scholarly journals Haloferax volcanii —a model archaeon for studying DNA replication and repair

Open Biology ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 200293
Author(s):  
Patricia Pérez-Arnaiz ◽  
Ambika Dattani ◽  
Victoria Smith ◽  
Thorsten Allers
Keyword(s):  
Dna Replication ◽  
Genetic Manipulation ◽  
Haloferax Volcanii ◽  
Cellular Biology ◽  
Phenotypic Screening ◽  
The Third ◽  
Dna Replication And Repair ◽  
Repair Pathways ◽  
Halophilic Species ◽  
The Relationship

The tree of life shows the relationship between all organisms based on their common ancestry. Until 1977, it comprised two major branches: prokaryotes and eukaryotes. Work by Carl Woese and other microbiologists led to the recategorization of prokaryotes and the proposal of three primary domains: Eukarya, Bacteria and Archaea. Microbiological, genetic and biochemical techniques were then needed to study the third domain of life. Haloferax volcanii , a halophilic species belonging to the phylum Euryarchaeota, has provided many useful tools to study Archaea, including easy culturing methods, genetic manipulation and phenotypic screening. This review will focus on DNA replication and DNA repair pathways in H. volcanii , how this work has advanced our knowledge of archaeal cellular biology, and how it may deepen our understanding of bacterial and eukaryotic processes.

scholarly journals Serotype-Specific Reorganization of the Mre11 Complex by Adenoviral E4orf3 Proteins

2005 ◽  
Vol 79 (11) ◽  
pp. 6664-6673 ◽  
Author(s):  
Travis H. Stracker ◽  
Darwin V. Lee ◽  
Christian T. Carson ◽  
Felipe D. Araujo ◽  
David A. Ornelles ◽  
...  
Keyword(s):  
Dna Replication ◽  
Protein Production ◽  
Adenovirus Type ◽  
Expression Vectors ◽  
Gene Products ◽  
Late Protein ◽  
Mre11 Complex ◽  
Dna Replication And Repair ◽  
Repair Pathways ◽  
Adenovirus Type 5

ABSTRACT The early transcriptional region 4 (E4) of adenovirus type 5 (Ad5) encodes gene products that modulate splicing, apoptosis, transcription, DNA replication, and repair pathways. Viruses lacking both E4orf3 and E4orf6 have a severe replication defect, partially characterized by the formation of genome concatemers. Concatemer formation is dependent upon the cellular Mre11 complex and is prevented by both the E4orf3 and E4orf6 proteins. The Mre11/Rad50/Nbs1 proteins are targeted for proteasome-mediated degradation by the Ad5 viral E1b55K/E4orf6 complex. The expression of Ad5 E4orf3 causes a redistribution of Mre11 complex members and results in their exclusion from viral replication centers. For this study, we further analyzed the interactions of E4 proteins from different adenovirus serotypes with the Mre11 complex. Analyses of infections with serotypes Ad4 and Ad12 demonstrated that the degradation of Mre11/Rad50/Nbs1 proteins is a conserved feature of the E1b55K/E4orf6 complex. Surprisingly, Nbs1 and Rad50 were localized to the replication centers of both Ad4 and Ad12 viruses prior to Mre11 complex degradation. The transfection of expression vectors for the E4orf3 proteins of Ad4 and Ad12 did not alter the localization of Mre11 complex members. The E4orf3 proteins of Ad4 and Ad12 also failed to complement defects in both concatemer formation and late protein production of a virus with a deletion of E4. These results reveal surprising differences among the highly conserved E4orf3 proteins from different serotypes in the ability to disrupt the Mre11 complex.

scholarly journals The Role of DNA Topoisomerase Binding Protein 1 (TopBP1) in Genome Stability in Arabidopsis

Plants ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 2568
Author(s):  
Pablo Parra-Nunez ◽  
Claire Cooper ◽  
Eugenio Sanchez-Moran
Keyword(s):  
Dna Replication ◽  
Genome Stability ◽  
Topoisomerase Ii ◽  
Binding Protein ◽  
Dna Topoisomerase ◽  
Anaphase Bridges ◽  
Dna Replication And Repair ◽  
The Relationship ◽  
Mitosis And Meiosis

DNA topoisomerase II (TOPII) plays a very important role in DNA topology and in different biological processes such as DNA replication, transcription, repair, and chromosome condensation in higher eukaryotes. TOPII has been found to interact directly with a protein called topoisomerase II binding protein 1 (TopBP1) which also seems to have important roles in DNA replication and repair. In this study, we conducted different experiments to assess the roles of TopBP1 in DNA repair, mitosis, and meiosis, exploring the relationship between TOPII activity and TopBP1. We found that topbp1 mutant seedlings of Arabidopsis thaliana were hypersensitive to cisplatin treatment and the inhibition of TOPII with etoposide produced similar hypersensitivity levels. Furthermore, we recognised that there were no significant differences between the WT and topbp1 seedlings treated with cisplatin and etoposide together, suggesting that the hypersensitivity to cisplatin in the topbp1 mutant could be related to the functional interaction between TOPII and TopBP1. Somatic and meiotic anaphase bridges appeared in the topbp1 mutant at similar frequencies to those when TOPII was inhibited with merbarone, etoposide, or ICFR-187. The effects on meiosis of TOPII inhibition were produced at S phase/G2 stage, suggesting that catenanes could be produced at the onset of meiosis. Thus, if the processing of the catenanes is impaired, some anaphase bridges can be formed. Also, the appearance of anaphase bridges at first and second division is discussed.

