scholarly journals Dynamic targeting of the replication machinery to sites of DNA damage

2004 ◽  
Vol 166 (4) ◽  
pp. 455-463 ◽  
Author(s):  
David A. Solomon ◽  
M. Cristina Cardoso ◽  
Erik S. Knudsen
Keyword(s):  
Dna Damage ◽  
Dna Replication ◽  
Nuclear Antigen ◽  
Replication Machinery ◽  
Dependent Protein ◽  
Specific Proteins ◽  
Turn Over ◽  
Dynamic Exchange ◽  
Replication Factors ◽  
Proliferating Cell

Components of the DNA replication machinery localize into discrete subnuclear foci after DNA damage, where they play requisite functions in repair processes. Here, we find that the replication factors proliferating cell nuclear antigen (PCNA) and RPAp34 dynamically exchange at these repair foci with discrete kinetics, and this behavior is distinct from kinetics during DNA replication. Posttranslational modification is hypothesized to target specific proteins for repair, and we find that accumulation and stability of PCNA at sites of damage requires monoubiquitination. Contrary to the popular notion that phosphorylation on the NH2 terminus of RPAp34 directs the protein for repair, we demonstrate that phosphorylation by DNA-dependent protein kinase enhances RPAp34 turnover at repair foci. Together, these findings support a dynamic exchange model in which multiple repair factors regulated by specific modifications have access to and rapidly turn over at sites of DNA damage.

scholarly journals Human PCNA Structure, Function and Interactions

Biomolecules ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 570 ◽  
Author(s):  
Amaia González-Magaña ◽  
Francisco J. Blanco
Keyword(s):  
Dna Replication ◽  
Structure Function ◽  
Binding Mode ◽  
Nuclear Antigen ◽  
Sequence Motif ◽  
Interacting Protein ◽  
Post Translational Modifications ◽  
Dna Replication And Repair ◽  
Dynamic Exchange ◽  
Proliferating Cell

Proliferating cell nuclear antigen (PCNA) is an essential factor in DNA replication and repair. It forms a homotrimeric ring that embraces the DNA and slides along it, anchoring DNA polymerases and other DNA editing enzymes. It also interacts with regulatory proteins through a sequence motif known as PCNA Interacting Protein box (PIP-box). We here review the latest contributions to knowledge regarding the structure-function relationships in human PCNA, particularly the mechanism of sliding, and of the molecular recognition of canonical and non-canonical PIP motifs. The unique binding mode of the oncogene p15 is described in detail, and the implications of the recently discovered structure of PCNA bound to polymerase δ are discussed. The study of the post-translational modifications of PCNA and its partners may yield therapeutic opportunities in cancer treatment, in addition to illuminating the way PCNA coordinates the dynamic exchange of its many partners in DNA replication and repair.

scholarly journals ATM Protein Physically and Functionally Interacts with Proliferating Cell Nuclear Antigen to Regulate DNA Synthesis

2012 ◽  
Vol 287 (15) ◽  
pp. 12445-12454 ◽  
Author(s):  
Armin M. Gamper ◽  
Serah Choi ◽  
Yoshihiro Matsumoto ◽  
Dibyendu Banerjee ◽  
Alan E. Tomkinson ◽  
...  
Keyword(s):  
Dna Damage ◽  
Dna Replication ◽  
Ionizing Radiation ◽  
Dna Synthesis ◽  
Dna Polymerase ◽  
Proliferating Cell Nuclear Antigen ◽  
Nuclear Antigen ◽  
Atm Kinase ◽  
Atm Protein ◽  
Proliferating Cell

Ataxia telangiectasia (A-T) is a pleiotropic disease, with a characteristic hypersensitivity to ionizing radiation that is caused by biallelic mutations in A-T mutated (ATM), a gene encoding a protein kinase critical for the induction of cellular responses to DNA damage, particularly to DNA double strand breaks. A long known characteristic of A-T cells is their ability to synthesize DNA even in the presence of ionizing radiation-induced DNA damage, a phenomenon termed radioresistant DNA synthesis. We previously reported that ATM kinase inhibition, but not ATM protein disruption, blocks sister chromatid exchange following DNA damage. We now show that ATM kinase inhibition, but not ATM protein disruption, also inhibits DNA synthesis. Investigating a potential physical interaction of ATM with the DNA replication machinery, we found that ATM co-precipitates with proliferating cell nuclear antigen (PCNA) from cellular extracts. Using bacterially purified ATM truncation mutants and in vitro translated PCNA, we showed that the interaction is direct and mediated by the C terminus of ATM. Indeed, a 20-amino acid region close to the kinase domain is sufficient for strong binding to PCNA. This binding is specific to ATM, because the homologous regions of other PIKK members, including the closely related kinase A-T and Rad3-related (ATR), did not bind PCNA. ATM was found to bind two regions in PCNA. To examine the functional significance of the interaction between ATM and PCNA, we tested the ability of ATM to stimulate DNA synthesis by DNA polymerase δ, which is implicated in both DNA replication and DNA repair processes. ATM was observed to stimulate DNA polymerase activity in a PCNA-dependent manner.

