scholarly journals SUMO, a small, but powerful, regulator of double-strand break repair

2017 ◽  
Vol 372 (1731) ◽  
pp. 20160281 ◽  
Author(s):  
Alexander J. Garvin ◽  
Joanna R. Morris
Keyword(s):  
Dna Repair ◽  
Mammalian Cells ◽  
Current Knowledge ◽  
Repair Process ◽  
Strand Break ◽  
Post Translational Modification ◽  
Link Type ◽  
Sumo Conjugation ◽  
Dna Lesion ◽  
Sumo Proteases

The response to a DNA double-stranded break in mammalian cells is a process of sensing and signalling the lesion. It results in halting the cell cycle and local transcription and in the mediation of the DNA repair process itself. The response is launched through a series of post-translational modification signalling events coordinated by phosphorylation and ubiquitination. More recently modifications of proteins by S mall U biquitin-like MO difier (SUMO) isoforms have also been found to be key to coordination of the response (Morris et al. 2009 Nature 462 , 886–890 ( doi:10.1038/nature08593 ); Galanty et al. 2009 Nature 462 , 935–939 ( doi:10.1038/nature08657 )). However our understanding of the role of SUMOylation is slight compared with our growing knowledge of how ubiquitin drives signal amplification and key chromatin interactions. In this review we consider our current knowledge of how SUMO isoforms, SUMO conjugation machinery, SUMO proteases and SUMO-interacting proteins contribute to directing altered chromatin states and to repair-protein kinetics at a double-stranded DNA lesion in mammalian cells. We also consider the gaps in our understanding. This article is part of the themed issue ‘Chromatin modifiers and remodellers in DNA repair and signalling’.

scholarly journals Role of RNF20 in cancer development and progression – a comprehensive review

2018 ◽  
Vol 38 (4) ◽  
Author(s):  
Gautam Sethi ◽  
Muthu K. Shanmugam ◽  
Frank Arfuso ◽  
Alan Prem Kumar
Keyword(s):  
Mammalian Cells ◽  
Genome Instability ◽  
Current Knowledge ◽  
Strand Break ◽  
Cancer Development ◽  
Transcriptional Elongation ◽  
Histone H2a ◽  
Post Translational Modification ◽  
Cell Renal Cell Carcinoma ◽  
Suppressor Activity

Evolving strategies to counter cancer initiation and progression rely on the identification of novel therapeutic targets that exploit the aberrant genetic changes driving oncogenesis. Several chromatin associated enzymes have been shown to influence post-translational modification (PTM) in DNA, histones, and non-histone proteins. Any deregulation of this core group of enzymes often leads to cancer development. Ubiquitylation of histone H2B in mammalian cells was identified over three decades ago. An exciting really interesting new gene (RING) family of E3 ubiquitin ligases, known as RNF20 and RNF40, monoubiquitinates histone H2A at K119 or H2B at K120, is known to function in transcriptional elongation, DNA double-strand break (DSB) repair processes, maintenance of chromatin differentiation, and exerting tumor suppressor activity. RNF20 is somatically altered in breast, lung, prostate cancer, clear cell renal cell carcinoma (ccRCC), and mixed lineage leukemia, and its reduced expression is a key factor in initiating genome instability; and it also functions as one of the significant driving factors of oncogenesis. Loss of RNF20/40 and H2B monoubiquitination (H2Bub1) is found in several cancers and is linked to an aggressive phenotype, and is also an indicator of poor prognosis. In this review, we summarized the current knowledge of RNF20 in chronic inflammation-driven cancers, DNA DSBs, and apoptosis, and its impact on chromatin structure beyond the single nucleosome level.

scholarly journals PP4 phosphatase cooperates in recombinational DNA repair by enhancing double-strand break end resection

2019 ◽  
Vol 47 (20) ◽  
pp. 10706-10727 ◽  
Author(s):  
María Teresa Villoria ◽  
Pilar Gutiérrez-Escribano ◽  
Esmeralda Alonso-Rodríguez ◽  
Facundo Ramos ◽  
Eva Merino ◽  
...  
Keyword(s):  
Dna Damage ◽  
Dna Repair ◽  
Dna Damage Response ◽  
Repair Process ◽  
Strand Break ◽  
Double Strand Break ◽  
Dna Lesion ◽  
Damage Response ◽  
End Resection ◽  
Recombinational Dna Repair

