scholarly journals TENT4A non-canonical poly(A) polymerase regulates DNA-damage tolerance via multiple pathways which are mutated in endometrial cancer

2020 ◽  
Author(s):  
Umakanta Swain ◽  
Gilgi Friedlander ◽  
Urmila Sehrawat ◽  
Avital Sarusi-Portuguez ◽  
Ron Rotkopf ◽  
...  
Keyword(s):  
Endometrial Cancer ◽  
Dna Polymerase ◽  
Mrna Stability ◽  
Antisense Rna ◽  
Bioinformatics Analysis ◽  
Dna Polymerases ◽  
Dna Lesions ◽  
Dna Damage Tolerance ◽  
Translesion Dna Synthesis ◽  
Cancer Genomes

AbstractTENT4A (PAPD7) is a non-canonical poly(A) polymerase, of which little is known. Here we show that TENT4A regulates multiple biological pathways, and focus on its multilayer regulation of translesion DNA synthesis (TLS), in which unrepaired DNA lesions are bypassed by error-prone DNA polymerases. We show that TENT4A regulates mRNA stability and/or translation of DNA polymerase η and RAD18 E3 ligase, which guides the polymerase to replication stalling sites, and monoubiquitinates PCNA, thereby enabling recruitment of error-prone DNA polymerases to damaged DNA sites. Remarkably, in addition to the effect on RAD18 mRNA stability via controlling its poly(A) tail, TENT4A indirectly regulates RAD18 via the tumor suppressor CYLD, and via the long non-coding antisense RNA PAXIP1-AS2, which had no known function. Knocking down the expression of TENT4A or CYLD, or overexpression of PAXIP1-AS2 led each to reduced amounts of the RAD18 protein and DNA polymerase η, leading to reduced TLS, highlighting PAXIP1-AS2 as a new TLS regulator. Bioinformatics analysis revealed that TLS error-prone DNA polymerase genes and their TENT4A-related regulators are frequently mutated in endometrial cancer genomes, suggesting that TLS is dysregulated in this cancer.

scholarly journals TENT4A Non-Canonical Poly(A) Polymerase Regulates DNA-Damage Tolerance via Multiple Pathways That Are Mutated in Endometrial Cancer

2021 ◽  
Vol 22 (13) ◽  
pp. 6957
Author(s):  
Umakanta Swain ◽  
Gilgi Friedlander ◽  
Urmila Sehrawat ◽  
Avital Sarusi-Portuguez ◽  
Ron Rotkopf ◽  
...  
Keyword(s):  
Endometrial Cancer ◽  
Dna Polymerase ◽  
Mrna Stability ◽  
Antisense Rna ◽  
Bioinformatics Analysis ◽  
Dna Polymerases ◽  
Dna Lesions ◽  
Dna Damage Tolerance ◽  
Translesion Dna Synthesis ◽  
Cancer Genomes

TENT4A (PAPD7) is a non-canonical poly(A) polymerase, of which little is known. Here, we show that TENT4A regulates multiple biological pathways and focuses on its multilayer regulation of translesion DNA synthesis (TLS), in which error-prone DNA polymerases bypass unrepaired DNA lesions. We show that TENT4A regulates mRNA stability and/or translation of DNA polymerase h and RAD18 E3 ligase, which guides the polymerase to replication stalling sites and monoubiquitinates PCNA, thereby enabling recruitment of error-prone DNA polymerases to damaged DNA sites. Remarkably, in addition to the effect on RAD18 mRNA stability via controlling its poly(A) tail, TENT4A indirectly regulates RAD18 via the tumor suppressor CYLD and via the long non-coding antisense RNA PAXIP1-AS2, which had no known function. Knocking down the expression of TENT4A or CYLD, or overexpression of PAXIP1-AS2 led each to reduced amounts of the RAD18 protein and DNA polymerase h, leading to reduced TLS, highlighting PAXIP1-AS2 as a new TLS regulator. Bioinformatics analysis revealed that TLS error-prone DNA polymerase genes and their TENT4A-related regulators are frequently mutated in endometrial cancer genomes, suggesting that TLS is dysregulated in this cancer.