scholarly journals Regulation of DNA Replication Licensing and Re-Replication by Cdt1

2021 ◽  
Vol 22 (10) ◽  
pp. 5195
Author(s):  
Hui Zhang
Keyword(s):  
Cell Cycle ◽  
Dna Damage ◽  
Dna Replication ◽  
Genome Stability ◽  
E3 Ligase ◽  
S Phase ◽  
Replication Initiation ◽  
Nuclear Antigen ◽  
Repair Synthesis ◽  
Ubiquitin E3 Ligase

In eukaryotic cells, DNA replication licensing is precisely regulated to ensure that the initiation of genomic DNA replication in S phase occurs once and only once for each mitotic cell division. A key regulatory mechanism by which DNA re-replication is suppressed is the S phase-dependent proteolysis of Cdt1, an essential replication protein for licensing DNA replication origins by loading the Mcm2-7 replication helicase for DNA duplication in S phase. Cdt1 degradation is mediated by CRL4Cdt2 ubiquitin E3 ligase, which further requires Cdt1 binding to proliferating cell nuclear antigen (PCNA) through a PIP box domain in Cdt1 during DNA synthesis. Recent studies found that Cdt2, the specific subunit of CRL4Cdt2 ubiquitin E3 ligase that targets Cdt1 for degradation, also contains an evolutionarily conserved PIP box-like domain that mediates the interaction with PCNA. These findings suggest that the initiation and elongation of DNA replication or DNA damage-induced repair synthesis provide a novel mechanism by which Cdt1 and CRL4Cdt2 are both recruited onto the trimeric PCNA clamp encircling the replicating DNA strands to promote the interaction between Cdt1 and CRL4Cdt2. The proximity of PCNA-bound Cdt1 to CRL4Cdt2 facilitates the destruction of Cdt1 in response to DNA damage or after DNA replication initiation to prevent DNA re-replication in the cell cycle. CRL4Cdt2 ubiquitin E3 ligase may also regulate the degradation of other PIP box-containing proteins, such as CDK inhibitor p21 and histone methylase Set8, to regulate DNA replication licensing, cell cycle progression, DNA repair, and genome stability by directly interacting with PCNA during DNA replication and repair synthesis.

scholarly journals Maneuvers on PCNA Rings during DNA Replication and Repair

Genes ◽  
2018 ◽  
Vol 9 (8) ◽  
pp. 416 ◽  
Author(s):  
Dea Slade
Keyword(s):  
Dna Replication ◽  
Protein Interactions ◽  
Proliferating Cell Nuclear Antigen ◽  
Binding Proteins ◽  
Nuclear Antigen ◽  
Vast Number ◽  
Post Translational Modifications ◽  
Dna Replication And Repair ◽  
Replicative Polymerases ◽  
Proliferating Cell

DNA replication and repair are essential cellular processes that ensure genome duplication and safeguard the genome from deleterious mutations. Both processes utilize an abundance of enzymatic functions that need to be tightly regulated to ensure dynamic exchange of DNA replication and repair factors. Proliferating cell nuclear antigen (PCNA) is the major coordinator of faithful and processive replication and DNA repair at replication forks. Post-translational modifications of PCNA, ubiquitination and acetylation in particular, regulate the dynamics of PCNA-protein interactions. Proliferating cell nuclear antigen (PCNA) monoubiquitination elicits ‘polymerase switching’, whereby stalled replicative polymerase is replaced with a specialized polymerase, while PCNA acetylation may reduce the processivity of replicative polymerases to promote homologous recombination-dependent repair. While regulatory functions of PCNA ubiquitination and acetylation have been well established, the regulation of PCNA-binding proteins remains underexplored. Considering the vast number of PCNA-binding proteins, many of which have similar PCNA binding affinities, the question arises as to the regulation of the strength and sequence of their binding to PCNA. Here I provide an overview of post-translational modifications on both PCNA and PCNA-interacting proteins and discuss their relevance for the regulation of the dynamic processes of DNA replication and repair.

