Deoxyuridine misincorporation causes site-specific mutational lesions in the lacI gene of Escherichia coli

Sedwick, W. David; Brown, Oliver E.; Glickman, Barry W.

doi:10.1016/0027-5107(86)90066-7

Cited by 35 publications

(27 citation statements)

References 34 publications

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“…Loss of these cells might result in demyelination of central nervous system neurons, an analogous condition to that caused by B 12 deficiency in peripheral neurons (43). Folate deficiency might also increase uracil misincorporation in neuronal mitochondrial DNA, resulting in an increase in nick formation and DNA deletions (26). This could have an impact on mitochondrial energy production and increase the generation of reactive oxygen species in neurons and other tissues.…”

Section: Discussionmentioning

confidence: 99%

“…Uracil is excised from DNA by uracil-DNA glycosylase and apyrimidinic endonuclease, generating transient singlestrand breaks (nicks) that could result in a less repairable and more hazardous double-strand break if two opposing nicks are formed (25). Uracil repair-induced double-strand breaks are the likely cause of genetic deletions and duplications in dUTPase mutant Escherichia coli (26). Nicks are also created by glycosylase repair of lesions generated by oxidants, the major endogenous mutagens (14), so interactions between antioxidant and folate deficiencies are expected (27).…”

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confidence: 99%

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Folate deficiency causes uracil misincorporation into human DNA and chromosome breakage: Implications for cancer and neuronal damage

Blount

Mack

Wehr

et al. 1997

Proc. Natl. Acad. Sci. U.S.A.

1,273

902

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Folate deficiency causes massive incorporation of uracil into human DNA (4 million per cell) and chromosome breaks. The likely mechanism is the deficient methylation of dUMP to dTMP and subsequent incorporation of uracil into DNA by DNA polymerase. During repair of uracil in DNA, transient nicks are formed; two opposing nicks could lead to chromosome breaks. Both high DNA uracil levels and elevated micronucleus frequency (a measure of chromosome breaks) are reversed by folate administration. A significant proportion of the U.S. population has low folate levels, in the range associated with elevated uracil misincorporation and chromosome breaks. Such breaks could contribute to the increased risk of cancer and cognitive defects associated with folate deficiency in humans.

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Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

Folate deficiency causes uracil misincorporation into human DNA and chromosome breakage: Implications for cancer and neuronal damage

Blount

Mack

Wehr

et al. 1997

Proc. Natl. Acad. Sci. U.S.A.

1,273

902

View full text Add to dashboard Cite

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“…dUTPase catalyzes dUTP cleavage to dUMP and pyrophosphate, thereby reducing misincorporation of dUTP into the genome (4,5). In addition, dUTPase also plays a role in providing a substrate for thymidylate synthase, which converts dUMP to TMP, a major biosynthetic pathway for TTP (6)(7)(8). Interestingly, a number of viruses, including herpesviruses, poxviruses, adenoviruses, D-type retroviruses, and African swine fever virus (ASFV), encode their own dUTPases, suggesting the importance of dUTPases in the life cycles of these viruses (4,(9)(10)(11).…”

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confidence: 99%

Phosphorylation of Herpes Simplex Virus 1 dUTPase Regulates Viral Virulence and Genome Integrity by Compensating for Low Cellular dUTPase Activity in the Central Nervous System

Arii

Koyanagi

Kawaguchi

2015

J Virol

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A mutation in herpes simplex virus 1 dUTPase (vdUTPase), which precluded its phosphorylation at Ser-187, decreased viral neurovirulence and increased mutation frequency in progeny virus genomes in the brains of mice where endogenous cellular dUTPase activity was relatively low, and overexpression of cellular dUTPase restored viral neurovirulence and mutation frequency altered by the mutation. Thus, phosphorylation of vdUTPase appeared to regulate viral virulence and genome integrity by compensating for low cellular dUTPase activity in vivo. IMPORTANCEMany DNA viruses encode a homolog of host cell dUTPases, which are known to function in accurate replication of cellular DNA genomes. The viral dUTPase activity has long been assumed to play a role in viral replication by preventing mutations in progeny virus genomes if cellular dUTPase activity was not sufficient. Here, we showed that a mutation in herpes simplex virus 1 dUTPase, which precluded its phosphorylation at Ser-187 and reduced its activity, decreased viral neurovirulence and increased mutation frequency in progeny virus genomes in the brains of mice where endogenous cellular dUTPase activity was relatively low. In contrast, overexpression of cellular dUTPase restored viral neurovirulence and mutation frequency altered by the mutation in the brains of mice. This is the first report, to our knowledge, directly showing that viral dUTPase activity regulates viral genome integrity and pathogenicity by compensating for insufficient cellular dUTPase activity in vivo. Preserving the integrity of their genetic information during genome replication is of vital importance for all organisms. Noncanonical nucleotides are constantly generated during nucleotide metabolism, and their misincorporation into the genome during replication may result in increased mutagenesis and overload of the DNA excision repair system, leading to multiple DNA strand breaks and cell death (1, 2). The most common noncanonical nucleoside triphosphate is dUTP, which is continuously produced in the pyrimidine biosynthesis pathway by phosphorylation of dUDP or deamination of dCTP (1, 3). dUTPase catalyzes dUTP cleavage to dUMP and pyrophosphate, thereby reducing misincorporation of dUTP into the genome (4, 5). In addition, dUTPase also plays a role in providing a substrate for thymidylate synthase, which converts dUMP to TMP, a major biosynthetic pathway for TTP (6-8). Interestingly, a number of viruses, including herpesviruses, poxviruses, adenoviruses, D-type retroviruses, and African swine fever virus (ASFV), encode their own dUTPases, suggesting the importance of dUTPases in the life cycles of these viruses (4, 9-11).In this study, we focused on the dUTPase encoded by herpes simplex virus 1 (HSV-1), one of the best-studied members of the Herpesviridae family, which causes a variety of diseases such as mucocutaneous diseases, keratitis, skin diseases, and encephalitis (12). HSV-1 dUTPase (vdUTPase) is encoded by the UL50 gene and is conserved throughout the Herpesviridae family (13,1...

