1
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Daly O, Mahiny AJ, Majeski S, McClintock K, Reichert J, Boros G, Szabó GT, Reinholz J, Schreiner P, Reid S, Lam K, Lepper M, Adler M, Meffen T, Heyes J, Karikó K, Lutwyche P, Vlatkovic I. ASL mRNA-LNP Therapeutic for the Treatment of Argininosuccinic Aciduria Enables Survival Benefit in a Mouse Model. Biomedicines 2023; 11:1735. [PMID: 37371829 DOI: 10.3390/biomedicines11061735] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 06/05/2023] [Accepted: 06/11/2023] [Indexed: 06/29/2023] Open
Abstract
Argininosuccinic aciduria (ASA) is a metabolic disorder caused by a deficiency in argininosuccinate lyase (ASL), which cleaves argininosuccinic acid to arginine and fumarate in the urea cycle. ASL deficiency (ASLD) leads to hepatocyte dysfunction, hyperammonemia, encephalopathy, and respiratory alkalosis. Here we describe a novel therapeutic approach for treating ASA, based on nucleoside-modified messenger RNA (modRNA) formulated in lipid nanoparticles (LNP). To optimize ASL-encoding mRNA, we modified its cap, 5' and 3' untranslated regions, coding sequence, and the poly(A) tail. We tested multiple optimizations of the formulated mRNA in human cells and wild-type C57BL/6 mice. The ASL protein showed robust expression in vitro and in vivo and a favorable safety profile, with low cytokine and chemokine secretion even upon administration of increasing doses of ASL mRNA-LNP. In the ASLNeo/Neo mouse model of ASLD, intravenous administration of the lead therapeutic candidate LNP-ASL CDS2 drastically improved the survival of the mice. When administered twice a week lower doses partially protected and 3 mg/kg LNP-ASL CDS2 fully protected the mice. These results demonstrate the considerable potential of LNP-formulated, modified ASL-encoding mRNA as an effective alternative to AAV-based approaches for the treatment of ASA.
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Affiliation(s)
- Owen Daly
- Genevant Sciences Corporation, Vancouver, BC V5T 4T5, Canada
| | | | - Sara Majeski
- Genevant Sciences Corporation, Vancouver, BC V5T 4T5, Canada
| | | | | | - Gábor Boros
- BioNTech SE, An der Goldgrube 12, 55131 Mainz, Germany
| | | | | | - Petra Schreiner
- Genevant Sciences Corporation, Vancouver, BC V5T 4T5, Canada
| | - Steve Reid
- Genevant Sciences Corporation, Vancouver, BC V5T 4T5, Canada
| | - Kieu Lam
- Genevant Sciences Corporation, Vancouver, BC V5T 4T5, Canada
| | - Marlen Lepper
- BioNTech SE, An der Goldgrube 12, 55131 Mainz, Germany
| | - Melanie Adler
- BioNTech SE, An der Goldgrube 12, 55131 Mainz, Germany
| | - Tracy Meffen
- Genevant Sciences Corporation, Vancouver, BC V5T 4T5, Canada
| | - James Heyes
- Genevant Sciences Corporation, Vancouver, BC V5T 4T5, Canada
| | | | - Pete Lutwyche
- Genevant Sciences Corporation, Vancouver, BC V5T 4T5, Canada
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2
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Leuger L, Dieu X, Chao de la Barca JM, Moriconi M, Halley G, Donin de Rosière X, Reynier P, Mirebeau‐Prunier D, Homedan C. Late-onset argininosuccinic aciduria in a 72-year-old man presenting with fatal hyperammonemia. JIMD Rep 2021; 62:44-48. [PMID: 34765397 PMCID: PMC8574183 DOI: 10.1002/jmd2.12251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 09/06/2021] [Accepted: 09/08/2021] [Indexed: 11/07/2022] Open
Abstract
Argininosuccinate lyase deficiency (ASLD, MIM #207900) is an inherited urea cycle disorder. There are mainly two clinical forms, an acute neonatal form which manifests as life-threatening hyperammonemia, and a late-onset form characterised by polymorphic neuro-cognitive or psychiatric presentation with transient hyperammonemia episodes. Here, we report a late-onset case of ASLD in a 72-year-old man carrying a homozygous pathogenic variant in the exon 16 of the ASL gene, presenting for the first time with fatal hyperammonemic coma. This case report shows the need to systematically carry out an ammonia assay when faced with an unexplained coma.
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Affiliation(s)
- Laurent Leuger
- Laboratoire de Biochimie et biologie moléculaire, Centre Hospitalier Universitaire d'AngersAngers Cedex 9France
| | - Xavier Dieu
- Laboratoire de Biochimie et biologie moléculaire, Centre Hospitalier Universitaire d'AngersAngers Cedex 9France
| | | | - Mikael Moriconi
- Service de Réanimation Polyvalente et Unité de soins continus, Centre Hospitalier de CornouailleQuimper CedexFrance
| | - Guillaume Halley
- Service de Réanimation Polyvalente et Unité de soins continus, Centre Hospitalier de CornouailleQuimper CedexFrance
| | | | - Pascal Reynier
- Laboratoire de Biochimie et biologie moléculaire, Centre Hospitalier Universitaire d'AngersAngers Cedex 9France
| | - Delphine Mirebeau‐Prunier
- Laboratoire de Biochimie et biologie moléculaire, Centre Hospitalier Universitaire d'AngersAngers Cedex 9France
| | - Chadi Homedan
- Laboratoire de Biochimie et biologie moléculaire, Centre Hospitalier Universitaire d'AngersAngers Cedex 9France
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3
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Osawa Y, Wada A, Ohtsu Y, Yamada K, Takizawa T. Late-onset argininosuccinic aciduria associated with hyperammonemia triggered by influenza infection in an adolescent: A case report. Mol Genet Metab Rep 2020; 24:100605. [PMID: 32435591 PMCID: PMC7232106 DOI: 10.1016/j.ymgmr.2020.100605] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2020] [Revised: 05/05/2020] [Indexed: 12/24/2022] Open
Abstract
Hyperammonemia is a typical symptom of urea cycle disorders. While early-onset argininosuccinic aciduria (ASA) can often be detected by hyperammonemia, patients with late-onset ASA predominantly present with psychomotor retardation and mental disorders. However, in late-onset ASA that develops during early childhood, hyperammonemia can sometimes be caused by acute infections, stress, and reduced dietary intake. Here, we report the case of a 14-year-old boy with late-onset ASA associated with hyperammonemia that was triggered by an influenza A infection. Due to the infection, he presented with a fever and was unable to eat food or take oral medication. He then experienced restlessness, a disturbance in his level of consciousness, and seizures. Hyperammonemia (3286 μg/dL, reference value ≤100 μg/dL) was detected. He was biochemically diagnosed with ASA based on increased serum and urinary argininosuccinic acid levels. Additionally, genetic testing revealed compound heterozygous mutations in the ASL gene: c.91G > A(p.Asp31Asn) and c.1251-1G > C. This case revealed that in late-onset ASA, hyperammonemia can occur not only in early childhood but also during adolescence. Late-onset ASA may have a very broad clinical spectrum that includes hyperammonemia. We suggest that urea cycle disorders such as ASA must be considered when patients present with hyperammonemic decompensation during adolescence.
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Affiliation(s)
- Yoshimitsu Osawa
- Department of Pediatrics, Gunma University Graduate School of Medicine, Japan.,Department of Pediatrics, Shimane University Faculty of Medicine, Japan
| | - Aya Wada
- Department of Pediatrics, Gunma University Graduate School of Medicine, Japan
| | - Yoshiaki Ohtsu
- Department of Pediatrics, Gunma University Graduate School of Medicine, Japan
| | - Kenji Yamada
- Department of Pediatrics, Shimane University Faculty of Medicine, Japan
| | - Takumi Takizawa
- Department of Pediatrics, Gunma University Graduate School of Medicine, Japan
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4
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Diez-Fernandez C, Hertig D, Loup M, Diserens G, Henry H, Vermathen P, Nuoffer JM, Häberle J, Braissant O. Argininosuccinate neurotoxicity and prevention by creatine in argininosuccinate lyase deficiency: An in vitro study in rat three-dimensional organotypic brain cell cultures. J Inherit Metab Dis 2019; 42:1077-1087. [PMID: 30907007 DOI: 10.1002/jimd.12090] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2018] [Revised: 03/04/2019] [Accepted: 03/22/2019] [Indexed: 12/31/2022]
Abstract
The urea cycle disorder (UCD) argininosuccinate lyase (ASL) deficiency, caused by a defective ASL enzyme, exhibits a wide range of phenotypes, from life-threatening neonatal hyperammonemia to asymptomatic patients, with only the biochemical marker argininosuccinic acid (ASA) elevated in body fluids. Remarkably, even without ever suffering from hyperammonemia, patients often develop severe cognitive impairment and seizures. The goal of this study was to understand the effect on the known toxic metabolite ASA and the assumed toxic metabolite guanidinosuccinic acid (GSA) on developing brain cells, and to evaluate the potential role of creatine (Cr) supplementation, as it was described protective for brain cells exposed to ammonia. We used an in vitro model, in which we exposed three-dimensional (3D) organotypic rat brain cell cultures in aggregates to different combinations of the metabolites of interest at two time points (representing two different developmental stages). After harvest and cryopreservation of the cell cultures, the samples were analyzed mainly by metabolite analysis, immunohistochemistry, and western blotting. ASA and GSA were found toxic for astrocytes and neurons. This toxicity could be reverted in vitro by Cr. As well, an antiapoptotic effect of ASA was revealed, which could contribute to the neurotoxicity in ASL deficiency. Further studies in human ASL deficiency will be required to understand the biochemical situation in the brain of affected patients, and to investigate the impact of high or low arginine doses on brain Cr availability. In addition, clinical trials to evaluate the beneficial effect of Cr supplementation in ASL deficiency would be valuable.
