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Duval N, Luhrs K, Wilkinson TG, Baresova V, Skopova V, Kmoch S, Vacano GN, Zikanova M, Patterson D. Genetic and metabolomic analysis of AdeD and AdeI mutants of de novo purine biosynthesis: cellular models of de novo purine biosynthesis deficiency disorders. Mol Genet Metab 2013; 108:178-189. [PMID: 23394948 PMCID: PMC4296673 DOI: 10.1016/j.ymgme.2013.01.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2012] [Revised: 01/04/2013] [Accepted: 01/05/2013] [Indexed: 02/06/2023]
Abstract
Purines are molecules essential for many cell processes, including RNA and DNA synthesis, regulation of enzyme activity, protein synthesis and function, energy metabolism and transfer, essential coenzyme function, and cell signaling. Purines are produced via the de novo purine biosynthesis pathway. Mutations in purine biosynthetic genes, for example phosphoribosylaminoimidazole carboxylase/phosphoribosylaminoimidazole succinocarboxamide synthetase (PAICS, E.C. 6.3.2.6/E.C. 4.1.1.21), can lead to developmental anomalies in lower vertebrates. Alterations in PAICS expression in humans have been associated with various types of cancer. Mutations in adenylosuccinate lyase (ADSL, E.C. 4.3.2.2) or 5-aminoimidazole-4-carboxamide ribonucleotide formyltransferase/IMP cyclohydrolase (ATIC, E.C. 2.1.2.3/E.C. 3.5.4.10) lead to inborn errors of metabolism with a range of clinical symptoms, including developmental delay, severe neurological symptoms, and autistic features. The pathogenetic mechanism is unknown for these conditions, and no effective treatments exist. The study of cells carrying mutations in the various de novo purine biosynthesis pathway genes provides one approach to analysis of purine disorders. Here we report the characterization of AdeD Chinese hamster ovary (CHO) cells, which carry genetic mutations encoding p.E177K and p.W363* variants of PAICS. Both mutations impact PAICS structure and completely abolish its biosynthesis. Additionally, we describe a sensitive and rapid analytical method for detection of purine de novo biosynthesis intermediates based on high performance liquid chromatography with electrochemical detection. Using this technique we detected accumulation of AIR in AdeD cells. In AdeI cells, mutant for the ADSL gene, we detected accumulation of SAICAR and SAMP and, somewhat unexpectedly, accumulation of AIR. This method has great potential for metabolite profiling of de novo purine biosynthesis pathway mutants, identification of novel genetic defects of purine metabolism in humans, and elucidating the regulation of this critical metabolic pathway.
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Affiliation(s)
- Nathan Duval
- Eleanor Roosevelt Institute and Department of Biological Sciences, University of Denver, 2101 E. Wesley Ave., Denver, CO 80208, USA
| | - Kyleen Luhrs
- Eleanor Roosevelt Institute and Department of Biological Sciences, University of Denver, 2101 E. Wesley Ave., Denver, CO 80208, USA
| | - Terry G. Wilkinson
- Eleanor Roosevelt Institute and Department of Biological Sciences, University of Denver, 2101 E. Wesley Ave., Denver, CO 80208, USA
| | - Veronika Baresova
- Institute of Inherited Metabolic Disorders, First Faculty of Medicine, Charles University in Prague and General University Hospital in Prague, Ke Karlovu 2, 120 00 Prague 2, Czech Republic
| | - Vaclava Skopova
- Institute of Inherited Metabolic Disorders, First Faculty of Medicine, Charles University in Prague and General University Hospital in Prague, Ke Karlovu 2, 120 00 Prague 2, Czech Republic
| | - Stanislav Kmoch
- Institute of Inherited Metabolic Disorders, First Faculty of Medicine, Charles University in Prague and General University Hospital in Prague, Ke Karlovu 2, 120 00 Prague 2, Czech Republic
| | - Guido N. Vacano
- Eleanor Roosevelt Institute and Department of Biological Sciences, University of Denver, 2101 E. Wesley Ave., Denver, CO 80208, USA
| | - Marie Zikanova
- Institute of Inherited Metabolic Disorders, First Faculty of Medicine, Charles University in Prague and General University Hospital in Prague, Ke Karlovu 2, 120 00 Prague 2, Czech Republic
| | - David Patterson
- Eleanor Roosevelt Institute and Department of Biological Sciences, University of Denver, 2101 E. Wesley Ave., Denver, CO 80208, USA
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