanced Genomics, Department of Molecular Medicine, Ruđer Bošković Institute, 10000 Zagreb, Croatia
| | - Filip Rokić
- Laboratory for Advanced Genomics, Department of Molecular Medicine, Ruđer Bošković Institute, 10000 Zagreb, Croatia
| | - Hodaya Hochberg
- The Mina & Everard Goodman Faculty of Life Sciences and Institute of Nanotechnology, Bar-Ilan University, Ramat Gan 52900, Israel
| | - Itamar Kanter
- The Mina & Everard Goodman Faculty of Life Sciences and Institute of Nanotechnology, Bar-Ilan University, Ramat Gan 52900, Israel
| | - Vesna Simunović
- Laboratory for Advanced Genomics, Department of Molecular Medicine, Ruđer Bošković Institute, 10000 Zagreb, Croatia
| | - Pau Marc Muńoz-Torres
- Laboratory for Advanced Genomics, Department of Molecular Medicine, Ruđer Bošković Institute, 10000 Zagreb, Croatia
| | - Yaron Shav-Tal
- The Mina & Everard Goodman Faculty of Life Sciences and Institute of Nanotechnology, Bar-Ilan University, Ramat Gan 52900, Israel
| | - Oliver Vugrek
- Laboratory for Advanced Genomics, Department of Molecular Medicine, Ruđer Bošković Institute, 10000 Zagreb, Croatia.
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Borth H, Weber N, Meyer D, Wartenberg A, Arlt E, Zierler S, Breit A, Wennemuth G, Gudermann T, Boekhoff I. The IP3 R Binding Protein Released With Inositol 1,4,5-Trisphosphate Is Expressed in Rodent Reproductive Tissue and Spermatozoa. J Cell Physiol 2015; 231:1114-29. [PMID: 26439876 DOI: 10.1002/jcp.25209] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Accepted: 09/30/2015] [Indexed: 11/08/2022]
Abstract
Besides its capacity to inhibit the 1,4,5-trisphosphate (IP3) receptor, the regulatory protein IRBIT (IP3 receptor binding protein released with IP3) is also able to control the activity of numerous ion channels and electrolyte transporters and thereby creates an optimal electrolyte composition of various biological fluids. Since a reliable execution of spermatogenesis and sperm maturation critically depends on the establishment of an adequate microenvironment, the expression of IRBIT in male reproductive tissue was examined using immunohistochemical approaches combined with biochemical fractionation methods. The present study documents that IRBIT is expressed in Leydig and Sertoli cells. In addition, pronounced IRBIT expression was detected in sperm precursors during early stages of spermatogenesis as well as in spermatozoa. Analyzing tissue sections of rodent epididymides, IRBIT was found to co-localize with the proton pumping V-ATPase and the cystic fibrosis transmembrane conductance regulator (CFTR) at the apical surface of narrow and clear cells. A similar co-localization of IRBIT with CFTR was also observed for Sertoli cells and developing germ cells. Remarkably, assaying caudal sperm in immunogold electron microscopy, IRBIT was found to localize to the acrosomal cap and the flagellum as well as to the sperm nucleus; moreover, a prominent oligomerization was observed for spermatozoa. The pronounced occurrence of IRBIT in the male reproductive system and mature spermatozoa indicates a potential role for IRBIT in establishing the essential luminal environment for a faithful execution of spermatogenesis and epididymal sperm maturation, and suggest a participation of IRBIT during maturation steps after ejaculation and/or the final fertilization process.