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Affiliation(s)
- Carmen Diez-Fernandez
- Division of Metabolism and Children's Research Center, University Children's Hospital Zurich, Zurich, Switzerland
| | - Damian Hertig
- Division of Pediatric Endocrinology, Diabetology and Metabolism and University Institute of Clinical Chemistry, Inselspital, University Hospital, University of Bern, Bern, Switzerland
- AMSM, Department of Biomedical Research, University of Bern, Bern, Switzerland
- AMSM, Department of Radiology, University of Bern, Bern, Switzerland
- Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | - Marc Loup
- Service of Clinical Chemistry, Lausanne University Hospital and University of Lausanne, Switzerland
| | - Gaelle Diserens
- AMSM, Department of Biomedical Research, University of Bern, Bern, Switzerland
- AMSM, Department of Radiology, University of Bern, Bern, Switzerland
| | - Hugues Henry
- Service of Clinical Chemistry, Lausanne University Hospital and University of Lausanne, Switzerland
| | - Peter Vermathen
- AMSM, Department of Biomedical Research, University of Bern, Bern, Switzerland
- AMSM, Department of Radiology, University of Bern, Bern, Switzerland
| | - Jean-Marc Nuoffer
- Division of Pediatric Endocrinology, Diabetology and Metabolism and University Institute of Clinical Chemistry, Inselspital, University Hospital, University of Bern, Bern, Switzerland
| | - Johannes Häberle
- Division of Metabolism and Children's Research Center, University Children's Hospital Zurich, Zurich, Switzerland
| | - Olivier Braissant
- Service of Clinical Chemistry, Lausanne University Hospital and University of Lausanne, Switzerland
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5
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Baruteau J, Diez-Fernandez C, Lerner S, Ranucci G, Gissen P, Dionisi-Vici C, Nagamani S, Erez A, Häberle J. Argininosuccinic aciduria: Recent pathophysiological insights and therapeutic prospects. J Inherit Metab Dis 2019; 42:1147-1161. [PMID: 30723942 DOI: 10.1002/jimd.12047] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2018] [Accepted: 12/20/2018] [Indexed: 12/30/2022]
Abstract
The first patients affected by argininosuccinic aciduria (ASA) were reported 60 years ago. The clinical presentation was initially described as similar to other urea cycle defects, but increasing evidence has shown overtime an atypical systemic phenotype with a paradoxical observation, that is, a higher rate of neurological complications contrasting with a lower rate of hyperammonaemic episodes. The disappointing long-term clinical outcomes of many of the patients have challenged the current standard of care and therapeutic strategy, which aims to normalize plasma ammonia and arginine levels. Interrogations have raised about the benefit of newborn screening or liver transplantation on the neurological phenotype. Over the last decade, novel discoveries enabled by the generation of new transgenic argininosuccinate lyase (ASL)-deficient mouse models have been achieved, such as, a better understanding of ASL and its close interaction with nitric oxide metabolism, ASL physiological role outside the liver, and the pathophysiological role of oxidative/nitrosative stress or excessive arginine treatment. Here, we present a collaborative review, which highlights these recent discoveries and novel emerging concepts about ASL role in human physiology, ASA clinical phenotype and geographic prevalence, limits of current standard of care and newborn screening, pathophysiology of the disease, and emerging novel therapies. We propose recommendations for monitoring of ASA patients. Ongoing research aims to better understand the underlying pathogenic mechanisms of the systemic disease to design novel therapies.
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Affiliation(s)
- Julien Baruteau
- UCL Great Ormond Street Institute of Child Health, NIHR Great Ormond Street Hospital Biomedical Research Centre, London, UK
- Metabolic Department, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Carmen Diez-Fernandez
- Division of Metabolism and Children Research Centre (CRC), University Children's Hospital, Zurich, Switzerland
| | - Shaul Lerner
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israël
| | - Giusy Ranucci
- Division of Metabolism, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Paul Gissen
- UCL Great Ormond Street Institute of Child Health, NIHR Great Ormond Street Hospital Biomedical Research Centre, London, UK
- Metabolic Department, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Carlo Dionisi-Vici
- Division of Metabolism, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Sandesh Nagamani
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
| | - Ayelet Erez
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israël
| | - Johannes Häberle
- Division of Metabolism and Children Research Centre (CRC), University Children's Hospital, Zurich, Switzerland
- Zurich Center for Integrative Human Physiology (ZIHP) and Neuroscience Center Zurich (ZNZ), Zurich, Switzerland
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6
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Ali EZ, Yakob Y, Ngu LH. Identification of mutations in Malaysian patients with argininosuccinate lyase (ASL) deficiency. Mol Genet Metab Rep 2019; 21:100525. [PMID: 31709144 PMCID: PMC6831900 DOI: 10.1016/j.ymgmr.2019.100525] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 09/16/2019] [Accepted: 09/16/2019] [Indexed: 12/30/2022] Open
Abstract
Argininosuccinate lyase (ASL) deficiency impairs the function of the urea cycle that detoxifies blood ammonia in the body. Mutation that occurs in the ASL gene is the cause of occurrence of ASL deficiency (ASLD). This deficiency causes hyperammonemia, hepatopathy and neurodevelopmental delay in patients. In this study, the clinical characteristics and molecular analysis of 10 ASLD patients were presented. 8 patients were associated with severe neonatal onset, while the other 2 were associated with late onset. Molecular analysis of ASL gene identified four new missense variants, which were c.778C>T, p.(Leu260Arg), c.1340G>C, p.(Ser447Thr), c.436C>G, p.(Arg146Gly) and c.595C>G, p.(Leu199Val) and four reported missense variants, which were c.638G>A, p.(Arg213Gln); c.556C>T, p.(Arg186Trp), c.578G>A, p.(Arg193Gln) and c.436C>G, p.(Arg146Trp). In silico servers predicted all new and reported variants as disease-causing. Structural examination exhibited that all pathogenic variants affected the stability of the tetrameric ASL structure by disturbing the bonding pattern with the neighboring residues. Conclusion This study revealed the genetic heterogeneity among Malaysian ASL patients. This study has also expanded the mutational spectrum of the ASL.
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Affiliation(s)
- Ernie Zuraida Ali
- Inborn Error of Metabolism and Genetic Unit, Nutrition, Metabolism and Cardiovascular Research Centre, Institute for Medical Research, National Institutes of Health, Ministry of Health Malaysia, Section U13 Setia Alam, 40170 Shah Alam, Selangor, Malaysia
- Corresponding authors.
| | - Yusnita Yakob
- Molecular Diagnostics and Protein Unit, Specialized Diagnostics Centre, Institute for Medical Research, National Institutes of Health, Ministry of Health Malaysia, Jalan Pahang, 50588 Kuala Lumpur, Malaysia
| | - Lock Hock Ngu
- Medical Genetics Department, Kuala Lumpur Hospital, Ministry of Health Malaysia, Jalan Pahang, 50588 Kuala Lumpur, Malaysia
- Corresponding authors.
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Whole-Exome Sequencing Identified a Novel Compound Heterozygous Genotype in ASL in a Chinese Han Patient with Argininosuccinate Lyase Deficiency. BIOMED RESEARCH INTERNATIONAL 2019; 2019:3530198. [PMID: 31183366 PMCID: PMC6515145 DOI: 10.1155/2019/3530198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/11/2018] [Revised: 01/03/2019] [Accepted: 03/07/2019] [Indexed: 11/17/2022]
Abstract
Pathogenic variants in the argininosuccinate lyase (ASL) gene have been shown to cause argininosuccinate lyase deficiency (ASLD); therefore, sequencing analysis offers advantages for prenatal testing and counseling in families afflicted with this condition. Here, we performed a genetic analysis of an ASLD patient and his family with an aim to offer available information for clinical diagnosis. The research subjects were a 23-month-old patient with a high plasma level of citrulline and his unaffected parents. Whole-exome sequencing identified potential related ASL gene mutations in this trio. Enzymatic activity was detected spectrophotometrically by a coupled assay using arginase and measuring urea production. We identified a novel nonsynonymous mutation (c.206A>G, p.Lys69Arg) and a stop mutation (c.637C>T, p.Arg213∗) in ASL in a Chinese Han patient with ASLD. The enzymatic activity of a p.Lys69Arg ASL construct in human embryonic kidney 293T cells was significantly reduced compared to that of the wild-type construct, and no significant activity was observed for the p.Arg213∗ construct. Compound heterozygous p.Lys69Arg and p.Arg213∗ mutations that resulted in reduced ASL enzyme activity were found in a patient with ASLD. This finding expands the clinical spectrum of ASL pathogenic variants.
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8
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RNA stability regulates human T cell leukemia virus type 1 gene expression in chronically-infected CD4 T cells. Virology 2017; 508:7-17. [PMID: 28478312 DOI: 10.1016/j.virol.2017.04.029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Revised: 04/25/2017] [Accepted: 04/26/2017] [Indexed: 11/22/2022]
Abstract
Regulation of expression of HTLV-1 gene products from integrated proviruses plays an important role in HTLV-1-associated disease pathogenesis. Previous studies have shown that T cell receptor (TCR)- and phorbol ester (PMA) stimulation of chronically infected CD4 T cells increases the expression of integrated HTLV-1 proviruses in latently infected cells, however the mechanism remains unknown. Analysis of HTLV-1 RNA and protein species following PMA treatment of the latently HTLV-1-infected, FS and SP T cell lines demonstrated rapid induction of tax/rex mRNA. This rapid increase in tax/rex mRNA was associated with markedly enhanced tax/rex mRNA stability while the stability of unspliced or singly spliced HTLV-1 RNAs did not increase. Tax/rex mRNA in the HTLV-1 constitutively expressing cell lines exhibited high basal stability even without PMA treatment. Our data support a model whereby T cell activation leads to increased HTLV-1 gene expression at least in part through increased tax/rex mRNA stability.