Abstract The role of Rad53 in response to a DNA lesion is central for the accurate orchestration of the DNA damage response. Rad53 activation relies on its phosphorylation by Mec1 and its own autophosphorylation in a manner dependent on the adaptor Rad9. While the mechanism behind Rad53 activation has been well documented, less is known about the processes that counteract its activity along the repair of a DNA adduct. Here, we describe that PP4 phosphatase is required to avoid Rad53 hyper-phosphorylation during the repair of a double-strand break, a process that impacts on the phosphorylation status of multiple factors involved in the DNA damage response. PP4-dependent Rad53 dephosphorylation stimulates DNA end resection by relieving the negative effect that Rad9 exerts over the Sgs1/Dna2 exonuclease complex. Consequently, elimination of PP4 activity affects resection and repair by single-strand annealing, defects that are bypassed by reducing Rad53 hyperphosphorylation. These results confirm that Rad53 phosphorylation is controlled by PP4 during the repair of a DNA lesion and demonstrate that the attenuation of its kinase activity during the initial steps of the repair process is essential to efficiently enhance recombinational DNA repair pathways that depend on long-range resection for their success.

scholarly journals Geminivirus Replication Protein impairs SUMO conjugation of PCNA at two acceptor sites

2018 ◽  
Author(s):  
Manuel Arroyo-Mateos ◽  
Blanca Sabarit ◽  
Francesca Maio ◽  
Miguel A. Sánchez-Durán ◽  
Tabata Rosas-Díaz ◽  
...  
Keyword(s):  
Dna Repair ◽  
Infected Plant ◽  
Plant Cells ◽  
Nuclear Antigen ◽  
Replication Machinery ◽  
In Planta ◽  
Post Translational Modification ◽  
Dna Viruses ◽  
Multifunctional Protein ◽  
Sumo Conjugation

ABSTRACTGeminiviruses are DNA viruses that replicate in nuclei of infected plant cells using the plant DNA replication machinery, including PCNA (Proliferating cellular nuclear antigen), a cofactor that orchestrates genome duplication and maintenance by recruiting crucial players to replication forks. These viruses encode a multifunctional protein, Rep, which is essential for viral replication, induces the accumulation of the host replication machinery and interacts with several host proteins, including PCNA and the SUMO E2 conjugation enzyme (SCE1). Post-translational modification of PCNA by ubiquitin or SUMO plays an essential role in the switching of PCNA between interacting partners during DNA metabolism processes (e.g. replication, recombination, repair, etc.). In yeast, PCNA sumoylation has been associated to DNA repair involving homologous recombination (HR). Previously, we reported that ectopic Rep expression results in very specific changes in the sumoylation pattern of plant cells. In this work, we show, using a reconstituted sumoylation system inEscherichia coli, that tomato PCNA is sumoylated at two residues, K254 and K164, and that co-expression of the geminivirus protein Rep suppresses sumoylation at these lysines. Finally, we confirm that PCNA is sumoylatedin plantaand that Rep also interferes with PCNA sumoylation in plant cells.ImportanceSUMO adducts have a key role in regulating the activity of animal and yeast PCNA on DNA repair and replication. Our work demonstrates for the first time that sumoylation of plant PCNA occurs in plant cells and that a plant virus interferes with this modification. This work marks the importance of sumoylation in allowing viral infection and replication in plants. Moreover, it constitutes a prime example of viral proteins interfering with post-translational modifications of selected host factors to create a proper environment for infection.

scholarly journals Repair of site-specific double-strand breaks in a mammalian chromosome by homologous and illegitimate recombination.

1997 ◽  
Vol 17 (1) ◽  
pp. 267-277 ◽  
Author(s):  
R G Sargent ◽  
M A Brenneman ◽  
J H Wilson
Keyword(s):  
Homologous Recombination ◽  
Mammalian Cells ◽  
Repair Process ◽  
Strand Break ◽  
Double Strand Breaks ◽  
Illegitimate Recombination ◽  
Loss Of Function ◽  
Yeast Saccharomyces Cerevisiae ◽  
Site Specific ◽  
Strand Breaks

In mammalian cells, chromosomal double-strand breaks are efficiently repaired, yet little is known about the relative contributions of homologous recombination and illegitimate recombination in the repair process. In this study, we used a loss-of-function assay to assess the repair of double-strand breaks by homologous and illegitimate recombination. We have used a hamster cell line engineered by gene targeting to contain a tandem duplication of the native adenine phosphoribosyltransferase (APRT) gene with an I-SceI recognition site in the otherwise wild-type APRT+ copy of the gene. Site-specific double-strand breaks were induced by intracellular expression of I-SceI, a rare-cutting endonuclease from the yeast Saccharomyces cerevisiae. I-SceI cleavage stimulated homologous recombination about 100-fold; however, illegitimate recombination was stimulated more than 1,000-fold. These results suggest that illegitimate recombination is an important competing pathway with homologous recombination for chromosomal double-strand break repair in mammalian cells.

