Cloning and expression of human mitochondrial deoxyguanosine kinase cDNA

Wang, Liya; Hellman, Ulf; Eriksson, Staffan

doi:10.1016/0014-5793(96)00623-0

Cited by 61 publications

(55 citation statements)

References 30 publications

(56 reference statements)

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“…The B. acetylicum Gsk protein shows only low or partial homology with E. coli Gsk and other nucleoside kinases which catalyze the same nucleoside phosphorylation. Furthermore, we did not find in the B. acetylicum Gsk sequence any indication of an ATP-binding motif, which is present in other nucleoside kinases (17,37) and other ATP-utilizing enzymes (28).…”

Section: Resultscontrasting

confidence: 69%

Molecular cloning and transcriptional analysis of a guanosine kinase gene of Brevibacterium acetylicum ATCC 953

et al. 1997

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The Brevibacterium acetylicum gsk gene, which encodes guanosine kinase (ATP:guanosine 5-phosphotransferase), a kinase that is involved in guanosine salvage pathways, has been cloned by using the N-terminal amino acid sequence of the purified protein. The cloned chromosomal fragment containing the gsk gene was sequenced and shown to encode a polypeptide of 303 amino acids with a molecular mass of 32,536 Da, which is in good agreement with the measured molecular weight of the purified enzyme. Recombinant Escherichia coli strains harboring plasmids carrying the B. acetylicum gsk gene overexpressed both guanosine and inosine kinase activities. The primary structure of the gsk gene shows similarity to amino acid sequences of sugar kinases classified in the ribokinase family stronger than to those of the E. coli gsk gene encoding guanosine kinase and other nucleoside kinases. Northern blot analysis and primer extension analysis revealed a 1.4-kb transcript and promoter sequences, like the E. coli 70 and B. subtilis A consensus sequences, respectively. These results, together with the nucleotide sequence of the downstream region of gsk, suggested that the organization of B. acetylicum gsk is bicistronic. The second gene, orf2, shows significant similarity to the mutT mutator genes of several organisms, although its function has not yet been identified. The gsk gene was specifically transcribed in the early exponential growth phase, which seems to correspond to the specific guanosine kinase activity profile and suggests a role in controlling the nucleoside monophosphate level by efficiently recycling guanosine when cells are in the early exponential phase.Eukaryotic and prokaryotic cells synthesize purine nucleotides either de novo from small precursors or through salvage pathways from preformed purine. Exogenous and endogenous ribonucleosides are utilized through two salvage pathways. One pathway involves purine nucleoside phosphorylase, which catalyzes the phosphorolysis of ribonucleosides to the corresponding nucleobase and ribose 1-phosphate. The nucleobase is subsequently phosphoribosylated to its corresponding nucleoside monophosphate by purine phosphoribosyltransferase. The other pathway involves ribonucleoside kinase, which catalyzes the direct phosphorylation of the ribonucleoside to the corresponding ribonucleoside 5Ј-monophosphate.Guanosine kinase (ATP:guanosine 5Ј-phosphotransferase) catalyzes the phosphorylation of guanosine to its monophosphate form. Although guanosine kinase activity has been reported both in eukaryotic and prokaryotic cells, in most organisms the existence of guanosine kinase activity is obscure due to difficulties in detecting the weak activity in crude enzyme systems (3). Only the Escherichia coli gsk gene, which encodes guanosine kinase, has been genetically identified (12, 14) and cloned (10, 21). On the other hand, the existence of guanosine kinase activity in Bacillus subtilis has been neglected for the physiological analyses of mutants (9,27).Brevibacterium acetylicum is a corynef...

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Section: Resultscontrasting

confidence: 69%

Molecular cloning and transcriptional analysis of a guanosine kinase gene of Brevibacterium acetylicum ATCC 953

et al. 1997

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“…[133][134][135][136] Cytoplasmic dGK may also contribute to the supply of purine deoxynucleotides for nuclear DNA replication and repair. 132 In this way, nucleoside ana- logues phosphorylated by dGK may exert their cytotoxic effects by interference with both mitochondrial and nuclear DNA synthesis.…”

Section: Deoxyguanosine Kinasementioning

confidence: 99%

Nucleoside analogues: mechanisms of drug resistance and reversal strategies

2001

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“…113) catalyzes the phosphorylation of purine deoxynucleosides and their analogs, using nucleoside triphosphate as phosphate donor (2). The cDNA for dGK has been cloned, and it codes for a 31-kDa protein with an N-terminal mitochondrial leader sequence (15,32). The localization of dGK to mitochondria has been demonstrated in earlier biochemical studies and by recent immunohistological methods (16,20,31).…”

mentioning

confidence: 98%

Antiviral Guanosine Analogs as Substrates for Deoxyguanosine Kinase: Implications for Chemotherapy

Sjöberg

Wang

Eriksson

2001

Antimicrob Agents Chemother

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A highly active form of human recombinant deoxyguanosine kinase (dGK) phosphorylated purine nucleoside analogs active against cytomegalovirus, hepatitis B virus, and human immunodeficiency virus, such as penciclovir, 2,3-dideoxyguanosine and 3-fluoro-2,3-dideoxyguanosine. The antiherpesvirus drug ganciclovir, which is also used in gene therapy, was a substrate for dGK, but with low efficiency. ATP and UTP were both good phosphate donors, with apparent K m values of 6 and 4 M and V max values of 34 and 90 nmol of dGMP/ mg of dGK/min, respectively. With a mixture of 5 mM ATP and 0.05 mM UTP, which represent physiologically relevant concentrations, the activities of dGK with ganciclovir and penciclovir was 1% and approximately 10%, respectively, of that with dGuo. The levels of dGK in different tissues were determined with a selective enzyme assay and the total activities per gram of tissues were similar in liver, brain, heart, and thymus extracts. The fact that the cellular dGK enzyme can phosphorylate antiviral guanosine analogs may help to explain the efficacies and side effects of several forms of chemotherapy.

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Cloning and expression of human mitochondrial deoxyguanosine kinase cDNA

Cited by 61 publications

References 30 publications

Molecular cloning and transcriptional analysis of a guanosine kinase gene of Brevibacterium acetylicum ATCC 953

Molecular cloning and transcriptional analysis of a guanosine kinase gene of Brevibacterium acetylicum ATCC 953

Nucleoside analogues: mechanisms of drug resistance and reversal strategies

Antiviral Guanosine Analogs as Substrates for Deoxyguanosine Kinase: Implications for Chemotherapy

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