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Affiliation(s)
- Heike Borth
- Walther Straub Institute of Pharmacology and Toxicology, Ludwig-Maximilians-Universit, ä, t M, ü, nchen, München, Germany
| | - Nele Weber
- Walther Straub Institute of Pharmacology and Toxicology, Ludwig-Maximilians-Universit, ä, t M, ü, nchen, München, Germany
| | - Dorke Meyer
- Walther Straub Institute of Pharmacology and Toxicology, Ludwig-Maximilians-Universit, ä, t M, ü, nchen, München, Germany
| | - Andrea Wartenberg
- Walther Straub Institute of Pharmacology and Toxicology, Ludwig-Maximilians-Universit, ä, t M, ü, nchen, München, Germany
| | - Elisabeth Arlt
- Walther Straub Institute of Pharmacology and Toxicology, Ludwig-Maximilians-Universit, ä, t M, ü, nchen, München, Germany
| | - Susanna Zierler
- Walther Straub Institute of Pharmacology and Toxicology, Ludwig-Maximilians-Universit, ä, t M, ü, nchen, München, Germany
| | - Andreas Breit
- Walther Straub Institute of Pharmacology and Toxicology, Ludwig-Maximilians-Universit, ä, t M, ü, nchen, München, Germany
| | - Gunther Wennemuth
- Department of Anatomy, University Clinic Essen, University of Duisburg-Essen, Germany
| | - Thomas Gudermann
- Walther Straub Institute of Pharmacology and Toxicology, Ludwig-Maximilians-Universit, ä, t M, ü, nchen, München, Germany
| | - Ingrid Boekhoff
- Walther Straub Institute of Pharmacology and Toxicology, Ludwig-Maximilians-Universit, ä, t M, ü, nchen, München, Germany
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Barroso M, Florindo C, Kalwa H, Silva Z, Turanov AA, Carlson BA, de Almeida IT, Blom HJ, Gladyshev VN, Hatfield DL, Michel T, Castro R, Loscalzo J, Handy DE. Inhibition of cellular methyltransferases promotes endothelial cell activation by suppressing glutathione peroxidase 1 protein expression. J Biol Chem 2014; 289:15350-62. [PMID: 24719327 PMCID: PMC4140892 DOI: 10.1074/jbc.m114.549782] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
S-adenosylhomocysteine (SAH) is a negative regulator of most methyltransferases and the precursor for the cardiovascular risk factor homocysteine. We have previously identified a link between the homocysteine-induced suppression of the selenoprotein glutathione peroxidase 1 (GPx-1) and endothelial dysfunction. Here we demonstrate a specific mechanism by which hypomethylation, promoted by the accumulation of the homocysteine precursor SAH, suppresses GPx-1 expression and leads to inflammatory activation of endothelial cells. The expression of GPx-1 and a subset of other selenoproteins is dependent on the methylation of the tRNA(Sec) to the Um34 form. The formation of methylated tRNA(Sec) facilitates translational incorporation of selenocysteine at a UGA codon. Our findings demonstrate that SAH accumulation in endothelial cells suppresses the expression of GPx-1 to promote oxidative stress. Hypomethylation stress, caused by SAH accumulation, inhibits the formation of the methylated isoform of the tRNA(Sec) and reduces GPx-1 expression. In contrast, under these conditions, the expression and activity of thioredoxin reductase 1, another selenoprotein, is increased. Furthermore, SAH-induced oxidative stress creates a proinflammatory activation of endothelial cells characterized by up-regulation of adhesion molecules and an augmented capacity to bind leukocytes. Taken together, these data suggest that SAH accumulation in endothelial cells can induce tRNA(Sec) hypomethylation, which alters the expression of selenoproteins such as GPx-1 to contribute to a proatherogenic endothelial phenotype.
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Affiliation(s)
- Madalena Barroso
- From the Cardiovascular and ,the Research Institute for Medicines and Pharmaceutical Sciences (iMed.UL) and
| | - Cristina Florindo
- the Research Institute for Medicines and Pharmaceutical Sciences (iMed.UL) and
| | | | - Zélia Silva
- the Chronic Diseases Research Center, Departamento de Imunologia, Faculdade de Ciências Médicas, Universidade Nova de Lisboa, 1099-085 Lisbon, Portugal
| | - Anton A. Turanov
- Genetics Divisions, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115
| | - Bradley A. Carlson
- the Molecular Biology of Selenium Section, Mouse Cancer Genetics Program, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, and
| | - Isabel Tavares de Almeida
- the Research Institute for Medicines and Pharmaceutical Sciences (iMed.UL) and ,Department of Biochemistry and Human Biology, Faculty of Pharmacy, University of Lisbon, 1649-004 Lisbon, Portugal
| | - Henk J. Blom
- the Department of General Pediatrics, Center for Pediatrics and Adolescent Medicine, University Hospital, 79106 Freiburg, Germany
| | - Vadim N. Gladyshev
- Genetics Divisions, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115
| | - Dolph L. Hatfield
- the Molecular Biology of Selenium Section, Mouse Cancer Genetics Program, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, and
| | | | - Rita Castro
- the Research Institute for Medicines and Pharmaceutical Sciences (iMed.UL) and ,Department of Biochemistry and Human Biology, Faculty of Pharmacy, University of Lisbon, 1649-004 Lisbon, Portugal
| | | | - Diane E. Handy
- From the Cardiovascular and , To whom correspondence should be addressed: Cardiovascular Div., Dept. of Medicine, Brigham and Women's Hospital and Harvard Medical School, 77 Ave. Louis Pasteur, Boston, MA, 02115. Tel.: 617-525-4845; Fax: 617-525-4830; E-mail:
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Wu X, Sun J, Zhang X, Li X, Liu Z, Yang Q, Li L. Epigenetic Signature of Chronic Cerebral Hypoperfusion and Beneficial Effects of S-adenosylmethionine in Rats. Mol Neurobiol 2014; 50:839-51. [DOI: 10.1007/s12035-014-8698-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2013] [Accepted: 03/24/2014] [Indexed: 11/27/2022]
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Tehlivets O, Malanovic N, Visram M, Pavkov-Keller T, Keller W. S-adenosyl-L-homocysteine hydrolase and methylation disorders: yeast as a model system. Biochim Biophys Acta Mol Basis Dis 2012; 1832:204-15. [PMID: 23017368 PMCID: PMC3787734 DOI: 10.1016/j.bbadis.2012.09.007] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2012] [Revised: 09/14/2012] [Accepted: 09/18/2012] [Indexed: 12/14/2022]
Abstract
S-adenosyl-L-methionine (AdoMet)-dependent methylation is central to the regulation of many biological processes: more than 50 AdoMet-dependent methyltransferases methylate a broad spectrum of cellular compounds including nucleic acids, proteins and lipids. Common to all AdoMet-dependent methyltransferase reactions is the release of the strong product inhibitor S-adenosyl-L-homocysteine (AdoHcy), as a by-product of the reaction. S-adenosyl-L-homocysteine hydrolase is the only eukaryotic enzyme capable of reversible AdoHcy hydrolysis to adenosine and homocysteine and, thus, relief from AdoHcy inhibition. Impaired S-adenosyl-L-homocysteine hydrolase activity in humans results in AdoHcy accumulation and severe pathological consequences. Hyperhomocysteinemia, which is characterized by elevated levels of homocysteine in blood, also exhibits a similar phenotype of AdoHcy accumulation due to the reversal of the direction of the S-adenosyl-L-homocysteine hydrolase reaction. Inhibition of S-adenosyl-L-homocysteine hydrolase is also linked to antiviral effects. In this review the advantages of yeast as an experimental system to understand pathologies associated with AdoHcy accumulation will be discussed.
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Affiliation(s)
- Oksana Tehlivets
- Institute of Molecular Biosciences, University of Graz, Graz, Austria.
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Characterization, expression and localization of S-adenosylhomocysteine hydrolase from amphioxus Branchiostoma belcheri tsingtaunese. Biosci Rep 2009; 28:135-44. [PMID: 18532926 DOI: 10.1042/bsr20080024] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
A cDNA clone encoding AmphiSAHH [amphioxus SAHH (S-adenosylhomocysteine hydrolase)] protein was isolated from a cDNA library from the gut of Branchiostoma belcheri tsingtaunese. It contained a 1305 bp open reading frame corresponding to a deduced protein of 434 amino acid residues, with a predicted molecular mass of approx. 47.8 kDa. Phylogenetic analysis showed that AmphiSAHH and sea-urchin SAHH joined together and positioned at the base of the vertebrate SAHH clade, suggesting that both AmphiSAHH and sea-urchin SAHH might share some characteristics of the archetype of vertebrate SAHH proteins. The genomic DNA sequence of AmphiSAHH contained eight exons and seven introns, which was similar to B. floridae and sea-urchin SAHH exon/intron organization. Sequence comparison suggested the evolutionary appearance of the ten exon/nine intron organization of SAHH genes after the split of invertebrates and vertebrates, after which it has been highly conserved. AmphiSAHH has been successfully expressed in Escherichia coli and purified. Western blotting confirmed that the enzyme has a native molecular mass of approx. 48 kDa, and the catalytic activities and NAD(+)/NADH binding affinity of recombinant AmphiSAHH were measured. Immunohistochemistry analysis showed that SAHH was strongly expressed in hepatic caecum, gill, spermary and ovary of amphioxus.
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10
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Cui XA, Singh B, Park J, Gupta RS. Subcellular localization of adenosine kinase in mammalian cells: The long isoform of AdK is localized in the nucleus. Biochem Biophys Res Commun 2009; 388:46-50. [PMID: 19635462 DOI: 10.1016/j.bbrc.2009.07.106] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2009] [Accepted: 07/22/2009] [Indexed: 12/25/2022]
Abstract
Two isoforms of adenosine kinase (AdK) have been identified in mammalian organisms with the long isoform (AdK-long) containing extra 20-21 amino acids at the N-terminus (NTS). The subcellular localizations of these isoforms are not known and they contain no identifiable targeting sequence. Immunofluorescence labeling of mammalian cells expressing either only AdK-long or both isoforms with AdK-specific antibody showed only nuclear labeling or both nucleus and cytoplasmic labeling, respectively. The AdK-long and -short isoforms fused at the C-terminus with c-myc epitope also localized in the nucleus and cytoplasm, respectively. Fusion of the AdK-long NTS to green fluorescent protein also resulted in its nuclear localization. AdK-long NTS contains a cluster of conserved amino acids (PKPKKLKVE). Replacement of KK in this sequence with either AA or AD abolished its nuclear localization capability, indicating that this cluster likely serves as a nuclear localization signal. AdK in nucleus is likely required for sustaining methylation reactions.