scholarly journals Spindle Checkpoint Factors Bub1 and Bub2 Promote DNA Double-Strand Break Repair by Nonhomologous End Joining

2015 ◽  
Vol 35 (14) ◽  
pp. 2448-2463 ◽  
Author(s):  
Matthew Jessulat ◽  
Ramy H. Malty ◽  
Diem-Hang Nguyen-Tran ◽  
Viktor Deineko ◽  
Hiroyuki Aoki ◽  
...  
Keyword(s):  
Dna Repair ◽  
Mammalian Cells ◽  
Large Scale ◽  
Spindle Assembly Checkpoint ◽  
Strand Break ◽  
Nonhomologous End Joining ◽  
Cell Cycle Regulators ◽  
Dna Double Strand Breaks ◽  
End Joining ◽  
Content Type

The nonhomologous end-joining (NHEJ) pathway is essential for the preservation of genome integrity, as it efficiently repairs DNA double-strand breaks (DSBs). Previous biochemical and genetic investigations have indicated that, despite the importance of this pathway, the entire complement of genes regulating NHEJ remains unknown. To address this, we employed a plasmid-based NHEJ DNA repair screen in budding yeast (Saccharomyces cerevisiae) using 369 putative nonessential DNA repair-related components as queries. Among the newly identified genes associated with NHEJ deficiency upon disruption are two spindle assembly checkpoint kinases, Bub1 and Bub2. Both observation of resulting phenotypes and chromatin immunoprecipitation demonstrated that Bub1 and -2, either alone or in combination with cell cycle regulators, are recruited near the DSB, where phosphorylated Rad53 or H2A accumulates. Large-scale proteomic analysis of Bub kinases phosphorylated in response to DNA damage identified previously unknown kinase substrates on Tel1 S/T-Q sites. Moreover, Bub1 NHEJ function appears to be conserved in mammalian cells. 53BP1, which influences DSB repair by NHEJ, colocalizes with human BUB1 and is recruited to the break sites. Thus, while Bub is not a core component of NHEJ machinery, our data support its dual role in mitotic exit and promotion of NHEJ repair in yeast and mammals.

Saturation of a DNA Repair Process in Dividing and Nondividing Mammalian Cells

1987 ◽  
Vol 109 (1) ◽  
pp. 109 ◽  
Author(s):  
Kenneth T. Wheeler ◽  
Garret B. Nelson
Keyword(s):  
Dna Repair ◽  
Mammalian Cells ◽  
Repair Process

scholarly journals Mechanisms of Double-Strand-Break Repair During Gene Targeting in Mammalian Cells

Genetics ◽  
1999 ◽  
Vol 151 (3) ◽  
pp. 1127-1141 ◽  
Author(s):  
Philip Ng ◽  
Mark D Baker
Keyword(s):  
Gene Targeting ◽  
Restriction Enzyme ◽  
Mammalian Cells ◽  
Repair Process ◽  
Strand Break ◽  
Double Strand Break ◽  
Patch Repair ◽  
Restriction Enzyme Site ◽  
Dsb Repair ◽  
Vector Borne

AbstractIn the present study, the mechanism of double-strand-break (DSB) repair during gene targeting at the chromosomal immunoglobulin μ-locus in a murine hybridoma was examined. The gene-targeting assay utilized specially designed insertion vectors genetically marked in the region of homology to the chromosomal μ-locus by six diagnostic restriction enzyme site markers. The restriction enzyme markers permitted the contribution of vector-borne and chromosomal μ-sequences in the recombinant product to be determined. The use of the insertion vectors in conjunction with a plating procedure in which individual integrative homologous recombination events were retained for analysis revealed several important features about the mammalian DSB repair process: The presence of the markers within the region of shared homology did not affect the efficiency of gene targeting.In the majority of recombinants, the vector-borne marker proximal to the DSB was absent, being replaced with the corresponding chromosomal restriction enzyme site. This result is consistent with either formation and repair of a vector-borne gap or an “end” bias in mismatch repair of heteroduplex DNA (hDNA) that favored the chromosomal sequence.Formation of hDNA was frequently associated with gene targeting and, in most cases, began ∼645 bp from the DSB and could encompass a distance of at least 1469 bp.The hDNA was efficiently repaired prior to DNA replication.The repair of adjacent mismatches in hDNA occurred predominantly on the same strand, suggesting the involvement of a long-patch repair mechanism.