scholarly journals Human DNA Polymerase ι Promotes Replication through a Ring-Closed Minor-Groove Adduct That Adopts a syn Conformation in DNA

2005 ◽  
Vol 25 (19) ◽  
pp. 8748-8754 ◽  
Author(s):  
William T. Wolfle ◽  
Robert E. Johnson ◽  
Irina G. Minko ◽  
R. Stephen Lloyd ◽  
Satya Prakash ◽  
...  
Keyword(s):  
Dna Polymerase ◽  
Dna Polymerases ◽  
Minor Groove ◽  
Dna Lesions ◽  
Unsaturated Aldehyde ◽  
Cyclic Form ◽  
Human Dna ◽  
A Minor ◽  
Dna Polymerase Ι

ABSTRACT Acrolein, an α,β-unsaturated aldehyde, is generated in vivo as the end product of lipid peroxidation and from oxidation of polyamines. The reaction of acrolein with the N 2 group of guanine in DNA leads to the formation of a cyclic adduct, γ-hydroxy-1,N 2-propano-2′-deoxyguanosine (γ-HOPdG). Previously, we have shown that proficient replication through the γ-HOPdG adduct can be mediated by the sequential action of human DNA polymerases (Pols) ι and κ, in which Polι incorporates either pyrimidine opposite γ-HOPdG, but Polκ extends only from the cytosine. Since γ-HOPdG can adopt either a ring-closed cyclic form or a ring-opened form in DNA, to better understand the mechanisms that Pols ι and κ employ to promote replication through this lesion, we have examined the ability of these polymerases to replicate through the structural analogs of γ-HOPdG that are permanently either ring closed or ring opened. Our studies with these model adducts show that whereas the ring-opened form of γ-HOPdG is not inhibitory to synthesis by human Pols η, ι, or κ, only Polι is able to incorporate nucleotides opposite the ring-closed form, which is known to adopt a syn conformation in DNA. From these studies, we infer that (i) Pols η, ι, and κ have the ability to proficiently replicate through minor-groove DNA lesions that do not perturb the Watson-Crick hydrogen bonding of the template base with the incoming nucleotide, and (ii) Polι can accommodate a minor-groove-adducted template purine which adopts a syn conformation in DNA and forms a Hoogsteen base pair with the incoming nucleotide.

scholarly journals DNA polymerase iota and related Rad30–like enzymes

2001 ◽  
Vol 356 (1405) ◽  
pp. 53-60 ◽  
Author(s):  
John P. McDonald ◽  
Agnès Tissier ◽  
Ekaterina G. Frank ◽  
Shigenori Iwai ◽  
Fumio Hanaoka ◽  
...  
Keyword(s):  
Dna Polymerase ◽  
Xeroderma Pigmentosum ◽  
Molecular Mechanisms ◽  
Dna Polymerases ◽  
Cellular Functions ◽  
Translesion Dna Synthesis ◽  
Dna Polymerase Iota ◽  
Biochemical Studies ◽  
Template Dna

Until recently, the molecular mechanisms of translesion DNA synthesis (TLS), a process whereby a damaged base is used as a template for continued replication, was poorly understood. This area of scientific research has, however, been revolutionized by the finding that proteins long implicated in TLS are, in fact, DNA polymerases. Members of this so–called UmuC/DinB/Rev1/Rad30 superfamily of polymerases have been identified in prokaryotes, eukaryotes and archaea. Biochemical studies with the highly purified polymerases reveal that some, but not all, can traverse blocking lesions in template DNA. All of them share a common feature, however, in that they exhibit low fidelity when replicating undamaged DNA. Of particular interest to us is the Rad30 subfamily of polymerases found exclusively in eukaryotes. Humans possess two Rad30 paralogs, Rad30A and Rad30B. The RAD30A gene encodes DNA polymerase η and defects in the protein lead to the xeroderma pigmentosum variant (XP–V) phenotype in humans. Very recently RAD30B has also been shown to encode a novel DNA polymerase, designated as Pol ι. Based upon in vitro studies, it appears that Pol ι has the lowest fidelity of any eukaryotic polymerase studied to date and we speculate as to the possible cellular functions of such a remarkably error–prone DNA polymerase.