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Affiliation(s)
- Xianying Amy Cui
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ont., Canada
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11
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Bera S, Wallimann T, Ray S, Ray M. Enzymes of creatine biosynthesis, arginine and methionine metabolism in normal and malignant cells. FEBS J 2009; 275:5899-909. [PMID: 19021765 DOI: 10.1111/j.1742-4658.2008.06718.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
The creatine/creatine kinase system decreases drastically in sarcoma. In the present study, an investigation of catalytic activities, western blot and mRNA expression unambiguously demonstrates the prominent expression of the creatine-synthesizing enzymes l-arginine:glycine amidinotransferase and N-guanidinoacetate methyltransferase in sarcoma, Ehrlich ascites carcinoma and Sarcoma 180 cells, whereas both enzymes were virtually undetectable in normal muscle. Compared to that of normal animals, these enzymes remained unaffected in the kidney or liver of sarcoma-bearing mice. High activity and expression of mitochondrial arginase II in sarcoma indicated increased ornithine formation. Slightly or moderately higher levels of ornithine, guanidinoacetate and creatinine were observed in sarcoma compared to muscle. Despite the intrinsically low level of creatine in Ehrlich ascites carcinoma and Sarcoma 180 cells, these cells could significantly take up and release creatine, suggesting a functional creatine transport, as verified by measuring mRNA levels of creatine transporter. Transcript levels of arginase II, ornithine-decarboxylase, S-adenosyl-homocysteine hydrolase and methionine-synthase were significantly upregulated in sarcoma and in Ehrlich ascites carcinoma and Sarcoma 180 cells. Overall, the enzymes related to creatine and arginine/methionine metabolism were found to be significantly upregulated in malignant cells. However, the low levels of creatine kinase in the same malignant cells do not appear to be sufficient for the building up of an effective creatine/phosphocreatine pool. Instead of supporting creatine biosynthesis, l-arginine:glycine amidinotransferase and N-guanidinoacetate methyltransferase appear to be geared to support cancer cell metabolism in the direction of polyamine and methionine synthesis because both these compounds are in high demand in proliferating cancer cells.
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Affiliation(s)
- Soumen Bera
- Department of Biological Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata, India
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12
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Grenz A, Zhang H, Weingart J, von Wietersheim S, Eckle T, Schnermann J, Köhle C, Kloor D, Gleiter CH, Vallon V, Eltzschig HK, Osswald H. Lack of effect of extracellular adenosine generation and signaling on renal erythropoietin secretion during hypoxia. Am J Physiol Renal Physiol 2007; 293:F1501-11. [PMID: 17855480 DOI: 10.1152/ajprenal.00243.2007] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Previous studies have yielded conflicting results as to whether extracellular adenosine generation and signaling contributes to hypoxia-induced increases in renal erythropoietin (EPO) secretion. In this study, we combined pharmacological and genetic approaches to elucidate a potential contribution of extracellular adenosine to renal EPO release in mice. To stimulate EPO secretion, we used murine carbon monoxide exposure (400 and 750 parts per million CO, 4 h), ambient hypoxia (8% oxygen, 4 h), or arterial hemodilution. Because the ecto-5-nucleotidase (CD73, conversion of AMP to adenosine) is considered the pacemaker of extracellular adenosine generation, we first tested the effect of blocking extracellular adenosine generation with the specific CD73-inhibitor adenosine 5'-(alpha,beta-methylene) diphosphate (APCP) or by gene-targeted deletion of cd73. These studies showed that neither APCP-treatment nor targeted deletion of cd73 resulted in changes of stimulated EPO mRNA or serum levels, although the increases of adenosine levels in the kidney following CO exposure were attenuated in mice with APCP treatment or in cd73(-/-) mice. Moreover, pharmacological studies using specific inhibitors of individual adenosine receptors (A1 AR, DPCPX; A 2A AR, DMPX; A 2B AR, PSB 1115; A3AR, MRS 1191) showed no effect on stimulated increases of EPO mRNA or serum levels. Finally, stimulated EPO secretion was not attenuated in gene-targeted mice lacking A1A(-/-, A2A AR-/-, A2BAR(-/-), or A3AR-/-. Together, these studies combine genetic and pharmacological in vivo evidence that increases of EPO secretion during limited oxygen availability are not affected by extracellular adenosine generation or signaling.
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Affiliation(s)
- Almut Grenz
- Dept. of Pharmacology and Toxicology, Tübingen Univ. Hospital, Wilhelmstr. 56, D-72074 Tübingen, Germany
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