H2S signaling in redox regulation of cellular functions

2013 ◽  
Vol 91 (1) ◽  
pp. 8-14 ◽  
Author(s):  
Youngjun Ju ◽  
Weihua Zhang ◽  
Yanxi Pei ◽  
Guangdong Yang
Keyword(s):  
Mammalian Cells ◽  
Redox Regulation ◽  
Molecular Mechanisms ◽  
Current Knowledge ◽  
Redox Homeostasis ◽  
Therapeutic Interventions ◽  
Post Translational Modification ◽  
Cellular Functions ◽  
Future Design ◽  
Cellular Effects

Hydrogen sulfide (H2S) is traditionally recognized as a toxic gas with a rotten-egg smell. In just the last few decades, H2S has been found to be one of a family of gasotransmitters, together with nitric oxide and carbon monoxide, and various physiologic effects of H2S have been reported. Among the most acknowledged molecular mechanisms for the cellular effects of H2S is the regulation of intracellular redox homeostasis and post-translational modification of proteins through S-sulfhydration. On the one side, H2S can promote an antioxidant effect and is cytoprotective; on the other side, H2S stimulates oxidative stress and is cytotoxic. This review summarizes our current knowledge of the antioxidant versus pro-oxidant effects of H2S in mammalian cells and describes the Janus-faced properties of this novel gasotransmitter. The redox regulation for the cellular effects of H2S through S-sulfhydration and the role of H2S in glutathione generation is also recapitulated. A better understanding of H2S-regualted redox homeostasis will pave the way for future design of novel pharmacological and therapeutic interventions for various diseases.

scholarly journals Mechanisms of double-strand break repair in somatic mammalian cells

2009 ◽  
Vol 423 (2) ◽  
pp. 157-168 ◽  
Author(s):  
Andrea J. Hartlerode ◽  
Ralph Scully
Keyword(s):  
Genetic Information ◽  
Mammalian Cells ◽  
Current Knowledge ◽  
Strand Break ◽  
Dna Lesions ◽  
Double Strand Breaks ◽  
End Joining ◽  
Strand Breaks ◽  
Non Homologous End Joining

DNA chromosomal DSBs (double-strand breaks) are potentially hazardous DNA lesions, and their accurate repair is essential for the successful maintenance and propagation of genetic information. Two major pathways have evolved to repair DSBs: HR (homologous recombination) and NHEJ (non-homologous end-joining). Depending on the context in which the break is encountered, HR and NHEJ may either compete or co-operate to fix DSBs in eukaryotic cells. Defects in either pathway are strongly associated with human disease, including immunodeficiency and cancer predisposition. Here we review the current knowledge of how NHEJ and HR are controlled in somatic mammalian cells, and discuss the role of the chromatin context in regulating each pathway. We also review evidence for both co-operation and competition between the two pathways.

scholarly journals PP4 phosphatase cooperates in recombinational DNA repair by enhancing double-strand break end resection

2018 ◽  
Author(s):  
María Teresa Villoria ◽  
Pilar Gutiérrez-Escribano ◽  
Facundo Ramos ◽  
Esmeralda Alonso-Rodríguez ◽  
Eva Merino ◽  
...  
Keyword(s):  
Dna Damage ◽  
Dna Repair ◽  
Dna Damage Response ◽  
Kinase Activity ◽  
Strand Break ◽  
Double Strand Break ◽  
Dna Lesion ◽  
Damage Response ◽  
End Resection ◽  
Recombinational Dna Repair

AbstractThe role of Rad53 in response to a DNA lesion is central for the accurate orchestration of the DNA damage response. Rad53 activation relies on its phosphorylation by the Mec1 kinase and its own auto-phosphorylation in a manner dependent on the adaptor Rad9. While the mechanism behind Rad53 phosphorylation and activation has been well documented, less is known about the processes that counteract its kinase activity during the response to DNA damage. Here, we describe that PP4 phosphatase dephosphorylates Rad53 during the repair of a double-strand break, a process that impacts on the phosphorylation status of multiple factors involved in the DNA damage response. PP4-dependent Rad53 dephosphorylation stimulates DNA end resection by relieving the negative effect that Rad9 exerts over the Sgs1/Dna2 exonuclease complex. Consequently, elimination of PP4 activity affects DNA resection and repair by single-strand annealing, defects that are bypassed by reducing the hyper-phosphorylation state of Rad53 observed in the absence of the phosphatase. These results confirm that Rad53 is one of the main targets of PP4 during the repair of a DNA lesion and demonstrate that the attenuation of its kinase activity during the initial steps of the repair process is essential to efficiently enhance recombinational DNA repair pathways that depend on long-range resection.

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