scholarly journals Base-Excision Repair Activity of Uracil-DNA Glycosylase Monitored Using the Latch Zone of α-Hemolysin

2013 ◽  
Vol 135 (51) ◽  
pp. 19347-19353 ◽  
Author(s):  
Qian Jin ◽  
Aaron M. Fleming ◽  
Robert P. Johnson ◽  
Yun Ding ◽  
Cynthia J. Burrows ◽  
...  
Keyword(s):  
Base Excision Repair ◽  
Excision Repair ◽  
Dna Glycosylase ◽  
Uracil Dna Glycosylase ◽  
Repair Activity ◽  
Base Excision

scholarly journals Base Excision Repair Is Limited by Different Proteins in Male Germ Cell Nuclear Extracts Prepared from Young and Old Mice

2002 ◽  
Vol 22 (7) ◽  
pp. 2410-2418 ◽  
Author(s):  
Gabriel W. Intano ◽  
C. Alex McMahan ◽  
John R. McCarrey ◽  
Ronald B. Walter ◽  
Allison E. McKenna ◽  
...  
Keyword(s):  
Germ Cell ◽  
Base Excision Repair ◽  
Excision Repair ◽  
Cell Types ◽  
Dna Glycosylase ◽  
Spermatogenic Cells ◽  
Uracil Dna Glycosylase ◽  
Nuclear Extracts ◽  
Repair Activity ◽  
Base Excision

ABSTRACT The combined observations of elevated DNA repair gene expression, high uracil-DNA glycosylase-initiated base excision repair, and a low spontaneous mutant frequency for a lacI transgene in spermatogenic cells from young mice suggest that base excision repair activity is high in spermatogenic cell types. Notably, the spontaneous mutant frequency of the lacI transgene is greater in spermatogenic cells obtained from old mice, suggesting that germ line DNA repair activity may decline with age. A paternal age effect in spermatogenic cells is recognized for the human population as well. To determine if male germ cell base excision repair activity changes with age, uracil-DNA glycosylase-initiated base excision repair activity was measured in mixed germ cell (i.e., all spermatogenic cell types in adult testis) nuclear extracts prepared from young, middle-aged, and old mice. Base excision repair activity was also assessed in nuclear extracts from premeiotic, meiotic, and postmeiotic spermatogenic cell types obtained from young mice. Mixed germ cell nuclear extracts exhibited an age-related decrease in base excision repair activity that was restored by addition of apurinic/apyrimidinic (AP) endonuclease. Uracil-DNA glycosylase and DNA ligase were determined to be limiting in mixed germ cell nuclear extracts prepared from young animals. Base excision repair activity was only modestly elevated in pachytene spermatocytes and round spermatids relative to other spermatogenic cells. Thus, germ line short-patch base excision repair activity appears to be relatively constant throughout spermatogenesis in young animals, limited by uracil-DNA glycosylase and DNA ligase in young animals, and limited by AP endonuclease in old animals.

scholarly journals Uracil-DNA Glycosylase in Base Excision Repair and Adaptive Immunity

2011 ◽  
Vol 286 (19) ◽  
pp. 16669-16680 ◽  
Author(s):  
Berit Doseth ◽  
Torkild Visnes ◽  
Anders Wallenius ◽  
Ida Ericsson ◽  
Antonio Sarno ◽  
...  
Keyword(s):  
Adaptive Immunity ◽  
Base Excision Repair ◽  
Excision Repair ◽  
Dna Glycosylase ◽  
Uracil Dna Glycosylase ◽  
Base Excision

scholarly journals The p53-Induced Oncogenic Phosphatase PPM1D Interacts with Uracil DNA Glycosylase and Suppresses Base Excision Repair

2004 ◽  
Vol 15 (4) ◽  
pp. 621-634 ◽  
Author(s):  
Xiongbin Lu ◽  
Dora Bocangel ◽  
Bonnie Nannenga ◽  
Hiroshi Yamaguchi ◽  
Ettore Appella ◽  
...  
Keyword(s):  
Base Excision Repair ◽  
Excision Repair ◽  
Dna Glycosylase ◽  
Uracil Dna Glycosylase ◽  
Base Excision

scholarly journals Deficient Uracil Base Excision Repair Leads to Persistent dUMP in HIV Proviruses During Infection of Monocytes and Macrophages

2020 ◽  
Author(s):  
Mesfin Meshesha ◽  
Alexandre Esadze ◽  
Junru Cui ◽  
Natela Churgulia ◽  
Sushil Kumar Sahu ◽  
...  
Keyword(s):  
Base Excision Repair ◽  
Reverse Transcription ◽  
Excision Repair ◽  
Dna Glycosylase ◽  
Target Cells ◽  
Viral Dna ◽  
Uracil Dna Glycosylase ◽  
Monocytes And Macrophages ◽  
Base Excision ◽  
Uracil Base

Abstract Background Non-dividing cells of the myeloid lineage such as monocytes and macrophages are target cells of HIV that have low dNTP pool concentrations and elevated levels of dUTP, which leads to frequent incorporation of dUMP opposite to A during reverse transcription (“uracilation”). One factor determining the fate of dUMP in proviral DNA is the host cell uracil base excision repair (UBER) system. Here we explore the relative UBER capacity of monocytes (MC) and monocyte-derived macrophages (MDM) and the fate of integrated uracilated viruses in both cell types to understand the implications of viral dUMP on HIV diversification and infectivity.Results We find that monocytes are almost completely devoid of functional UBER, while macrophages are mainly deficient in the initial enzyme uracil DNA glycosylase (hUNG2). Accordingly, dUMP persists in viral DNA during the lifetime of a MC and can only be removed after differentiation of MC into MDM. Overexpression of human uracil DNA glycosylase in MDM prior to infection resulted in rapid removal of dUMP from HIV cDNA and near complete depletion of dUMP-containing viral copies. This finding establishes that the low hUNG2 expression level in these cells limits UBER but that hUNG2 is restrictive against uracilated viruses. In contrast, overexpression of hUNG2 after viral integration did not accelerate the excision of uracils, suggesting that they may poorly accessible in the context of chromatin. We found that viral DNA molecules with incorporated dUMP contained unique (+) strand transversion mutations that were not observed when dUMP was absent (G→T, T→A, T→G, A→C). These observations and other considerations suggest that dUMP introduces errors predominantly during (-) strand synthesis when the template is RNA. These mutations may arise from the increased mispairing and duplex destabilizing effects of dUMP relative to dTMP during reverse transcription. Overall, the likelihood of producing a functional virus from in vitro infection of MC is about 50-fold and 300-fold reduced as compared to MDM and activated T cells.Conclusions The results implicate viral dUMP incorporation in MC and MDM as a potential viral diversification and restriction pathway during human HIV infection.

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