scholarly journals Unravelling roles of error-prone DNA polymerases in shaping cancer genomes

Oncogene ◽  
2021 ◽  
Author(s):  
Cyrus Vaziri ◽  
Igor B. Rogozin ◽  
Qisheng Gu ◽  
Di Wu ◽  
Tovah A. Day
Keyword(s):  
Dna Damage ◽  
Dna Repair ◽  
Cancer Cells ◽  
Dna Polymerase ◽  
Genome Stability ◽  
Dna Polymerases ◽  
The Cancer Genome Atlas ◽  
Cancer Genomes ◽  
Recent Developments ◽  
Comprehensive Picture

AbstractMutagenesis is a key hallmark and enabling characteristic of cancer cells, yet the diverse underlying mutagenic mechanisms that shape cancer genomes are not understood. This review will consider the emerging challenge of determining how DNA damage response pathways—both tolerance and repair—act upon specific forms of DNA damage to generate mutations characteristic of tumors. DNA polymerases are typically the ultimate mutagenic effectors of DNA repair pathways. Therefore, understanding the contributions of DNA polymerases is critical to develop a more comprehensive picture of mutagenic mechanisms in tumors. Selection of an appropriate DNA polymerase—whether error-free or error-prone—for a particular DNA template is critical to the maintenance of genome stability. We review different modes of DNA polymerase dysregulation including mutation, polymorphism, and over-expression of the polymerases themselves or their associated activators. Based upon recent findings connecting DNA polymerases with specific mechanisms of mutagenesis, we propose that compensation for DNA repair defects by error-prone polymerases may be a general paradigm molding the mutational landscape of cancer cells. Notably, we demonstrate that correlation of error-prone polymerase expression with mutation burden in a subset of patient tumors from The Cancer Genome Atlas can identify mechanistic hypotheses for further testing. We contrast experimental approaches from broad, genome-wide strategies to approaches with a narrower focus on a few hundred base pairs of DNA. In addition, we consider recent developments in computational annotation of patient tumor data to identify patterns of mutagenesis. Finally, we discuss the innovations and future experiments that will develop a more comprehensive portrait of mutagenic mechanisms in human tumors.

scholarly journals Translesion DNA Synthesis Across Lesions Induced by Oxidative Products of Pyrimidines: An Insight into the Mechanism by Microscale Thermophoresis

2019 ◽  
Vol 20 (20) ◽  
pp. 5012 ◽  
Author(s):  
Ondrej Hrabina ◽  
Viktor Brabec ◽  
Olga Novakova
Keyword(s):  
Dna Synthesis ◽  
Dna Polymerase ◽  
Dna Polymerases ◽  
Dna Duplexes ◽  
Translesion Dna Synthesis ◽  
Processing Enzymes ◽  
Microscale Thermophoresis ◽  
Oxidative Products ◽  
Dna Processing ◽  
Damaged Dna

Oxidative stress in cells can lead to the accumulation of reactive oxygen species and oxidation of DNA precursors. Oxidized nucleotides such as 2’-deoxyribo-5-hydroxyuridin (HdU) and 2’-deoxyribo-5-hydroxymethyluridin (HMdU) can be inserted into DNA during replication and repair. HdU and HMdU have attracted particular interest because they have different effects on damaged-DNA processing enzymes that control the downstream effects of the lesions. Herein, we studied the chemically simulated translesion DNA synthesis (TLS) across the lesions formed by HdU or HMdU using microscale thermophoresis (MST). The thermodynamic changes associated with replication across HdU or HMdU show that the HdU paired with the mismatched deoxyribonucleoside triphosphates disturbs DNA duplexes considerably less than thymidine (dT) or HMdU. Moreover, we also demonstrate that TLS by DNA polymerases across the lesion derived from HdU was markedly less extensive and potentially more mutagenic than that across the lesion formed by HMdU. Thus, DNA polymerization by DNA polymerase η (polη), the exonuclease-deficient Klenow fragment of DNA polymerase I (KF–), and reverse transcriptase from human immunodeficiency virus type 1 (HIV-1 RT) across these pyrimidine lesions correlated with the different stabilization effects of the HdU and HMdU in DNA duplexes revealed by MST. The equilibrium thermodynamic data obtained by MST can explain the influence of the thermodynamic alterations on the ability of DNA polymerases to bypass lesions induced by oxidative products of pyrimidines. The results also highlighted the usefulness of MST in evaluating the impact of oxidative products of pyrimidines on the processing of these lesions by damaged DNA processing enzymes.