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Hu L, Pandey AV, Balmer C, Eggimann S, Rüfenacht V, Nuoffer JM, Häberle J. Unstable argininosuccinate lyase in variant forms of the urea cycle disorder argininosuccinic aciduria. J Inherit Metab Dis 2015; 38:815-27. [PMID: 25778938 DOI: 10.1007/s10545-014-9807-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Revised: 12/11/2014] [Accepted: 12/19/2014] [Indexed: 12/30/2022]
Abstract
Loss of function of the urea cycle enzyme argininosuccinate lyase (ASL) is caused by mutations in the ASL gene leading to ASL deficiency (ASLD). ASLD has a broad clinical spectrum ranging from life-threatening severe neonatal to asymptomatic forms. Different levels of residual ASL activity probably contribute to the phenotypic variability but reliable expression systems allowing clinically useful conclusions are not yet available. In order to define the molecular characteristics underlying the phenotypic variability, we investigated all ASL mutations that were hitherto identified in patients with late onset or mild clinical and biochemical courses by ASL expression in human embryonic kidney 293 T cells. We found residual activities >3% of ASL wild type (WT) in nine of 11 ASL mutations. Six ASL mutations (p.Arg95Cys, p.Ile100Thr, p.Val178Met, p.Glu189Gly, p.Val335Leu, and p.Arg379Cys) with residual activities ≥16% of ASL WT showed no significant or less than twofold reduced Km values, but displayed thermal instability. Computational structural analysis supported the biochemical findings by revealing multiple effects including protein instability, disruption of ionic interactions and hydrogen bonds between residues in the monomeric form of the protein, and disruption of contacts between adjacent monomeric units in the ASL tetramer. These findings suggest that the clinical and biochemical course in variant forms of ASLD is associated with relevant residual levels of ASL activity as well as instability of mutant ASL proteins. Since about 30% of known ASLD genotypes are affected by mutations studied here, ASLD should be considered as a candidate for chaperone treatment to improve mutant protein stability.
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Affiliation(s)
- Liyan Hu
- Division of Metabolism, University Children's Hospital Zurich, Zurich, 8032, Switzerland
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10
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Balmer C, Pandey AV, Rüfenacht V, Nuoffer JM, Fang P, Wong LJ, Häberle J. Mutations and Polymorphisms in the HumanArgininosuccinate Lyase(ASL) Gene. Hum Mutat 2013; 35:27-35. [DOI: 10.1002/humu.22469] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Accepted: 10/09/2013] [Indexed: 12/30/2022]
Affiliation(s)
- Cécile Balmer
- Division of Metabolism; University Children's Hospital; Zurich Switzerland
- Children's Research Center; Zurich Switzerland
| | - Amit V. Pandey
- Pediatric Endocrinology; Departments of Pediatrics and Clinical Research; University of Bern; Bern Switzerland
| | - Véronique Rüfenacht
- Division of Metabolism; University Children's Hospital; Zurich Switzerland
- Children's Research Center; Zurich Switzerland
| | - Jean-Marc Nuoffer
- University Institute of Clinical Chemistry; University Children's Hospital; University of Bern; Bern 3010 Switzerland
| | - Ping Fang
- Department of Molecular and Human Genetics; Baylor College of Medicine; Houston Texas 77030
| | - Lee-Jun Wong
- Department of Molecular and Human Genetics; Baylor College of Medicine; Houston Texas 77030
| | - Johannes Häberle
- Division of Metabolism; University Children's Hospital; Zurich Switzerland
- Children's Research Center; Zurich Switzerland
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11
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Nagamani SCS, Lee B, Erez A. Optimizing therapy for argininosuccinic aciduria. Mol Genet Metab 2012; 107:10-4. [PMID: 22841516 PMCID: PMC3444682 DOI: 10.1016/j.ymgme.2012.07.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2012] [Revised: 07/11/2012] [Accepted: 07/11/2012] [Indexed: 11/30/2022]
Abstract
Argininosuccinic aciduria (ASA) is a urea cycle disorder with a complex phenotype. In spite of a lower risk for recurrent hyperammonemic episodes as compared to the proximal disorders of ureagenesis, subjects with ASA are at risk for long-term complications including, poor neurocognitive outcome, hepatic disease and systemic hypertension. These complications can occur in spite of current standard therapy that includes dietary modifications and arginine supplementation suggesting that the presently available therapy is suboptimal. In this article, we discuss the natural history of ASA and the recent mechanistic insights from animal studies that have shown the requirement of argininosuccinate lyase, the enzyme deficient in ASA, for systemic nitric oxide production. These findings may have therapeutic implications and may help optimize therapy in ASA.
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Affiliation(s)
- Sandesh CS Nagamani
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Brendan Lee
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Howard Hughes Medical Institute, Houston, USA
- Corresponding author: Brendan Lee, M.D., Ph.D., Investigator, Howard Hughes Medical Institute, Professor, Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030., Phone: 713-798-5443, Fax: 713-798-5168,
| | - Ayelet Erez
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
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Abstract
The urea cycle consists of six consecutive enzymatic reactions that convert waste nitrogen into urea. Deficiencies of any of these enzymes of the cycle result in urea cycle disorders (UCDs), a group of inborn errors of hepatic metabolism that often result in life-threatening hyperammonemia. Argininosuccinate lyase (ASL) catalyzes the fourth reaction in this cycle, resulting in the breakdown of argininosuccinic acid to arginine and fumarate. ASL deficiency (ASLD) is the second most common UCD, with a prevalence of ~1 in 70,000 live births. ASLD can manifest as either a severe neonatal-onset form with hyperammonemia within the first few days after birth or as a late-onset form with episodic hyperammonemia and/or long-term complications that include liver dysfunction, neurocognitive deficits, and hypertension. These long-term complications can occur in the absence of hyperammonemic episodes, implying that ASL has functions outside of its role in ureagenesis and the tissue-specific lack of ASL may be responsible for these manifestations. The biochemical diagnosis of ASLD is typically established with elevation of plasma citrulline together with elevated argininosuccinic acid in the plasma or urine. Molecular genetic testing of ASL and assay of ASL enzyme activity are helpful when the biochemical findings are equivocal. However, there is no correlation between the genotype or enzyme activity and clinical outcome. Treatment of acute metabolic decompensations with hyperammonemia involves discontinuing oral protein intake, supplementing oral intake with intravenous lipids and/or glucose, and use of intravenous arginine and nitrogen-scavenging therapy. Dietary restriction of protein and dietary supplementation with arginine are the mainstays in long-term management. Orthotopic liver transplantation (OLT) is best considered only in patients with recurrent hyperammonemia or metabolic decompensations resistant to conventional medical therapy.
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13
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Erez A, Nagamani SCS, Lee B. Argininosuccinate lyase deficiency-argininosuccinic aciduria and beyond. AMERICAN JOURNAL OF MEDICAL GENETICS PART C-SEMINARS IN MEDICAL GENETICS 2011; 157C:45-53. [PMID: 21312326 DOI: 10.1002/ajmg.c.30289] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The urea cycle consists of six consecutive enzymatic reactions that convert waste nitrogen into urea. Deficiencies of any of these enzymes of the cycle result in urea cycle disorders (UCD), a group of inborn errors of hepatic metabolism that often result in life threatening hyperammonemia. Argininosuccinate lyase (ASL) is a cytosolic enzyme which catalyzes the fourth reaction in the cycle and the first degradative step, that is, the breakdown of argininosuccinic acid to arginine and fumarate. Deficiency of ASL results in an accumulation of argininosuccinic acid in tissues, and excretion of argininosuccinic acid in urine leading to the condition argininosuccinic aciduria (ASA). ASA is an autosomal recessive disorder and is the second most common UCD. In addition to the accumulation of argininosuccinic acid, ASL deficiency results in decreased synthesis of arginine, a feature common to all UCDs except argininemia. Arginine is not only the precursor for the synthesis of urea and ornithine as part of the urea cycle but it is also the substrate for the synthesis of nitric oxide, polyamines, proline, glutamate, creatine, and agmatine. Hence, while ASL is the only enzyme in the body able to generate arginine, at least four enzymes use arginine as substrate: arginine decarboxylase, arginase, nitric oxide synthetase (NOS) and arginine/glycine aminotransferase. In the liver, the main function of ASL is ureagenesis, and hence, there is no net synthesis of arginine. In contrast, in most other tissues, its role is to generate arginine that is designated for the specific cell's needs. While patients with ASA share the acute clinical phenotype of hyperammonemia, encephalopathy, and respiratory alkalosis common to other UCD, they also present with unique chronic complications most probably caused by a combination of tissue specific deficiency of arginine and/or elevation of argininosuccinic acid. This review article summarizes the clinical characterization, biochemical, enzymatic, and molecular features of this disorder. Current treatment, prenatal diagnosis, diagnosis through the newborn screening as well as hypothesis driven future treatment modalities are discussed.
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Affiliation(s)
- Ayelet Erez
- Department of Molecular and Human, Genetics at Baylor College of Medicine, Houston, TX 77030, USA
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The interaction of Glu294 at the subunit interface is important for the activity and stability of goose delta-crystallin. Mol Vis 2009; 15:2358-63. [PMID: 19936305 PMCID: PMC2779060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2009] [Accepted: 11/01/2009] [Indexed: 12/01/2022] Open
Abstract
PURPOSE delta-Crystallin is a soluble structural protein in found in avian eye lenses; it shares high amino acid sequence identity with argininosuccinate lyase. E294 is the only residue located at the double dimer interface and it performs hydrogen bonding with the active site residues of H160 and K323 in the neighboring and diagonal subunits, respectively. H160 is reported to play an important role in catalysis due to its H-bond interaction with the fumarate moiety of the substrate. In order to clarify the function of E294 in either stabilization of the quaternary structure or in catalysis, we carried out site-directed mutagenesis and functional analysis. METHODS The structure of both wild-type and mutant proteins were analyzed by circular dichroism (CD) spectroscopy, fluorescence spectra, and analytical ultracentrifugation. Structural stability was measured by CD and tryptophan fluorescence. A modeled structure of the E294L mutant was built and optimized with energy minimization. RESULTS No gross structural changes were observed when E294 was substituted with leucine, as judged by circular dichroism, tryptophan fluorescence, ANS fluorescence, and sedimentation velocity analyses. However, this mutant enzyme had only about 10% of the activity of a wild-type enzyme and its secondary structure was more easily denatured by increased temperature than that of a wild-type enzyme. The mutant protein also underwent its first unfolding transition at a lower concentration of guanidinium-hydrochloride than the wild-type protein. CONCLUSIONS These results indicate that the interactions offered by E294 in the dimer-dimer interface of delta-crystallin are required to maintain the hydrogen bonding network in the active site for catalysis. Disruption of the interaction had no significant effect on the conformation and quaternary structure of delta-crystallin but it did lead to instability in the double dimer structure.