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“…dUTPases catalyze the hydrolysis of dUTP to dUMP and pyrophosphate (10,11). Since DNA polymerases are known to readily misincorporate dUTP into replicating DNA, which causes point mutations and strand breakage, dUTP hydrolysis by dUTPases is necessary for accurate DNA replication (11)(12)(13)(14). dUTPase also plays a role in providing a substrate for thymidylate synthase, which converts dUMP to TMP, a major biosynthetic pathway for TTP (10,11).…”

mentioning

confidence: 99%

Phosphorylation of Herpes Simplex Virus 1 dUTPase Upregulated Viral dUTPase Activity To Compensate for Low Cellular dUTPase Activity for Efficient Viral Replication

Hirohata

Arii

Kawaguchi

2014

J Virol

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We recently reported that herpes simplex virus 1 (HSV-1) protein kinase Us3 phosphorylated viral dUTPase (vdUTPase) at serine 187 (Ser-187) to upregulate its enzymatic activity, which promoted HSV-1 replication in human neuroblastoma SK-N-SH cells but not in human carcinoma HEp-2 cells. In the present study, we showed that endogenous cellular dUTPase activity in SK-N-SH cells was significantly lower than that in HEp-2 cells and that overexpression of cellular dUTPase in SK-N-SH cells increased the replication of an HSV-1 mutant with an alanine substitution for Ser-187 (S187A) in vdUTPase to the wild-type level. In addition, we showed that knockdown of cellular dUTPase in HEp-2 cells significantly reduced replication of the mutant vdUTPase (S187A) virus but not that of wild-type HSV-1. Furthermore, the replacement of Ser-187 in vdUTPase with aspartic acid, which mimics constitutive phosphorylation, and overexpression of cellular dUTPase restored viral replication to the wildtype level in cellular dUTPase knockdown HEp-2 cells. These results indicated that sufficient dUTPase activity was required for efficient HSV-1 replication and supported the hypothesis that Us3 phosphorylation of vdUTPase Ser-187 upregulated vdUTPase activity in host cells with low cellular dUTPase activity to produce efficient viral replication.virus. IMPORTANCEIt has long been assumed that dUTPase activity is important for replication of viruses encoding a dUTPase and that the viral dUTPase (vdUTPase) activity was needed if host cell dUTPase activity was not sufficient for efficient viral replication. In the present study, we showed that the S187A mutation in HSV-1 vdUTPase, which impaired its enzymatic activity, reduced viral replication in SK-N-SH cells, which have low endogenous cellular dUTPase activity, and that overexpression of cellular dUTPase restored viral replication to the wild-type level. We also showed that knockdown of cellular dUTPase in HEp-2 cells, which have higher dUTPase activity than do SK-N-SH cells, reduced replication of HSV-1 with the vdUTPase mutation but had no effect on wild-type virus replication. This is the first report, to our knowledge, directly showing that dUTPase activity is critical for efficient viral replication and that vdUTPase compensates for low host cell dUTPase activity to produce efficient viral replication.

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Deoxyuridine misincorporation causes site-specific mutational lesions in the lacI gene of Escherichia coli

Cited by 35 publications

References 34 publications

Folate deficiency causes uracil misincorporation into human DNA and chromosome breakage: Implications for cancer and neuronal damage

Folate deficiency causes uracil misincorporation into human DNA and chromosome breakage: Implications for cancer and neuronal damage

Phosphorylation of Herpes Simplex Virus 1 dUTPase Regulates Viral Virulence and Genome Integrity by Compensating for Low Cellular dUTPase Activity in the Central Nervous System

Phosphorylation of Herpes Simplex Virus 1 dUTPase Upregulated Viral dUTPase Activity To Compensate for Low Cellular dUTPase Activity for Efficient Viral Replication

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