scholarly journals Identification of novel DNA-damage tolerance genes reveals regulation of translesion DNA synthesis by nucleophosmin

2014 ◽  
Vol 5 (1) ◽  
Author(s):  
Omer Ziv ◽  
Amit Zeisel ◽  
Nataly Mirlas-Neisberg ◽  
Umakanta Swain ◽  
Reinat Nevo ◽  
...  
PLoS ONE ◽  
2019 ◽  
Vol 14 (3) ◽  
pp. e0213383 ◽  
Author(s):  
Masataka Tsuda ◽  
Saki Ogawa ◽  
Masato Ooka ◽  
Kaori Kobayashi ◽  
Kouji Hirota ◽  
...  

PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0252587
Author(s):  
Yuriko Inomata ◽  
Takuya Abe ◽  
Masataka Tsuda ◽  
Shunichi Takeda ◽  
Kouji Hirota

Living organisms are continuously under threat from a vast array of DNA-damaging agents, which impact genome DNA. DNA replication machinery stalls at damaged template DNA. The stalled replication fork is restarted via bypass replication by translesion DNA-synthesis polymerases, including the Y-family polymerases Polη, Polι, and Polκ, which possess the ability to incorporate nucleotides opposite the damaged template. To investigate the division of labor among these polymerases in vivo, we generated POLη−/−, POLι−/−, POLκ−/−, double knockout (KO), and triple knockout (TKO) mutants in all combinations from human TK6 cells. TKO cells exhibited a hypersensitivity to ultraviolet (UV), cisplatin (CDDP), and methyl methanesulfonate (MMS), confirming the pivotal role played by these polymerases in bypass replication of damaged template DNA. POLη−/− cells, but not POLι−/− or POLκ−/− cells, showed a strong sensitivity to UV and CDDP, while TKO cells showed a slightly higher sensitivity to UV and CDDP than did POLη−/− cells. On the other hand, TKO cells, but not all single KO cells, exhibited a significantly higher sensitivity to MMS than did wild-type cells. Consistently, DNA-fiber assay revealed that Polη plays a crucial role in bypassing lesions caused by UV-mimetic agent 4-nitroquinoline-1-oxide and CDDP, while all three polymerases play complementary roles in bypassing MMS-induced damage. Our findings indicate that the three Y-family polymerases play distinctly different roles in bypass replication, according to the type of DNA damage generated on the template strand.


2022 ◽  
Vol 8 ◽  
Author(s):  
Denisse Carvajal-Maldonado ◽  
Lea Drogalis Beckham ◽  
Richard D. Wood ◽  
Sylvie Doublié

DNA polymerases catalyze nucleotidyl transfer, the central reaction in synthesis of DNA polynucleotide chains. They function not only in DNA replication, but also in diverse aspects of DNA repair and recombination. Some DNA polymerases can perform translesion DNA synthesis, facilitating damage tolerance and leading to mutagenesis. In addition to these functions, many DNA polymerases conduct biochemically distinct reactions. This review presents examples of DNA polymerases that carry out nuclease (3ʹ—5′ exonuclease, 5′ nuclease, or end-trimming nuclease) or lyase (5′ dRP lyase) extracurricular activities. The discussion underscores how DNA polymerases have a remarkable ability to manipulate DNA strands, sometimes involving relatively large intramolecular movement.


2020 ◽  
Author(s):  
Yann Benureau ◽  
Caroline Pouvelle ◽  
Eliana Moreira Tavares ◽  
Pauline Dupaigne ◽  
Emmanuelle Despras ◽  
...  