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Trevisson E, Burlina A, Doimo M, Pertegato V, Casarin A, Cesaro L, Navas P, Basso G, Sartori G, Salviati L. Functional complementation in yeast allows molecular characterization of missense argininosuccinate lyase mutations. J Biol Chem 2009; 284:28926-34. [PMID: 19703900 DOI: 10.1074/jbc.m109.050195] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Deficiency of argininosuccinate lyase (ASL) causes argininosuccinic aciduria, an urea cycle defect that may present with a severe neonatal onset form or with a late onset phenotype. To date phenotype-genotype correlations are still not clear because biochemical assays of ASL activity correlate poorly with clinical severity in patients. We employed a yeast-based functional complementation assay to assess the pathogenicity of 12 missense ASL mutations, to establish genotype-phenotype correlations, and to screen for intragenic complementation. Rather than determining ASL enzyme activity directly, we have measured the growth rate in arginine-free medium of a yeast ASL(null) strain transformed with individual mutant ASL alleles. Individual haploid strains were also mated to obtain diploid, "compound heterozygous" yeast. We show that the late onset phenotypes arise in patients because they harbor individual alleles retaining high residual enzymatic activity or because of intragenic complementation among different mutated alleles. In these cases complementation occurs because in the hybrid tetrameric enzyme at least one active site without mutations can be formed or because the differently mutated alleles can stabilize each other, resulting in partial recovery of enzymatic activity. Functional complementation in yeast is simple and reproducible and allows the analysis of large numbers of mutant alleles. Moreover, it can be easily adapted for the analysis of mutations in other genes involved in urea cycle disorders.
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Affiliation(s)
- Eva Trevisson
- Clinical Genetics Unit, University of Padova, 35128 Padova, Italy
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Feng JF, Chen TM, Wen YA, Wang J, Tu ZG. Study of serum argininosuccinate lyase determination for diagnosis of liver diseases. J Clin Lab Anal 2008; 22:220-7. [PMID: 18484660 DOI: 10.1002/jcla.20245] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The objectives of this research were to establish an automatic analysis method for the determination of serum argininosuccinate lyase (ASL) and to investigate the value of serum ASL test in the diagnosis of various liver disorders. According to the chemical reaction catalyzed by ASL, an enzyme-coupled reaction system was designed, and a methodology evaluation of this method was performed. A total of 291 patients with various liver diseases, 247 patients with nonliver disease and 32 healthy controls, were recruited, their serum levels of ASL and traditional hepatopathy markers, including alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyltransferase (GGT), lactate dehydrogenase (LDH), alkaline phosphatase (ALP), and total bilirubin (TBil), were all determined, and their diagnostic values in liver diseases were analyzed and compared. Liver biopsy and the score of histopathological inflammation grading were performed in 31 patients with hepatopathy to explore the correlation between serum ASL level and hepatic histopathological change. A continuous monitoring assay method of serum ASL activity was established, which could be performed with automatic biochemistry analyzer. Methodological evaluation exhibited that the precision of this method was good indicated by the 4.0% intraassay coefficient of variation (CV), and 5.9% interassay CV. The mean recovery was 100.5%, linear range was from 0 to 167.7 U/L, and the lowest detection limit was approximately 0 U/L. All of the tested hepatopathy markers listed above were significantly increased in the liver disease group. However, levels of traditional markers of hepatopathy were all significantly increased at different degrees (all P<0.001) in patients with nonliver diseases; in contrast, there were no significantly increased ASL levels in all non-hepatopathy groups (P=0.335). The receiver operating characteristic (ROC) curve showed that the sensitivity and specificity of ASL were 100% and 91.1% (cutoff value=8 U/L), respectively, in the assessment of liver diseases. In contrast, ALT levels were 97.6% and 24.7%, and AST levels were 83.8% and 28.3% (both cutoff values=40.0 U/L), respectively. A positive correlation (r=0.417, P=0.019) was observed between serum ASL levels (86.9+/-26.5) and scores of histopathological inflammation grading (SHIG) (9.83+/-3.36). The sensitivity and specificity of ALS is much higher than that of ALT and AST for the diagnosis of liver diseases. ASL may be a more valuable marker for estimating hepatopathy.
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Affiliation(s)
- Jia-fu Feng
- Key Laboratory of Laboratory Medical Diagnosis of Education Ministry, Faculty of Laboratory Medicine, Chongqing Medical University, Chongqing, China
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The genetics of hair shaft disorders. J Am Acad Dermatol 2008; 59:1-22; quiz 23-6. [DOI: 10.1016/j.jaad.2008.04.002] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2007] [Revised: 04/03/2008] [Accepted: 04/07/2008] [Indexed: 11/23/2022]
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Deignan JL, Cederbaum SD, Grody WW. Contrasting features of urea cycle disorders in human patients and knockout mouse models. Mol Genet Metab 2008; 93:7-14. [PMID: 17933574 PMCID: PMC2692509 DOI: 10.1016/j.ymgme.2007.08.123] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2007] [Revised: 08/19/2007] [Accepted: 08/19/2007] [Indexed: 10/22/2022]
Abstract
The urea cycle exists for the removal of excess nitrogen from the body. Six separate enzymes comprise the urea cycle, and a deficiency in any one of them causes a urea cycle disorder (UCD) in humans. Arginase is the only urea cycle enzyme with an alternate isoform, though no known human disorder currently exists due to a deficiency in the second isoform. While all of the UCDs usually present with hyperammonemia in the first few days to months of life, most disorders are distinguished by a characteristic profile of plasma amino acid alterations that can be utilized for diagnosis. While enzyme assay is possible, an analysis of the underlying mutation is preferable for an accurate diagnosis. Mouse models for each of the urea cycle disorders exist (with the exception of NAGS deficiency), and for almost all of them, their clinical and biochemical phenotypes rather closely resemble the phenotypes seen in human patients. Consequently, all of the current mouse models are highly useful for future research into novel pharmacological and dietary treatments and gene therapy protocols for the management of urea cycle disorders.
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Affiliation(s)
- Joshua L. Deignan
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA
- The Mental Retardation Research Center, David Geffen School of Medicine at UCLA, Los Angeles, CA
| | - Stephen D. Cederbaum
- Department of Psychiatry, David Geffen School of Medicine at UCLA, Los Angeles, CA
- Department of Pediatrics, David Geffen School of Medicine at UCLA, Los Angeles, CA
- Department of Human Genetics, David Geffen School of Medicine at UCLA, Los Angeles, CA
- The Mental Retardation Research Center, David Geffen School of Medicine at UCLA, Los Angeles, CA
| | - Wayne W. Grody
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA
- Department of Pediatrics, David Geffen School of Medicine at UCLA, Los Angeles, CA
- Department of Human Genetics, David Geffen School of Medicine at UCLA, Los Angeles, CA
- The Mental Retardation Research Center, David Geffen School of Medicine at UCLA, Los Angeles, CA
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Trevisson E, Salviati L, Baldoin MC, Toldo I, Casarin A, Sacconi S, Cesaro L, Basso G, Burlina AB. Argininosuccinate lyase deficiency: mutational spectrum in Italian patients and identification of a novelASLpseudogene. Hum Mutat 2007; 28:694-702. [PMID: 17326097 DOI: 10.1002/humu.20498] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Argininosuccinic aciduria (ASAuria) is an inborn error of metabolism caused by mutations in the argininosuccinate lyase (ASL) gene, which leads to the accumulation of argininosuccinic acid (ASA) in body fluids and severe hyperammonemia. A severe neonatal form and a milder late-onset variant are described. We report a novel ASL pseudogene located in the centromeric region of chromosome 7, 14 novel mutations in the ASL gene, and a novel intronic polymorphism found in a cohort of Italian patients. Our approach relied exclusively on genomic DNA analysis. We found seven missense mutations, two nonsense, three small insertions/deletions, and two splicing mutations. Only two patients harbored previously described mutations, and among the novel variants only two were present in more than one kindred. The pathogenicity of the splicing mutations was demonstrated by a functional splicing assay that employed a hybrid minigene. We also performed molecular modeling using the reported three-dimensional structure of ASL to predict the functional consequences of the missense mutations. There was no genotype-phenotype correlation. Patients with neonatal onset display developmental delay and seizures despite adequate metabolic control. Moreover, hepatomegaly, fibrosis, and abnormal liver function tests are common complications in these patients, but not in patients with the late infancy form. We stress the importance of mutation analysis in patients with ASAuria, to confirm the clinical diagnosis, and to perform DNA-based prenatal diagnosis in future pregnancies of these families.
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Affiliation(s)
- Eva Trevisson
- Department of Pediatrics, University of Padova, Padova, Italy
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Sampaleanu L, Codding P, Lobsanov Y, Tsai M, Smith G, Horvatin C, Howell P. Structural studies of duck delta2 crystallin mutants provide insight into the role of Thr161 and the 280s loop in catalysis. Biochem J 2005; 384:437-47. [PMID: 15320872 PMCID: PMC1134128 DOI: 10.1042/bj20040656] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Delta crystallin, a taxon-specific crystallin present in avian eye lenses, is homologous to the urea cycle enzyme ASL (argininosuccinate lyase). Although there are two delta crystallin isoforms in duck lenses, ddeltac1 (duck delta1 crystallin) and ddeltac2 (duck delta2 crystallin), only ddeltac2 is catalytically active. Previous structural studies have suggested that residues Ser283 and His162 in the multi-subunit active site of ddeltac2/ASL are the putative catalytic acid/base, while the highly conserved, positively charged Lys289 is thought to help stabilize the carbanion intermediate. The strict conservation of a small hydroxy-containing residue (Thr or Ser) at position 161 adjacent to the putative catalytic base, as well as its proximity to the substrate in the S283A ddeltac2 enzyme-substrate complex, prompted us to investigate further the role this residue. Structures of the active T161S and inactive T161D ddeltac2 mutants, as well as T161D complexed with argininosuccinate, have been determined to 2.0 A resolution. The structures suggest that a hydroxy group is required at position 161 to help correctly position the side chain of Lys289 and the fumarate moiety of the substrate. Threonine is probably favoured over serine, because the interaction of its methyl group with Leu206 would restrict its conformational flexibility. Residues larger than Thr or Ser interfere with substrate binding, supporting previous suggestions that correct positioning of the substrate's fumarate moiety is essential for catalysis to occur. The presence of the 280s loop (i.e. a loop formed by residues 270-290) in the 'open' conformation suggests that loop closure, thought to be essential for sequestration of the substrate, may be triggered by the formation of the carbanion or aci-carboxylate intermediates, whose charge distribution more closely mimics that of the sulphate ion found in the active-site region of the inactive ddeltac1. The 280s loop in ddeltac1 is in the closed conformation.
