scholarly journals A Single Domain in Human DNA Polymerase ι Mediates Interaction with PCNA: Implications for Translesion DNA Synthesis

2005 ◽  
Vol 25 (3) ◽  
pp. 1183-1190 ◽  
Author(s):  
Lajos Haracska ◽  
Narottam Acharya ◽  
Ildiko Unk ◽  
Robert E. Johnson ◽  
Jerard Hurwitz ◽  
...  
Keyword(s):  
Dna Synthesis ◽  
Tight Binding ◽  
Dna Lesions ◽  
Nuclear Antigen ◽  
Binding Motifs ◽  
Translesion Dna Synthesis ◽  
Nucleotide Incorporation ◽  
Y Family ◽  
Stalled Replication Forks ◽  
Proliferating Cell

ABSTRACT DNA polymerases (Pols) of the Y family rescue stalled replication forks by promoting replication through DNA lesions. Humans have four Y family Pols, η, ι, κ, and Rev1, of which Pols η, ι, and κ have been shown to physically interact with proliferating cell nuclear antigen (PCNA) and be functionally stimulated by it. However, in sharp contrast to the large increase in processivity that PCNA binding imparts to the replicative Pol, Polδ, the processivity of Y family Pols is not enhanced upon PCNA binding. Instead, PCNA binding improves the efficiency of nucleotide incorporation via a reduction in the apparent Km for the nucleotide. Here we show that Polι interacts with PCNA via only one of its conserved PCNA binding motifs, regardless of whether PCNA is bound to DNA or not. The mode of PCNA binding by Polι is quite unlike that in Polδ, where multisite interactions with PCNA provide for a very tight binding of the replicating Pol with PCNA. We discuss the implications of these observations for the accuracy of DNA synthesis during translesion synthesis and for the process of Pol exchange at the lesion site.

scholarly journals Ubiquitin-dependent regulation of translesion polymerases

2010 ◽  
Vol 38 (1) ◽  
pp. 110-115 ◽  
Author(s):  
Abel C.S. Chun ◽  
Dong-Yan Jin
Keyword(s):  
Active Sites ◽  
Dna Lesions ◽  
Nuclear Antigen ◽  
Protein Protein Interaction ◽  
Binding Domains ◽  
Translesion Polymerases ◽  
Y Family ◽  
Stalled Replication Forks ◽  
Proliferating Cell ◽  
Damage Protein

In response to DNA damage, TLS (translesion synthesis) allows replicative bypass of various DNA lesions, which stall normal replication. TLS is achieved by low-fidelity polymerases harbouring less stringent active sites. In humans, Y-family polymerases together with Polζ (polymerase ζ) are responsible for TLS across different types of damage. Protein–protein interaction contributes significantly to the regulation of TLS. REV1 plays a central role in TLS because it interacts with all other Y-family members and Polζ. Ubiquitin-dependent regulatory mechanisms also play important roles in TLS. Ubiquitin-binding domains have been found in TLS polymerases and they might be required for TLS activity. Mono-ubiquitination of PCNA (proliferating-cell nuclear antigen), the central scaffold of TLS polymerases, is thought to promote TLS. In addition, both non-proteolytic and proteolytic polyubiquitination of PCNA and TLS polymerases has been demonstrated. Owing to their low fidelity, the recruitment of TLS polymerases is strictly restricted to stalled replication forks.

scholarly journals Structure of a Mutant Form of Proliferating Cell Nuclear Antigen That Blocks Translesion DNA Synthesis†‡

Biochemistry ◽  
2008 ◽  
Vol 47 (50) ◽  
pp. 13354-13361 ◽  
Author(s):  
Bret D. Freudenthal ◽  
S. Ramaswamy ◽  
Manju M. Hingorani ◽  
M. Todd Washington
Keyword(s):  
Dna Synthesis ◽  
Proliferating Cell Nuclear Antigen ◽  
Nuclear Antigen ◽  
Mutant Form ◽  
Translesion Dna Synthesis ◽  
Translesion Dna ◽  
Proliferating Cell

scholarly journals Stimulation of DNA Synthesis Activity of Human DNA Polymerase κ by PCNA

2002 ◽  
Vol 22 (3) ◽  
pp. 784-791 ◽  
Author(s):  
Lajos Haracska ◽  
Ildiko Unk ◽  
Robert E. Johnson ◽  
Barbara B. Phillips ◽  
Jerard Hurwitz ◽  
...  
Keyword(s):  
Dna Synthesis ◽  
Dna Polymerases ◽  
Protein A ◽  
Dna Lesions ◽  
Nuclear Antigen ◽  
Physical Interaction ◽  
Abasic Site ◽  
Nucleotide Incorporation ◽  
Synthesis Activity ◽  
Factor C

ABSTRACT Humans have three DNA polymerases, Polη, Polκ, and Polι, which are able to promote replication through DNA lesions. However, the mechanism by which these DNA polymerases are targeted to the replication machinery stalled at a lesion site has remained unknown. Here, we provide evidence for the physical interaction of human Polκ (hPolκ) with proliferating cell nuclear antigen (PCNA) and show that PCNA, replication factor C (RFC), and replication protein A (RPA) act cooperatively to stimulate the DNA synthesis activity of hPolκ. The processivity of hPolκ, however, is not significantly increased in the presence of these protein factors. The efficiency (V max/K m ) of correct nucleotide incorporation by hPolκ is enhanced ∼50- to 200-fold in the presence of PCNA, RFC, and RPA, and this increase in efficiency is achieved by a reduction in the apparent K m for the nucleotide. Although in the presence of these protein factors, the efficiency of the insertion of an A nucleotide opposite an abasic site is increased ∼40-fold, this reaction still remains quite inefficient; thus, it is unlikely that hPolκ would bypass an abasic site by inserting a nucleotide opposite the site.