scholarly journals Transcriptional Modulator NusA Interacts with Translesion DNA Polymerases in Escherichia coli

2008 ◽  
Vol 191 (2) ◽  
pp. 665-672 ◽  
Author(s):  
Susan E. Cohen ◽  
Veronica G. Godoy ◽  
Graham C. Walker
Keyword(s):  
Escherichia Coli ◽  
Rna Polymerase ◽  
Dna Synthesis ◽  
Dna Polymerase ◽  
Temperature Sensitivity ◽  
Dna Polymerases ◽  
Rna Polymerases ◽  
Translesion Dna Synthesis ◽  
Catalytic Activities ◽  
Translesion Dna

ABSTRACT NusA, a modulator of RNA polymerase, interacts with the DNA polymerase DinB. An increased level of expression of dinB or umuDC suppresses the temperature sensitivity of the nusA11 strain, requiring the catalytic activities of these proteins. We propose that NusA recruits translesion DNA synthesis (TLS) polymerases to RNA polymerases stalled at gaps, coupling TLS to transcription.

scholarly journals Enzymatic Switching Between Archaeal DNA Polymerases Facilitates Abasic Site Bypass

2021 ◽  
Vol 12 ◽  
Author(s):  
Xu Feng ◽  
Baochang Zhang ◽  
Ruyi Xu ◽  
Zhe Gao ◽  
Xiaotong Liu ◽  
...  
Keyword(s):  
Dna Synthesis ◽  
Enzyme Kinetics ◽  
Dna Polymerases ◽  
Dna Lesions ◽  
Abasic Site ◽  
Lesion Bypass ◽  
Translesion Dna Synthesis ◽  
Kinetics Studies ◽  
Abasic Sites ◽  
Y Family

Abasic sites are among the most abundant DNA lesions encountered by cells. Their replication requires actions of specialized DNA polymerases. Herein, two archaeal specialized DNA polymerases were examined for their capability to perform translesion DNA synthesis (TLS) on the lesion, including Sulfolobuss islandicus Dpo2 of B-family, and Dpo4 of Y-family. We found neither Dpo2 nor Dpo4 is efficient to complete abasic sites bypass alone, but their sequential actions promote lesion bypass. Enzyme kinetics studies further revealed that the Dpo4’s activity is significantly inhibited at +1 to +3 site past the lesion, at which Dpo2 efficiently extends the primer termini. Furthermore, their activities are inhibited upon synthesis of 5–6 nt TLS patches. Once handed over to Dpo1, these substrates basically inactivate its exonuclease, enabling the transition from proofreading to polymerization of the replicase. Collectively, by functioning as an “extender” to catalyze further DNA synthesis past the lesion, Dpo2 bridges the activity gap between Dpo4 and Dpo1 in the archaeal TLS process, thus achieving more efficient lesion bypass.

scholarly journals Rev1 promotes replication through UV lesions in conjunction with DNA polymerases η, ι, and κ but not DNA polymerase ζ

2015 ◽  
Vol 29 (24) ◽  
pp. 2588-2602 ◽  
Author(s):  
Jung-Hoon Yoon ◽  
Jeseong Park ◽  
Juan Conde ◽  
Maki Wakamiya ◽  
Louise Prakash ◽  
...  
Keyword(s):  
Dna Polymerase ◽  
Crucial Role ◽  
Genome Stability ◽  
Dna Polymerases ◽  
Translesion Synthesis ◽  
Dna Lesions ◽  
Human Cells ◽  
Uv Lesions ◽  
Human And Mouse