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Affiliation(s)
- Liliana M. Sampaleanu
- *Structural Biology and Biochemistry, Hospital for Sick Children, 555 University Avenue, Toronto, Ontario, Canada M5G 1X8
- †Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada M5S 1A8
| | - Penelope W. Codding
- ‡Chemistry Department, University of Victoria, Victoria, British Columbia, Canada V8W 3V6
| | - Yuri D. Lobsanov
- *Structural Biology and Biochemistry, Hospital for Sick Children, 555 University Avenue, Toronto, Ontario, Canada M5G 1X8
| | - May Tsai
- *Structural Biology and Biochemistry, Hospital for Sick Children, 555 University Avenue, Toronto, Ontario, Canada M5G 1X8
- †Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada M5S 1A8
| | - G. David Smith
- *Structural Biology and Biochemistry, Hospital for Sick Children, 555 University Avenue, Toronto, Ontario, Canada M5G 1X8
| | - Cathy Horvatin
- *Structural Biology and Biochemistry, Hospital for Sick Children, 555 University Avenue, Toronto, Ontario, Canada M5G 1X8
| | - P. Lynne Howell
- *Structural Biology and Biochemistry, Hospital for Sick Children, 555 University Avenue, Toronto, Ontario, Canada M5G 1X8
- †Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada M5S 1A8
- To whom correspondence should be addressed (email )
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Al-Sayed M, Alahmed S, Alsmadi O, Khalil H, Rashed MS, Imtiaz F, Meyer BF. Identification of a common novel mutation in Saudi patients with argininosuccinic aciduria. J Inherit Metab Dis 2005; 28:877-83. [PMID: 16435180 DOI: 10.1007/s10545-005-0081-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2005] [Accepted: 05/09/2005] [Indexed: 10/25/2022]
Abstract
We have identified a common novel mutation (Q354X) in the argininosuccinate lyase (ASL) gene in Saudi patients with argininosuccinic aciduria (ASAuria; McKusick 207900). The two index patients were siblings, had a neonatal onset of the disease and were diagnosed based on the clinical presentation and confirmed by analysis of their dried blood spots (DBS) by tandem mass spectrometry (MS/MS). The ASL gene was then analysed by direct sequencing. A further 28 patients with a confirmed diagnosis of ASAuria based on MS/MS of their DBS were tested by sequencing for the presence of the Q354X mutation. This mutation was found in 14 out of the 28 patients (50%) tested. Our work indicates that the Q354X allele is common, may account for 50% of the abnormal ASL genes in the Saudi population, and is likely to be associated with the neonatal form of the disease. We recommend that all patients diagnosed with ASAuria in Saudi Arabia or of Arab origin be tested for this mutation and for Q116X, which has been described previously. In addition, further analysis is needed to identify other underlying disease mutations for ASAuria in the Saudi population.
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Affiliation(s)
- M Al-Sayed
- Department of Medical Genetics, King Faisal Specialist Hospital & Research Center, PO Box 3354, Riyadh 11211, Saudi Arabia.
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Sampaleanu LM, Yu B, Howell PL. Mutational analysis of duck delta 2 crystallin and the structure of an inactive mutant with bound substrate provide insight into the enzymatic mechanism of argininosuccinate lyase. J Biol Chem 2002; 277:4166-75. [PMID: 11698398 DOI: 10.1074/jbc.m107465200] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The major soluble avian eye lens protein, delta crystallin, is highly homologous to the housekeeping enzyme argininosuccinate lyase (ASL). ASL is part of the urea and arginine-citrulline cycles and catalyzes the reversible breakdown of argininosuccinate to arginine and fumarate. In duck lenses, there are two delta crystallin isoforms that are 94% identical in amino acid sequence. Only the delta2 isoform has maintained ASL activity and has been used to investigate the enzymatic mechanism of ASL. The role of the active site residues Ser-29, Asp-33, Asp-89, Asn-116, Thr-161, His-162, Arg-238, Thr-281, Ser-283, Asn-291, Asp-293, Glu-296, Lys-325, Asp-330, and Lys-331 have been investigated by site-directed mutagenesis, and the structure of the inactive duck delta2 crystallin (ddeltac2) mutant S283A with bound argininosuccinate was determined at 1.96 A resolution. The S283A mutation does not interfere with substrate binding, because the 280's loop (residues 270-290) is in the open conformation and Ala-283 is more than 7 A from the substrate. The substrate is bound in a different conformation to that observed previously indicating a large degree of conformational flexibility in the fumarate moiety when the 280's loop is in the open conformation. The structure of the S283A ddeltac2 mutant and mutagenesis results reveal that a complex network of interactions of both protein residues and water molecules are involved in substrate binding and specificity. Small changes even to residues not involved directly in anchoring the argininosuccinate have a significant effect on catalysis. The results suggest that either His-162 or Thr-161 are responsible for proton abstraction and reinforce the putative role of Ser-283 as the catalytic acid, although we cannot eliminate the possibility that arginine is released in an uncharged form, with the solvent providing the required proton. A detailed enzymatic mechanism of ASL/ddeltac2 is presented.
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Affiliation(s)
- Liliana M Sampaleanu
- Structural Biology and Biochemistry Program, Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada
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Stadler S, Gempel K, Bieger I, Pontz BF, Gerbitz KD, Bauer MF, Hofmann S. Detection of neonatal argininosuccinate lyase deficiency by serum tandem mass spectrometry. J Inherit Metab Dis 2001; 24:370-8. [PMID: 11486903 DOI: 10.1023/a:1010560704092] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Argininosuccinate lyase (ASL) deficiency (McKusick 207900) is an inborn error of the urea cycle. The leading symptom is progressive hyperammonaemia, which is a life-threatening condition, particularly in patients with a neonatal onset. Early diagnosis and treatment of the hyperammonaemia are necessary to improve survival and the long-term outcome of ASL-deficient patients. Currently, the diagnosis of ASL deficiency is based on the measurement of urea cycle intermediates and amino acids by automated quantitative ion exchange chromatography in plasma and urine. Here, we report a newborn presenting with coma and severe hyperammonaemia. ASL deficiency was suspected on the basis of an adapted tandem mass spectrometric (MS-MS) procedure which allows determination of argininosuccinate in addition to the amino acids in serum samples. MS-MS measurements revealed a characteristic increase of argininosuccinate, a moderate increase of citrulline, and lowered levels of arginine and ornithine in the serum of the patient. The diagnosis was confirmed by the detection of a novel homozygous frameshift mutation in exon 14 of the argininosuccinate lyase gene. We propose MS-MS as a diagnostic tool suitable for the rapid detection of specific alterations in the amino acid spectra caused by ASL deficiency.
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Affiliation(s)
- S Stadler
- Institut für Klinische Chemie, Molekulare Diagnostik und Mitochondriale Genetik, Krankenhaus München-Schwabing, Germany
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Linnebank M, Homberger A, Rapp B, Winter C, Marquardt T, Harms E, Koch HG. Two novel mutations (E86A, R113W) in argininosuccinate lyase deficiency and evidence for highly variable splicing of the human argininosuccinate lyase gene. J Inherit Metab Dis 2000; 23:308-12. [PMID: 10896281 DOI: 10.1023/a:1005690005439] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Balkan W, Oates EL, Howard GA, Roos BA. Testes exhibit elevated expression of calcitonin gene-related peptide receptor component protein. Endocrinology 1999; 140:1459-69. [PMID: 10067875 DOI: 10.1210/endo.140.3.6541] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Calcitonin gene-related peptide (CGRP) receptor component protein (RCP) is a novel protein that modulates CGRP responsiveness in a variety of cell types. Using probes based on the isolation of CGRP-RCP complementary DNA (cDNA) from a guinea pig organ of Corti cDNA library, we cloned human (h) and mouse (m) CGRP-RCP cDNAs, both of which encode 148-residue proteins that at the amino acid levels are approximately 88% identical to each other and to the 146-residue guinea pig CGRP-RCP. Northern blot analysis confirmed the presence of CGRP-RCP messenger RNA in all of the human and mouse tissues tested. In these human tissues, hCGRP-RCP messenger RNA (major band at approximately 3.1 kb, minor band at approximately 7.5 kb) was most prevalent in the testis. In the mouse, the highest abundance of CGRP-RCP RNA was clearly in the testis (major band at approximately 1.6 kb, minor band at approximately 1.1 kb). Based on this tissue distribution of RNA, we sought to identify the cells in the murine testis that contained CGRP-RCP protein. Numerous antisera generated against hCGRP-RCP, including one to recombinant hCGRP-RCP, exhibited strong immunoreactivity localized to the head region of spermatozoa. No CGRP-RCP immunoreactivity was observed in other cells at less mature stages of sperm maturation, in Sertoli or interstitial (Leydig) cells, or in human spermatozoa. Murine epididymal (mature) spermatozoa exhibited CGRP-RCP immunoreactivity identical to that of testicular spermatozoa. Spermatozoa that underwent an experimentally induced acrosome reaction (acrosomal discharge) lost their CGRP-RCP immunoreactivity. Therefore, it appears that CGRP-RCP is associated with the acrosome, suggesting that it may play an important role in reproduction.
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Affiliation(s)
- W Balkan
- Geriatric Research, Education, and Clinical Center, Veterans Affairs Medical Center, and Department of Medicine, University of Miami School of Medicine, Florida 33101, USA.