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 Archaeal replicative primases can perform translesion DNA synthesis

2015 ◽  
Vol 112 (7) ◽  
pp. E633-E638 ◽  
Author(s):  
Stanislaw K. Jozwiakowski ◽  
Farimah Borazjani Gholami ◽  
Aidan J. Doherty
Keyword(s):  
Dna Synthesis ◽  
Uv Light ◽  
Small Subunit ◽  
Dna Lesions ◽  
Cyclobutane Pyrimidine Dimers ◽  
Translesion Dna Synthesis ◽  
Template Strand ◽  
Pyrimidine Dimers ◽  
Translesion Dna ◽  
Y Family

DNA replicases routinely stall at lesions encountered on the template strand, and translesion DNA synthesis (TLS) is used to rescue progression of stalled replisomes. This process requires specialized polymerases that perform translesion DNA synthesis. Although prokaryotes and eukaryotes possess canonical TLS polymerases (Y-family Pols) capable of traversing blocking DNA lesions, most archaea lack these enzymes. Here, we report that archaeal replicative primases (Pri S, primase small subunit) can also perform TLS. Archaeal Pri S can bypass common oxidative DNA lesions, such as 8-Oxo-2'-deoxyguanosines and UV light-induced DNA damage, faithfully bypassing cyclobutane pyrimidine dimers. Although it is well documented that archaeal replicases specifically arrest at deoxyuracils (dUs) due to recognition and binding to the lesions, a replication restart mechanism has not been identified. Here, we report that Pri S efficiently replicates past dUs, even in the presence of stalled replicase complexes, thus providing a mechanism for maintaining replication bypass of these DNA lesions. Together, these findings establish that some replicative primases, previously considered to be solely involved in priming replication, are also TLS proficient and therefore may play important roles in damage tolerance at replication forks.

scholarly journals Nontranscriptional Function of FOXO1/DAF-16 Contributes to Translesion DNA Synthesis

2016 ◽  
Vol 36 (21) ◽  
pp. 2755-2766 ◽  
Author(s):  
Hiroaki Daitoku ◽  
Yuta Kaneko ◽  
Kenji Yoshimochi ◽  
Kaori Matsumoto ◽  
Sho Araoi ◽  
...  
Keyword(s):  
Dna Damage ◽  
Dna Synthesis ◽  
Uv Irradiation ◽  
Protein A ◽  
Dna Lesions ◽  
Nuclear Antigen ◽  
Transactivation Domain ◽  
Content Type ◽  
Translesion Dna Synthesis ◽  
Translesion Dna

Forkhead box O (FOXO; DAF-16 in nematodes) transcription factors activate a program of genes that control stress resistance, metabolism, and life span. Given the adverse impact of the stochastic DNA damage on organismal development and aging, we examined the role of FOXO/DAF-16 in UV-induced DNA damage response. Knockdown of FOXO1 but not of FOXO3a increases sensitivity to UV irradiation when exposed during S phase, suggesting a contribution of FOXO1 to translesion DNA synthesis (TLS), a replicative bypass of UV-induced DNA lesions. Actually, FOXO1 depletion results in sustained activation of ATR-Chk1 signaling and a reduction of proliferating cell nuclear antigen (PCNA) monoubiquitination following UV irradiation. FOXO1 does not alter the expression of TLS-related genes, but it binds to replication protein A 1 (RPA1), which coats single-stranded DNA and acts as a scaffold for TLS. InCaenorhabditis elegans,daf-16-null mutants show UV-induced retardation in larval development and are rescued by overexpressing a DAF-16 mutant lacking the transactivation domain but not a mutant whose amino acid substitutions render it unable to interact with RPA1. Thus, our findings demonstrate that FOXO1/DAF-16 is a functional component in TLS independent of its transactivation activity.

Demonstration of cell cycle kinetics in thyroid primary culture by immunostaining of proliferating cell nuclear antigen: differences in cyclic AMP-dependent and -independent mitogenic stimulations

1993 ◽  
Vol 105 (1) ◽  
pp. 69-80 ◽  
Author(s):  
M. Baptist ◽  
J.E. Dumont ◽  
P.P. Roger
Keyword(s):  
Cell Cycle ◽  
Dna Synthesis ◽  
Primary Culture ◽  
Proliferating Cell Nuclear Antigen ◽  
Cell Cycle Progression ◽  
Nuclear Antigen ◽  
Major Influence ◽  
Cell Cycle Kinetics ◽  
Experimental Conditions ◽  
Proliferating Cell

In this study, experimental conditions are described that allowed us to follow the fate of the DNA polymerase delta-associated proliferating cell nuclear antigen (PCNA), by immunolabeling during the overall cell cycle. Differences in subcellular localization or the presence of PCNA allowed us to identify each phase of the cell cycle. Using these cell cycle markers in dog thyroid epithelial cells in primary culture, we found unexpected differences in cell cycle kinetics, in response to stimulations through cAMP-dependent and cAMP-independent pathways. These provide a new dimension to the view that the two pathways are largely separate, but co-operate on DNA synthesis initiation. More precisely, thyrotropin (TSH), acting via cAMP, exerts a potent triggering effect on DNA synthesis, associated with a precocious induction of PCNA appearance. This constitutes the major influence of TSH (cAMP) in determining cell cycle progression, which is only partly moderated by TSH-dependent lengthening of S- and G2-phases.

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