AbstractDNA lesions in S phase threaten genome stability. The DNA damage tolerance (DDT) pathways overcome these obstacles and allow completion of DNA synthesis by the use of specialised translesion (TLS) DNA polymerases or through recombination-related processes. However, how these mechanisms coordinate with each other and with bulk replication remain elusive. To address these issues, we monitored the variation of replication intermediate architecture in response to ultraviolet irradiation using transmission electron microscopy. We show that the TLS polymerase η, able to accurately bypass the major UV lesion and mutated in the skin cancer-prone xeroderma pigmentosum variant (XPV) syndrome, acts at the replication fork to resolve uncoupling and prevent post-replicative gap accumulation. Repriming occurs as a compensatory mechanism when this on-the-fly mechanism cannot operate, and is therefore predominant in XPV cells. Interestingly, our data support a recombination-independent function of RAD51 at the replication fork to sustain repriming. Finally, we provide evidence for the post-replicative commitment of recombination in gap repair and for pioneering observations of in vivo recombination intermediates. Altogether, we propose a chronology of UV damage tolerance in human cells that highlights the key role of polη in shaping this response and ensuring the continuity of DNA synthesis.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tonghui Bi ◽  
Xiaohong Niu ◽  
Chunping Qin ◽  
Wei Xiao

AbstractIn response to UV irradiation, translesion DNA synthesis (TLS) utilizes specialized DNA polymerases to bypass replication-blocking lesions. In a well-established polymerase switch model, Polη is thought to be a preferred TLS polymerase to insert correct nucleotides across from the thymine dimer, and Rev1 plays a scaffold role through physical interaction with Polη and the Rev7 subunit of Polζ for continual DNA synthesis. Defective Polη causes a variant form of xeroderma pigmentosum (XPV), a disease with predisposition to sunlight-induced skin cancer. Previous studies revealed that expression of Rev1 alone is sufficient to confer enhanced UV damage tolerance in mammalian cells, which depends on its physical interaction with Polζ but is independent of Polη, a conclusion that appears to contradict current literature on the critical roles of Polη in TLS. To test a hypothesis that the Rev1 catalytic activity is required to backup Polη in TLS, we found that the Rev1 polymerase-dead mutation is synergistic with either Polη mutation or the Polη-interaction mutation in response to UV-induced DNA damage. On the other hand, functional complementation of polH cells by Polη relies on its physical interaction with Rev1. Hence, our studies reveal critical interactions between Rev1 and Polη in response to UV damage.


2007 ◽  
Vol 402 (2) ◽  
pp. 321-329 ◽  
Author(s):  
Giuseppina Blanca ◽  
Emmanuelle Delagoutte ◽  
Nicolas Tanguy le gac ◽  
Neil P. Johnson ◽  
Giuseppe Baldacci ◽  
...  

Replicative DNA polymerases, such as T4 polymerase, possess both elongation and 3′–5′ exonuclease proofreading catalytic activities. They arrest at the base preceding DNA damage on the coding DNA strand and specialized DNA polymerases have evolved to replicate across the lesion by a process known as TLS (translesion DNA synthesis). TLS is considered to take place in two steps that often require different enzymes, insertion of a nucleotide opposite the damaged template base followed by extension from the inserted nucleotide. We and others have observed that inactivation of the 3′–5′ exonuclease function of T4 polymerase enables TLS across a single site-specific abasic [AP (apurinic/apyrimidinic)] lesion. In the present study we report a role for auxiliary replicative factors in this reaction. When replication is performed with a large excess of DNA template over DNA polymerase in the absence of auxiliary factors, the exo− polymerase (T4 DNA polymerase deficient in the 3′–5′ exonuclease activity) inserts one nucleotide opposite the AP site but does not extend past the lesion. Addition of the clamp processivity factor and the clamp loader complex restores primer extension across an AP lesion on a circular AP-containing DNA substrate by the exo− polymerase, but has no effect on the wild-type enzyme. Hence T4 DNA polymerase exhibits a variety of responses to DNA damage. It can behave as a replicative polymerase or (in the absence of proofreading activity) as a specialized DNA polymerase and carry out TLS. As a specialized polymerase it can function either as an inserter or (with the help of accessory proteins) as an extender. The capacity to separate these distinct functions in a single DNA polymerase provides insight into the biochemical requirements for translesion DNA synthesis.


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