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Use of antipeptide antibodies in molecular and cellular biology. ACTA ACUST UNITED AC 1999. [DOI: 10.1016/s0075-7535(08)70450-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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Howell PL, Turner MA, Christodoulou J, Walker DC, Craig HJ, Simard LR, Ploder L, McInnes RR. Intragenic complementation at the argininosuccinate lyase locus: reconstruction of the active site. J Inherit Metab Dis 1998; 21 Suppl 1:72-85. [PMID: 9686346 DOI: 10.1023/a:1005361724967] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Intragenic complementation has been observed at the argininosuccinate lyase (ASL) locus and the ASL alleles in the ASL-deficient cell strains of two complementation phenotypes have been identified. The frequent complementers, strains that participate in the majority of the complementation events, were found to be either homozygous or heterozygous for the Q286R allele, while the high-activity complementers, those strains in which complementation is associated with a high restoration of activity, were found to be either homozygous or heterozygous for the D87G allele. Direct proof of the intragenic complementation observed at the ASL locus has been obtained with the co-expression of the D87G and Q286R alleles in COS cells. A significant increase in the ASL activity was observed when the two alleles were co-expressed relative to the expression of each mutant allele alone. The increase in activity was comparable to that observed previously in the fibroblast complementation studies. The structure determinations of ASL and the homologous eye lens protein, duck delta II crystallin, have revealed that the active site of ASL is made up of residues from three different monomers. The structural mapping of the Q286 and D87 residues shows that both are located near the active site but that, in any one active site, each is contributed by a different monomer. The molecular symmetry of the ASL protein is such that when mutant monomers combine randomly, one active site will contain both mutations and at least one active site will contain no mutations at all. It is these 'native' active sites in the hybrid Q286R/D87G proteins that give rise to the partial recovery of enzymatic activity observed during intragenic complementation.
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Affiliation(s)
- P L Howell
- Division of Biochemistry Research, Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada
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Walker DC, Christodoulou J, Craig HJ, Simard LR, Ploder L, Howell PL, McInnes RR. Intragenic complementation at the human argininosuccinate lyase locus. Identification of the major complementing alleles. J Biol Chem 1997; 272:6777-83. [PMID: 9045711 DOI: 10.1074/jbc.272.10.6777] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
To determine the molecular and biochemical basis of intragenic complementation observed at the human argininosuccinate lyase (ASL) locus, we identified the ASL alleles in ASL-deficient cell strains with two unique complementation phenotypes: (i) frequent complementers, strains that participated in the majority of complementation events, and (ii) high activity complementers, strains in which complementation was associated with a relatively high level of restoration of ASL activity. Four mutations (Q286R, D87G, A398D, and a deletion of exon 13) were identified in the four strains examined. One of the two frequent complementers was homozygous, and the other heterozygous, for the Q286R allele. Similarly, one of the two high activity complementers was homozygous, and the other heterozygous, for the D87G allele. When the Q286R and D87G mutations were introduced by site-directed mutagenesis into wild-type ASL cDNA, each conferred loss of ASL activity in COS cell transfection assays. To test directly the hypothesis that intragenic complementation occurs at the ASL locus, one of the major complementation events observed previously, between strains carrying the Q286R and D87G alleles, was reconstructed in COS cell transfection assays. A partial restoration of ASL activity, comparable with the increase seen in the fibroblast complementation analysis, was observed on joint cotransfection of these two alleles. The results provide molecular confirmation of the major features of the ASL mutant complementation map, identify the Q286R and D87D alleles as the frequent and high activity complementing alleles, respectively, and provide direct proof of intragenic complementation at the ASL locus.
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Affiliation(s)
- D C Walker
- Department of Genetics, Research Institute, The Hospital for Sick Children, 555 University Avenue, Toronto, Ontario M5G 1X8, Canada
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29
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Sutton VR, Pan Y, Craigen WJ. Regional localization of the mouse argininosuccinate lyase gene to chromosome 5. Mamm Genome 1997; 8:871. [PMID: 9337408 DOI: 10.1007/s003359900600] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- V R Sutton
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA
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30
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Nagasaki A, Gotoh T, Takeya M, Yu Y, Takiguchi M, Matsuzaki H, Takatsuki K, Mori M. Coinduction of nitric oxide synthase, argininosuccinate synthetase, and argininosuccinate lyase in lipopolysaccharide-treated rats. RNA blot, immunoblot, and immunohistochemical analyses. J Biol Chem 1996; 271:2658-62. [PMID: 8576237 DOI: 10.1074/jbc.271.5.2658] [Citation(s) in RCA: 103] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Nitric oxide (NO) is synthesized from arginine by nitric oxide synthase (NOS), and citrulline which is generated can be recycled to arginine by argininosuccinate synthetase (AS) and argininosuccinate lyase (AL). Rats were injected with bacterial lipopolysaccharide (LPS), and expression of the inducible isoform of NOS (iNOS), AS, and AL was analyzed. In RNA blot analysis, iNOS mRNA was undetectable before the LPS treatment but was induced by LPS in the lung, heart, liver, and spleen, and less strongly in the skeletal muscle and testis. AS mRNA was induced in the lung and spleen, and AL mRNA was weakly induced in these tissues. AS and AL mRNAs were abundant in the control liver and remained unchanged after the treatment. Kinetic studies showed that iNOS mRNA increased rapidly in both spleen and lung, reached a maximum 2-5 h after the treatment, and decreased thereafter. On the other hand, AS mRNA increased more slowly and reached a maximum in 6-12 h (by about 10-fold in the spleen and 2-fold in the lung). AL mRNA in the spleen and lung increased slowly and remained high up to 24 h. In immunoblot analysis, increase of iNOS protein was evident in the lung, liver, and spleen, and there was an increase of AS protein in the lung and spleen. In immunohistochemical analysis, macrophages in the spleen that were negative for iNOS and AS before LPS treatment were strongly positive for both iNOS and AS after this treatment. As iNOS, AS, and AL were coinduced in rat tissues and cells, citrulline-arginine recycling seems to be important in NO synthesis under the conditions of stimulation.
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Affiliation(s)
- A Nagasaki
- Department of Molecular Genetics, Kumamoto University School of Medicine, Japan
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31
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Takiguchi M, Mori M. Transcriptional regulation of genes for ornithine cycle enzymes. Biochem J 1995; 312 ( Pt 3):649-59. [PMID: 8554501 PMCID: PMC1136163 DOI: 10.1042/bj3120649] [Citation(s) in RCA: 92] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- M Takiguchi
- Department of Molecular Genetics, Kumamoto University School of Medicine, Japan
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32
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Simpson A, Moss D, Slingsby C. The avian eye lens protein delta-crystallin shows a novel packing arrangement of tetramers in a supramolecular helix. Structure 1995; 3:403-12. [PMID: 7613869 DOI: 10.1016/s0969-2126(01)00171-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
BACKGROUND Little is known of the intermolecular organization of crystallins in the protein-packed eye lens. The tetrameric structure of the 200,000 Da avian delta-crystallin, which is closely related to the enzyme argininosuccinate lyase and is characteristic of the accommodating, soft lens of birds, has recently been solved at atomic resolution at acidic pH. To help understand how delta-crystallin remains soluble at the very high concentrations found in the avian lens we have now crystallized turkey delta-crystallin at around neutral pH and examined its intermolecular interactions. RESULTS Turkey delta-crystallin has been crystallized around neutral pH. The X-ray structure has been solved at 4.5 A resolution in space group C2 with three and a half tetramers in the asymmetric unit. The symmetrical 222 tetramers have a novel packing arrangement consisting of continuous helices, with 7(3)2 non-crystallographic symmetry, in an approximately hexagonal close-packed array. The internal 222 symmetry of the tetramers allows different polymeric chains to be constructed, based on the tetramer-tetramer association observed in the crystalline helix. It is possible to build a model of a tubule of diameter 212 A that is very similar to observed tubules of bovine argininosuccinate lyase. CONCLUSIONS Elements of helical organization may occur in the concentrated solution of the avian eye lens where delta-crystallin is the prominent protein. The symmetry of the tetramer provides a choice in the direction of growth of a helix at each link so that highly hydrated irregular polymers may be formed rather than large compact regular structures that would not be compatible with a transparent lens.
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Affiliation(s)
- A Simpson
- Birkbeck College, Department of Crystallography, London, UK
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33
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Scherer SW, Poorkaj P, Allen T, Kim J, Geshuri D, Nunes M, Soder S, Stephens K, Pagon RA, Patton MA. Fine mapping of the autosomal dominant split hand/split foot locus on chromosome 7, band q21.3-q22.1. Am J Hum Genet 1994; 55:12-20. [PMID: 8023840 PMCID: PMC1918243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Split hand/split foot (SHFD) is a human developmental defect characterized by missing digits, fusion of remaining digits, and a deep median cleft in the hands and feet. Cytogenetic studies of deletions and translocations associated with this disorder have indicated that an autosomal dominant split hand/split foot locus (gene SHFD1) maps to 7q21-q22. To characterize the SHFD1 locus, somatic cell hybrid lines were constructed from cytogenetically abnormal individuals with SHFD. Molecular analysis resulted in the localization of 93 DNA markers to one of 10 intervals surrounding the SHFD1 locus. The translocation breakpoints in four SHFD patients were encompassed by the smallest region of overlap among the SHfD-associated deletions. The order of DNA markers in the SHFD1 critical region has been defined as PON-D7S812-SHFD1-D7S811-ASNS. One DNA marker, D7S811, detected altered restriction enzyme fragments in three patients with translocations when examined by pulsed-field gel electrophoresis (PFGE). These data map SHFD1, a gene that is crucial for human limb differentiation, to a small interval in the q21.3-q22.1 region of human chromosome 7.
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Affiliation(s)
- S W Scherer
- Department of Molecular and Medical Genetics, University of Toronto
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34
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Hani EK, Chan VL. Cloning, characterization, and nucleotide sequence analysis of the argH gene from Campylobacter jejuni TGH9011 encoding argininosuccinate lyase. J Bacteriol 1994; 176:1865-71. [PMID: 8144452 PMCID: PMC205288 DOI: 10.1128/jb.176.7.1865-1871.1994] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The complete structural gene for argininosuccinate lyase (argH) from Campylobacter jejuni TGH9011 has been cloned into Escherichia coli by complementation of an E. coli argH auxotrophic mutant. The gene has been subcloned for sequencing on a 4.1-kb DNA segment and localized by the complementing activity of deletion mutants. The complete DNA sequence of the C. jejuni argH gene was determined. The transcription start point for argH mRNA was determined by primer extension analysis and found to be within the coding sequence of the upstream gene, identified as the phosphoenolpyruvate carboxykinase gene (ppc). The argininosuccinate lyase and the phosphoenolpyruvate carboxykinase reading frames overlap by one base, the second example of this phenomenon in C. jejuni chromosomal genes. The enzyme has a deduced subunit molecular weight of 51,831. Recombinant plasmids containing the argH gene generate a 56-kDa protein and a 43-kDa protein in E. coli maxicells. An alternate translation initiation producing a polypeptide with a deduced molecular mass of 42 kDa may account for the smaller protein observed in sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The C. jejuni argH gene shows nucleotide homology to both yeast and human argininosuccinate lyase genes, and conserved amino acid domains are evident between the corresponding proteins.