Translesion synthesis (TLS) DNA polymerases (Pols) promote replication through DNA lesions; however, little is known about the protein factors that affect their function in human cells. In yeast, Rev1 plays a noncatalytic role as an indispensable component of Polζ, and Polζ together with Rev1 mediates a highly mutagenic mode of TLS. However, how Rev1 functions in TLS and mutagenesis in human cells has remained unclear. Here we determined the role of Rev1 in TLS opposite UV lesions in human and mouse fibroblasts and showed that Rev1 is indispensable for TLS mediated by Polη, Polι, and Polκ but is not required for TLS by Polζ. In contrast to its role in mutagenic TLS in yeast, Rev1 promotes predominantly error-free TLS opposite UV lesions in humans. The identification of Rev1 as an indispensable scaffolding component for Polη, Polι, and Polκ, which function in TLS in highly specialized ways opposite a diverse array of DNA lesions and act in a predominantly error-free manner, implicates a crucial role for Rev1 in the maintenance of genome stability in humans.

scholarly journals DNA polymerase η is a substrate for calpain: A possible mechanism for pol η retention in UV induced replication foci

2021 ◽  
Author(s):  
Jo-Ann Nettersheim ◽  
Régine Janel-Bintz ◽  
Lauriane Kuhn ◽  
Agnès M Cordonnier
Keyword(s):  
Dna Polymerase ◽  
Calcium Ionophore ◽  
Small Subunit ◽  
Dna Lesions ◽  
Calpain Inhibitor ◽  
Translesion Dna Synthesis ◽  
Calcium Dependent ◽  
Catalytically Active ◽  
Radiation Induced ◽  
Replication Foci

DNA polymerase η (pol η) is specifically required for translesion DNA synthesis across ultraviolet radiation-induced DNA lesions. Recruitment of this error-prone DNA polymerase is tightly regulated during replication to avoid mutagenesis and perturbation of fork progression. Here we report that pol η interacts with the calpain small subunit-1 (CAPNS1), in a yeast two-hybrid screening. This interaction is functional as demonstrated by the ability of endogenous calpain to mediate calcium-dependent cleavage of pol η in cell-free extracts and in living cells treated with a calcium ionophore. The proteolysis of pol η is found to occur at position 465 leading to a catalytically active truncated protein containing the PCNA-interacting motif PIP1. Unexpectedly, cell treatment with the specific calpain inhibitor calpeptin results in a decreased extent of pol η foci after UV irradiation, indicating that calpain positively regulates pol η accumulation in replication foci.

scholarly journals Rad51 recombinase prevents Mre11 nuclease-dependent degradation and excessive PrimPol-mediated elongation of nascent DNA after UV irradiation

2015 ◽  
Vol 112 (48) ◽  
pp. E6624-E6633 ◽  
Author(s):  
María Belén Vallerga ◽  
Sabrina F. Mansilla ◽  
María Belén Federico ◽  
Agustina P. Bertolin ◽  
Vanesa Gottifredi
Keyword(s):  
Dna Polymerase ◽  
Uv Irradiation ◽  
Dna Polymerases ◽  
Strand Break ◽  
S Phase ◽  
Exonuclease Activity ◽  
Replication Forks ◽  
Translesion Dna Synthesis ◽  
Phase Progression ◽  
Uv Lesions

After UV irradiation, DNA polymerases specialized in translesion DNA synthesis (TLS) aid DNA replication. However, it is unclear whether other mechanisms also facilitate the elongation of UV-damaged DNA. We wondered if Rad51 recombinase (Rad51), a factor that escorts replication forks, aids replication across UV lesions. We found that depletion of Rad51 impairs S-phase progression and increases cell death after UV irradiation. Interestingly, Rad51 and the TLS polymerase polη modulate the elongation of nascent DNA in different ways, suggesting that DNA elongation after UV irradiation does not exclusively rely on TLS events. In particular, Rad51 protects the DNA synthesized immediately before UV irradiation from degradation and avoids excessive elongation of nascent DNA after UV irradiation. In Rad51-depleted samples, the degradation of DNA was limited to the first minutes after UV irradiation and required the exonuclease activity of the double strand break repair nuclease (Mre11). The persistent dysregulation of nascent DNA elongation after Rad51 knockdown required Mre11, but not its exonuclease activity, and PrimPol, a DNA polymerase with primase activity. By showing a crucial contribution of Rad51 to the synthesis of nascent DNA, our results reveal an unanticipated complexity in the regulation of DNA elongation across UV-damaged templates.

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