scholarly journals The stabilized Pol31–Pol3 interface counteracts Pol32 ablation with differential effects on repair

2021 ◽  
Vol 4 (9) ◽  
pp. e202101138
Author(s):  
Kenji Shimada ◽  
Monika Tsai-Pflugfelder ◽  
Niloofar Davoodi Vijeh Motlagh ◽  
Neda Delgoshaie ◽  
Jeannette Fuchs ◽  
...  
Keyword(s):  
Dna Replication ◽  
Dna Polymerase ◽  
Methyl Methanesulfonate ◽  
Replication Forks ◽  
Differential Effects ◽  
Protein Levels ◽  
Dna Replication And Repair ◽  
Interaction Domains ◽  
Repair Pathways ◽  
Break Induced Replication

DNA polymerase δ, which contains the catalytic subunit, Pol3, Pol31, and Pol32, contributes both to DNA replication and repair. The deletion of pol31 is lethal, and compromising the Pol3–Pol31 interaction domains confers hypersensitivity to cold, hydroxyurea (HU), and methyl methanesulfonate, phenocopying pol32Δ. We have identified alanine-substitutions in pol31 that suppress these deficiencies in pol32Δ cells. We characterize two mutants, pol31-T415A and pol31-W417A, which map to a solvent-exposed loop that mediates Pol31–Pol3 and Pol31–Rev3 interactions. The pol31-T415A substitution compromises binding to the Pol3 CysB domain, whereas Pol31-W417A improves it. Importantly, loss of Pol32, such as pol31-T415A, leads to reduced Pol3 and Pol31 protein levels, which are restored by pol31-W417A. The mutations have differential effects on recovery from acute HU, break-induced replication and trans-lesion synthesis repair pathways. Unlike trans-lesion synthesis and growth on HU, the loss of break-induced replication in pol32Δ cells is not restored by pol31-W417A, highlighting pathway-specific roles for Pol32 in fork-related repair. Intriguingly, CHIP analyses of replication forks on HU showed that pol32Δ and pol31-T415A indirectly destabilize DNA pol α and pol ε at stalled forks.

Differential regulation of cancer progression by CDK4/6 plays a central role in DNA replication and repair pathways

2020 ◽  
pp. canres.2121.2020
Author(s):  
Meiou Dai ◽  
Julien Boudreault ◽  
Ni Wang ◽  
Sophie Poulet ◽  
Girija Daliah ◽  
...  
Keyword(s):  
Dna Replication ◽  
Cancer Progression ◽  
Differential Regulation ◽  
Dna Replication And Repair ◽  
Repair Pathways

Retroaktive Neuverhandlung

2018 ◽  
Vol 63 (1) ◽  
Author(s):  
Daniel Martin Feige
Keyword(s):  
Original Work ◽  
The Other ◽  
Final Part ◽  
Critical Reading ◽  
The Third ◽  
Works Of Art ◽  
The Relationship

Der Beitrag widmet sich der Frage historischer Folgeverhältnisse in der Kunst. Gegenüber dem Gedanken, dass es ein ursprüngliches Werk in der Reihe von Werken gibt, das späteren Werken seinen Sinn gibt, schlägt der Text vor, das Verhältnis umgekehrt zu denken: Im Lichte späterer Werke wird der Sinn früherer Werke neu ausgehandelt. Dazu geht der Text in drei Schritten vor. Im ersten Teil formuliert er unter der Überschrift ›Form‹ in kritischer Abgrenzung zu Danto und Eco mit Adorno den Gedanken, dass Kunstwerke eigensinnig konstituierte Gegenstände sind. Die im Gedanken der Neuverhandlung früherer Werke im Lichte späterer Werke vorausgesetzte Unbestimmtheit des Sinns von Kunstwerken wird im zweiten Teil unter dem Schlagwort ›Zeitlichkeit‹ anhand des Paradigmas der Improvisation erörtert. Der dritte und letzte Teil wendet diese improvisatorische Logik unter dem Label ›Neuaushandlung‹ dann dezidiert auf das Verhältnis von Vorbild und Nachbild an. The article proposes a new understanding of historical succession in the realm of art. In contrast to the idea that there is an original work in the series of works that gives meaning to the works that come later, the text proposes to think it exactly the other way round: in the light of later works, the meanings of earlier works are renegotiated. The text proceeds in three steps to develop this idea. Under the heading ›Form‹ it develops in the first part a critical reading of Danto’s and Eco’s notion of the constitution of the artworks and argues with Adorno that each powerful work develops its own language. In the second part, the vagueness of the meaning of works of art presupposed in the idea of renegotiating earlier works in the light of later works is discussed under the term ›Temporality‹ in terms of the logic of improvisation. The third and final part uses this improvisational logic under the label ›Renegotiation‹ to understand the relationship between model and afterimage in the realm of art.

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