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Affiliation(s)
- E K Hani
- Department of Microbiology, University of Toronto, Ontario, Canada
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35
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Li X, Zelenka PS, Piatigorsky J. Differential expression of the two delta-crystallin genes in lens and non-lens tissues: shift favoring delta 2 expression from embryonic to adult chickens. Dev Dyn 1993; 196:114-23. [PMID: 8364221 DOI: 10.1002/aja.1001960205] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Chicken argininosuccinate lyase (ASL)/delta-crystallin, a lens enzyme-crystallin, is encoded in two linked genes (delta 1 and delta 2); only the delta 2 polypeptide contains ASL activity. Here we have quantified delta 1- and delta 2-crystallin mRNA in the lens, cornea, neural retina, heart, and brain at different stages of embryonic development and in 1-wk-old and 1-yr-old chickens by the polymerase chain reaction using internal delta 1 and delta 2 RNA standards. The delta 1/delta 2 mRNA ratio differed for every tissue and was regulated during development. In the embryo there was more delta 1 than delta 2 mRNA in the lens (50-100 times), cornea (3-4 times), and neural retina (2-20 times), about equal amounts of delta 1 and delta 2 mRNA in the heart, and more delta 2 mRNA in the brain (15 times). delta 1-Crystallin mRNA differentially decreased in every tissue after hatching; by contrast, the delta 2 mRNA remained about the same except for the lens, where it decreased 50-fold between 1 wk and 1 yr after hatching. In the 1-yr-old chicken, the delta 2/delta 1 mRNA ratios were 7 in the lens, 175 in the cornea, 22 in the neural retina, 107 in the heart, and 136 in the brain, indicating that delta 2-crystallin is strongly favored in all adult tissues of the chicken. The excess of delta 1 to delta 2 mRNA in the embryonic lens, cornea, and neural retina is intriguing, and suggests some connection with developing transparent eye tissues. Finally, we raise the possibility that expression of both delta-crystallin genes may create tetrameric ASL isoenzymes (perhaps with different specific activities). The unexpected predominance of delta 2 mRNA in the 1-yr-old lens suggests that both the enzymatic and refractive functions of ASL/delta-crystallin are operative and spatially separated, with the enzymatic role present in the cortical fibers and the refractive role in the center of the lens.
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Affiliation(s)
- X Li
- Laboratory of Molecular and Developmental Biology, National Eye Institute, National Institutes of Health, Bethesda, Maryland 20892
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36
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Powell SM, Zalkin H, Dixon JE. Cloning and characterization of the cDNA encoding human adenylosuccinate synthetase. FEBS Lett 1992; 303:4-10. [PMID: 1592113 DOI: 10.1016/0014-5793(92)80465-s] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Adenylosuccinate synthetase (AS) catalyzes the first committed step in the conversion of IMP to AMP. A cDNA was isolated from a human liver library which encodes a protein of 455 amino acids (M(r) of 49,925). Alignments of human, mouse, Dictyostelium discoideum and E. coli AS sequences identify a number of invariant residues which are likely to be important for structure and/or catalysis. The human AS sequence was also 19% identical to the human urea cycle enzyme, argininosuccinate synthetase (ASS), which catalyzes a chemically similar reaction. Both human liver and HeLa AS mRNA showed signals of 2.3 and 2.8 kb. An unmodified N-terminus is required for function of the human AS enzyme in E. coli mutants lacking the bacterial enzyme. The human cDNA provides a means to assess the possible role of AS abnormalities in unclassified, idiopathic cases of gout.
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Affiliation(s)
- S M Powell
- Department of Biochemistry, Purdue University, West Lafayette, IN 49707
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37
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Expression of duck lens delta-crystallin cDNAs in yeast and bacterial hosts. Delta 2-crystallin is an active argininosuccinate lyase. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(18)54573-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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38
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González-Bosch C, Marcote MJ, Hernández-Yago J. Role of polyamines in the transport in vitro of the precursor of ornithine transcarbamylase. Biochem J 1991; 279 ( Pt 3):815-20. [PMID: 1953676 PMCID: PMC1151519 DOI: 10.1042/bj2790815] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Polyamines induce the transport in vitro of the rat liver precursor of ornithine transcarbamylase (pOTC) into isolated rat liver mitochondria. The accumulation of this precursor at the level of binding to the mitochondrial surface has allowed us to establish that polyamines are involved in the interaction of the precursor with the mitochondrial surface. Transport of a chimeric protein having the signal sequence of pOTC fused to a fragment of the cytosolic protein human arginosuccinate lyase was also induced by polyamines. The sensitivity of the pOTC synthesized in vitro and of the chimeric protein to proteinases decreases in the presence of polyamines. This result suggests that polyamines may play a role in modulating the folding of precursors to favour their binding to mitochondria.
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Affiliation(s)
- C González-Bosch
- Instituto de Investigaciones Citológicas de la Caja de Ahorros de Valencia (Centro Asociado del CSIC), Spain
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39
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Loppes R, Michels R, Decroupette I, Joris B. Sequence analysis of the ARG7 gene of Schizosaccharomyces pombe coding for argininosuccinate lyase. Expression of the gene in Saccharomyces cerevisiae. Curr Genet 1991; 19:255-60. [PMID: 1868575 DOI: 10.1007/bf00355051] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The complete nucleotide sequence of the ARG7 gene, coding for argininosuccinate lyase (EC 4.3.2.1), in the fission yeast (Schizosaccharomyces pombe) has been determined. It consists of an open reading frame of 461 codons. The deduced protein has a molecular weight of 51,200 Da. The gene is devoid of introns which is confirmed by the fact that it is expressed in Escherichia coli after spontaneous insertion of a bacterial sequence probably bearing a prokaryotic promoter. A perfect "TATA" box is found at -72 and the major transcription initiation site in Saccharomyces cerevisiae is located at -11 as shown by primer extension experiments. Comparison of the S. pombe lyase with related proteins from other organisms reveals an important degree of conservation except in the carboxyterminal part of the polypeptide. Additionally, a deletion removing 66 amino acids of the carboxy terminus yields an enzyme exhibiting some biological activity. A unique 1,500 b transcript was found in S. cerevisiae when the intact gene was present, but the deleted version of the gene gave rise to at least three transcripts of 1,800, 2,800 and 3,900 b.
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Affiliation(s)
- R Loppes
- Laboratory of Molecular Genetics, University of Liège, Belgium
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40
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Analysis of naturally occurring and site-directed mutations in the argininosuccinate lyase gene. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(19)67785-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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41
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Walker DC, McCloskey DA, Simard LR, McInnes RR. Molecular analysis of human argininosuccinate lyase: mutant characterization and alternative splicing of the coding region. Proc Natl Acad Sci U S A 1990; 87:9625-9. [PMID: 2263616 PMCID: PMC55225 DOI: 10.1073/pnas.87.24.9625] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Argininosuccinic acid lyase (ASAL) deficiency is a clinically heterogeneous autosomal recessive urea cycle disorder. We previously established by complementation analysis that 28 ASAL-deficient patients have heterogeneous mutations in a single gene. To prove that the ASAL structural gene is the affected locus, we sequenced polymerase chain reaction-amplified ASAL cDNA of a representative mutant from the single complementation group. Fibroblast strain 944 (approximately 1% of residual ASAL activity), from a late-onset patient who was the product of a consanguineous mating, had only a single base-pair change in the coding region, a C-283----T transition at a CpG dinucleotide in exon 3. This substitution converts Arg-95 to Cys (R95C), occurs in a stretch of 13 residues that is identical in yeast and human ASAL, and was present in both of the patient's alleles but not in 14 other mutant or 10 normal alleles. Expression in COS cells demonstrated that the R95C mutation produces normal amounts of ASAL mRNA but little protein and less than 1% ASAL activity. We observed that amplified cDNA from mutant 944 and normal cells (liver, keratinocytes, lymphoblasts, and fibroblasts) contained, in addition to the expected 5' 513-base-pair band, a prominent 318-base-pair ASAL band formed by the splicing of exon 2 from the transcript. The short transcript maintains the ASAL reading frame but removes Lys-51, a residue that may be essential for catalysis, since it binds the argininosuccinate substrate. We conclude (i) that the identification of the R95C mutation in strain 944 demonstrates that virtually all ASAL deficiency results from defects in the ASAL structural gene and (ii) that minor alternative splicing of the coding region occurs at the ASAL locus.
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Affiliation(s)
- D C Walker
- Research Institute, Hospital for Sick Children, Toronto, ON, Canada
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42
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Cloning of a cDNA encoding adenylosuccinate lyase by functional complementation in Escherichia coli. J Biol Chem 1990. [DOI: 10.1016/s0021-9258(19)38804-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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43
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Dennis JA, Healy PJ, Beaudet AL, O'Brien WE. Molecular definition of bovine argininosuccinate synthetase deficiency. Proc Natl Acad Sci U S A 1989; 86:7947-51. [PMID: 2813370 PMCID: PMC298189 DOI: 10.1073/pnas.86.20.7947] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Citrullinemia is an inborn error of metabolism due to deficiency of the urea cycle enzyme, argininosuccinate synthetase [L-citrulline:L-aspartate ligase (AMP-forming), EC 6.3.4.5]. The disease was first described in humans but was recently reported in dairy cattle in Australia. Here we report the nucleotide sequence of the normal bovine cDNA for argininosuccinate synthetase and the mutation present in animals with citrullinemia. Analysis of DNA from affected animals by Southern blotting did not readily identify the mutation in the bovine gene. RNA (Northern) blotting revealed a major reduction in the steady-state amount of mRNA in the liver of affected animals to less than 5% of controls. The bovine cDNA was cloned and sequenced and revealed 96% identity with the deduced human sequence at the amino acid level. Starting with mutant bovine liver, the mRNA was reverse-transcribed; the cDNA product was amplified with the polymerase chain reaction, cloned, and sequenced. The sequence revealed a C----T transition converting arginine-86 (CGA) to a nonsense codon (TGA). A second C----T transition represented a polymorphism in proline-175 (CCC----CCT). The mutation and the polymorphism were confirmed by amplification of genomic DNA and demonstration with restriction endonuclease enzymes of both the loss of an Ava II site in DNA from mutant animals at codon 86 and the presence or absence of a Dde I site at codon 175. The loss of the Ava II site can be used for rapid, economical, nonradioactive detection of heterozygotes for bovine citrullinemia.
