scholarly journals Characterization of a Y-Family DNA Polymerase eta from the Eukaryotic ThermophileAlvinella pompejana

2010 ◽  
Vol 2010 ◽  
pp. 1-13 ◽  
Author(s):  
Sayo Kashiwagi ◽  
Isao Kuraoka ◽  
Yoshie Fujiwara ◽  
Kenichi Hitomi ◽  
Quen J. Cheng ◽  
...  

Human DNA polymeraseη(HsPolη) plays an important role in translesion synthesis (TLS), which allows for replication past DNA damage such as UV-inducedcis-syncyclobutane pyrimidine dimers (CPDs). Here, we characterized ApPolηfrom the thermophilic wormAlvinella pompejana, which inhabits deep-sea hydrothermal vent chimneys. ApPolηshares sequence homology with HsPolηand contains domains for binding ubiquitin and proliferating cell nuclear antigen. Sun-induced UV does not penetrateAlvinella'senvironment; however, this novel DNA polymerase catalyzed efficient and accurate TLS past CPD, as well as 7,8-dihydro-8-oxoguanine and isomers of thymine glycol induced by reactive oxygen species. In addition, we found that ApPolηis more thermostable than HsPolη, as expected from its habitat temperature. Moreover, the activity of this enzyme was retained in the presence of a higher concentration of organic solvents. Therefore, ApPolηprovides a robust, human-like Polηthat is more active after exposure to high temperatures and organic solvents.

2010 ◽  
Vol 191 (5) ◽  
pp. 953-966 ◽  
Author(s):  
Tovah A. Day ◽  
Komariah Palle ◽  
Laura R. Barkley ◽  
Naoko Kakusho ◽  
Ying Zou ◽  
...  

The E3 ubiquitin ligase Rad18 guides DNA Polymerase eta (Polη) to sites of replication fork stalling and mono-ubiquitinates proliferating cell nuclear antigen (PCNA) to facilitate binding of Y family trans-lesion synthesis (TLS) DNA polymerases during TLS. However, it is unclear exactly how Rad18 is regulated in response to DNA damage and how Rad18 activity is coordinated with progression through different phases of the cell cycle. Here we identify Rad18 as a novel substrate of the essential protein kinase Cdc7 (also termed Dbf4/Drf1-dependent Cdc7 kinase [DDK]). A serine cluster in the Polη-binding motif of Rad18 is phosphorylated by DDK. Efficient association of Rad18 with Polη is dependent on DDK and is necessary for redistribution of Polη to sites of replication fork stalling. This is the first demonstration of Rad18 regulation by direct phosphorylation and provides a novel mechanism for integration of S phase progression with postreplication DNA repair to maintain genome stability.


2018 ◽  
Vol 110 (5) ◽  
pp. 707-727 ◽  
Author(s):  
Kodavati Manohar ◽  
Doureradjou Peroumal ◽  
Narottam Acharya

1989 ◽  
Vol 9 (1) ◽  
pp. 57-66
Author(s):  
M Zuber ◽  
E M Tan ◽  
M Ryoji

Proliferating cell nuclear antigen (PCNA) (also called cyclin) is known to stimulate the activity of DNA polymerase delta but not the other DNA polymerases in vitro. We injected a human autoimmune antibody against PCNA into unfertilized eggs of Xenopus laevis and examined the effects of this antibody on the replication of injected plasmid DNA as well as egg chromosomes. The anti-PCNA antibody inhibited plasmid replication by up to 67%, demonstrating that PCNA is involved in plasmid replication in living cells. This result further implies that DNA polymerase delta is necessary for plasmid replication in vivo. Anti-PCNA antibody alone did not block plasmid replication completely, but the residual replication was abolished by coinjection of a monoclonal antibody against DNA polymerase alpha. Anti-DNA polymerase alpha alone inhibited plasmid replication by 63%. Thus, DNA polymerase alpha is also required for plasmid replication in this system. In similar studies on the replication of egg chromosomes, the inhibition by anti-PCNA antibody was only 30%, while anti-DNA polymerase alpha antibody blocked 73% of replication. We concluded that the replication machineries of chromosomes and plasmid differ in their relative content of DNA polymerase delta. In addition, we obtained evidence through the use of phenylbutyl deoxyguanosine, an inhibitor of DNA polymerase alpha, that the structure of DNA polymerase alpha holoenzyme for chromosome replication is significantly different from that for plasmid replication.


2011 ◽  
Vol 23 (2) ◽  
pp. 806-822 ◽  
Author(s):  
Alessandra Amoroso ◽  
Lorenzo Concia ◽  
Caterina Maggio ◽  
Cécile Raynaud ◽  
Catherine Bergounioux ◽  
...  

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