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Affiliation(s)
- J A Dennis
- Howard Hughes Medical Institute, Baylor College of Medicine, Houston, TX 77030
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44
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Abstract
The functions and expression pattern of urea cycle enzymes have undergone considerable changes during the course of evolution. Sequence analyses shows that urea cycle enzymes from mammals are homologous to microbial enzymes of the arginine-metabolic pathway. Recently, an unexpected relationship was found between argininosuccinate lyase (EC 4.3.2.1), the fourth enzyme of the cycle, and delta-crystallin, a lens structural protein of birds and reptiles.
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45
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Rossi JM, Lindquist S. The intracellular location of yeast heat-shock protein 26 varies with metabolism. J Biophys Biochem Cytol 1989; 108:425-39. [PMID: 2645298 PMCID: PMC2115440 DOI: 10.1083/jcb.108.2.425] [Citation(s) in RCA: 62] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
An antibody highly specific for heat-shock protein (hsp)26, the unique small hsp of yeast, and mutants carrying a deletion of the HSP26 gene were used to examine the physical properties of the protein and to determine its intracellular distribution. The protein was found in complexes with a molecular mass of greater than 500 kD. Thus, it has all of the characteristics, including sequence homology and induction patterns, of small hsps from other organisms. When log-phase cells growing in glucose were heat shocked, hsp26 concentrated in nuclei and continued to concentrate in nuclei when these cells were returned to normal temperatures for recovery. However, hsp26 did not concentrate in nuclei under a variety of other conditions. For example, in early stationary-phase cells hsp26 is induced at normal growth temperatures. This protein was generally distributed throughout the cells, even after heat shock. Similarly, in cells genetically engineered to synthesize hsp26 in the presence of galactose, hsp26 did not concentrate in nuclei, with or without a heat shock. To determine if the failure of hsp26 to concentrate in the nucleus of these cells was due to the fact that the protein had been produced at 25 degrees C or to a difference in the physiological state of the cell, we investigated the distribution of the heat-induced protein in cells grown under several different conditions. In wild-type cells grown in galactose or acetate and in mitochondrial mutants grown in glucose or galactose, hsp26 also failed to concentrate in nuclei with a heat shock. We conclude that the intracellular location of hsp26 in yeast depends upon the physiological state of the cell and not simply upon the presence or absence of heat stress. Our findings may explain why previous investigations of the intracellular localization of small hsps in a variety of organisms have yielded seemingly contradictory results.
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Affiliation(s)
- J M Rossi
- Department of Molecular Genetics and Cell Biology, University of Chicago, Illinois 60637
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46
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Matsubasa T, Takiguchi M, Amaya Y, Matsuda I, Mori M. Structure of the rat argininosuccinate lyase gene: close similarity to chicken delta-crystallin genes. Proc Natl Acad Sci U S A 1989; 86:592-6. [PMID: 2789519 PMCID: PMC286518 DOI: 10.1073/pnas.86.2.592] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Argininosuccinate lyase (EC 4.3.2.1) is an enzyme of arginine biosynthesis and is also involved in the urea cycle in the liver of ureotelic animals. A comparison of cDNA-derived amino acid sequences revealed that argininosuccinate lyase is highly homologous with chicken delta-crystallin, a major structural protein of the eye lens. The gene for the rat argininosuccinate lyase was cloned and its structure was determined. This gene is a single-copy gene about 14 kilobases long and is split into 16 exons. A comparison with chicken delta-crystallin genes revealed that all introns interrupt the protein-coding regions at homologous positions. This close similarity in structural organization provides strong evidence for the view of Piatigorsky et al. [Piatigorsky, J., O'Brien, W. E., Norman, B. L., Kalmuck, K., Wistow, G., Borras, T., Nickerson, J. M. & Wawrousek, E. F. (1988) Proc. Natl. Acad. Sci. USA 85, 3479-3483] that chicken delta 1- and delta 2-crystallin genes evolved by recruitment and duplication of the preexisting argininosuccinate lyase gene and that delta 2-crystallin is probably the direct homologue argininosuccinate lyase.
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Affiliation(s)
- T Matsubasa
- Institute for Medical Genetics, Kumamoto University Medical School, Japan
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47
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Matuo S, Tatsuno M, Kobayashi K, Saheki T, Miyata T, Iwanaga S, Amaya Y, Mori M. Isolation of cDNA clones of human argininosuccinate lyase and corrected amino acid sequence. FEBS Lett 1988; 234:395-9. [PMID: 3391281 DOI: 10.1016/0014-5793(88)80124-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
In the present study, we isolated clones of human argininosuccinate lyase (ASL) cDNA from a liver cDNA library using a clone of rat ASL cDNA and analyzed human ASL cDNA nucleotide sequence. The results reveal that the sequence of human ASL cDNA published by O'Brien et al. in 1986 [Proc. Natl. Acad. Sci USA 83, 7211-7215] had one-base deletions at three independent positions in the coding regions near the COOH-terminus, which caused frame-shift variations in the amino acid sequence. Amino acid sequencing of peptides prepared from purified human liver ASL showed our predicted amino acid sequence to be correct.
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Affiliation(s)
- S Matuo
- Department of Biochemistry, Faculty of Medicine, Kagoshima Univeristy, Japan
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48
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Abstract
Chromosome 7 is frequently associated with chromosome aberrations, rearrangements, and deletions. It also contains many important genes, gene families, and disease loci. This brief review attempts to summarise these and other interesting aspects of chromosome 7. With the rapid accumulation of cloned genes and polymorphic DNA fragments, this chromosome has become an excellent substrate for molecular genetic studies.
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Affiliation(s)
- L C Tsui
- Department of Genetics, Hospital for Sick Children, Toronto, Ontario, Canada
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Piatigorsky J, O'Brien WE, Norman BL, Kalumuck K, Wistow GJ, Borras T, Nickerson JM, Wawrousek EF. Gene sharing by delta-crystallin and argininosuccinate lyase. Proc Natl Acad Sci U S A 1988; 85:3479-83. [PMID: 3368457 PMCID: PMC280235 DOI: 10.1073/pnas.85.10.3479] [Citation(s) in RCA: 182] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The lens structural protein delta-crystallin and the metabolic enzyme argininosuccinate lyase (ASL; L-argininosuccinate arginine-lyase, EC 4.3.2.1) have striking sequence similarity. We have demonstrated that duck delta-crystallin has enormously high ASL activity, while chicken delta-crystallin has lower but significant activity. The lenses of these birds had much greater ASL activity than other tissues, suggesting that ASL is being expressed at unusually high levels as a structural component. In Southern blots of human genomic DNA, chicken delta 1-crystallin cDNA hybridized only to the human ASL gene; moreover, the two chicken delta-crystallin genes accounted for all the sequences in the chicken genome able to cross-hybridize with a human ASL cDNA, with preferential hybridization to the delta 2 gene. Correlations of enzymatic activity and recent data on mRNA levels in the chicken lens suggest that ASL activity depends on expression of the delta 2-crystallin gene. The data indicate that the same gene, at least in ducks, encodes two different functions, an enzyme (ASL) and a structural protein (delta-crystallin), although in chickens specialization and separation of functions may have occurred.
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Affiliation(s)
- J Piatigorsky
- Laboratory of Molecular and Developmental Biology, National Eye Institute, Bethesda, MD 20892
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Watanabe K, Fujii Y, Nakayama K, Ohkubo H, Kuramitsu S, Kagamiyama H, Nakanishi S, Hayaishi O. Structural similarity of bovine lung prostaglandin F synthase to lens epsilon-crystallin of the European common frog. Proc Natl Acad Sci U S A 1988; 85:11-5. [PMID: 2829166 PMCID: PMC279471 DOI: 10.1073/pnas.85.1.11] [Citation(s) in RCA: 121] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Cloned cDNA sequences specific for prostaglandin F (PGF) synthase have been isolated from a cDNA library of bovine lung mRNA sequences. Nucleotide-sequence analyses of cloned cDNA inserts have revealed that PGF synthase consists of a 969-base pair open reading frame coding for a 323-amino acid polypeptide with a Mr of 36,666. The sequence analysis indicates that bovine lung PGF synthase shows 62% identical plus conservative substitutions compared with human liver aldehyde reductase [Wermuth, B., Omar, A., Forster, A., Francesco, C., Wolf, M., Wartburg, J.P., Bullock, B. & Gabbay, K.H. (1987) in Enzymology and Molecular Biology of Carbonyl Metabolism: Aldehyde Dehydrogenase, Aldo-Keto Reductase, and Alcohol Dehydrogenase, eds. Weiner, H. & Flynn, T.G. (Liss, New York), pp. 297-307], which is similar to PGF synthase in molecular weight and substrate specificity. However, comparison of the amino acid sequence of PGF synthase with the National Biomedical Research Foundation protein data base reveals that the sequences of 225 amino acids from C termini of epsilon-crystallin of the European common frog (Rana temporaria) [Tomarev, S.I., Zinovieva, R.D., Dolgilevich, S.M., Luchin, S.V., Krayev, A.S., Skryabin, K.G. & Gause, G.G. (1984) FEBS Lett. 171, 297-302] and of PGF synthase show 77% identical and conservative substitutions without deletions/additions. The result suggests that European common frog lens epsilon-crystallin is identical to bovine lung PGF synthase.
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Affiliation(s)
- K Watanabe
- Hayaishi Bioinformation Transfer Project, Kyoto Laboratory, Research Development Corporation of Japan
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