scholarly journals Interactions between Telomerase and Primase Physically Link the Telomere and Chromosome Replication Machinery

2002 ◽  
Vol 22 (16) ◽  
pp. 5859-5868 ◽  
Author(s):  
Saugata Ray ◽  
Zemfira Karamysheva ◽  
Libin Wang ◽  
Dorothy E. Shippen ◽  
Carolyn M. Price
Keyword(s):  
De Novo ◽  
Telomerase Activity ◽  
Nuclear Antigen ◽  
Replication Machinery ◽  
Developmentally Regulated ◽  
Coordinate Regulation ◽  
Euplotes Crassus ◽  
Order Complexes ◽  
Proliferating Cell ◽  
Lagging Strand

ABSTRACT In the ciliate Euplotes crassus, millions of new telomeres are synthesized by telomerase and polymerase α-primase during macronuclear development in mated cells. Concomitant with de novo telomere formation, telomerase assembles into higher-order complexes of 550 kDa, 1,600 kDa, and 5 MDa. We show here that telomerase is physically associated with the lagging-strand replication machinery in these complexes. Antibodies against DNA primase precipitated telomerase activity from all three complexes from mated cells but not the 280-kDa telomerase complex from vegetatively growing cells. Moreover, when telomerase was affinity purified, primase copurified with enzyme from mated cells but not with the 280-kDa vegetative complex. Thus, the association of telomerase and primase is developmentally regulated. Intriguingly, PCNA (proliferating cell nuclear antigen) was also found in the 5-MDa complex from mated cells. We therefore speculate that this complex is a complete telomere synthesis machine, while the smaller complexes are assembly intermediates. The physical association of telomerase and primase explains the coordinate regulation of telomeric G- and C-strand synthesis and the efficiency of telomere addition in E. crassus.

scholarly journals The Yeast PCNA Unloader Elg1 RFC-Like Complex Plays a Role in Eliciting the DNA Damage Checkpoint

mBio ◽  
2019 ◽  
Vol 10 (3) ◽  
Author(s):  
Soumitra Sau ◽  
Batia Liefshitz ◽  
Martin Kupiec
Keyword(s):  
Dna Damage ◽  
Dna Replication ◽  
Cellular Response ◽  
Genome Stability ◽  
Adaptor Proteins ◽  
Nuclear Antigen ◽  
Dna Damage Checkpoint ◽  
Activation Process ◽  
Checkpoint Activation ◽  
Dna Replication And Repair

ABSTRACT The PCNA (proliferating cell nuclear antigen) ring plays central roles during DNA replication and repair. The yeast Elg1 RFC-like complex (RLC) is the principal unloader of chromatin-bound PCNA and thus plays a central role in maintaining genome stability. Here we identify a role for Elg1 in the unloading of PCNA during DNA damage. Using DNA damage checkpoint (DC)-inducible and replication checkpoint (RC)-inducible strains, we show that Elg1 is essential for eliciting the signal in the DC branch. In the absence of Elg1 activity, the Rad9 (53BP1) and Dpb11 (TopBP1) adaptor proteins are recruited but fail to be phosphorylated by Mec1 (ATR), resulting in a lack of checkpoint activation. The chromatin immunoprecipitation of PCNA at the Lac operator sites reveals that accumulated local PCNA influences the checkpoint activation process in elg1 mutants. Our data suggest that Elg1 participates in a mechanism that may coordinate PCNA unloading during DNA repair with DNA damage checkpoint induction. IMPORTANCE The Elg1protein forms an RFC-like complex in charge of unloading PCNA from chromatin during DNA replication and repair. Mutations in the ELG1 gene caused genomic instability in all organisms tested and cancer in mammals. Here we show that Elg1 plays a role in the induction of the DNA damage checkpoint, a cellular response to DNA damage. We show that this defect is due to a defect in the signal amplification process during induction. Thus, cells coordinate the cell's response and the PCNA unloading through the activity of Elg1.

scholarly journals Visualization of replication initiation and elongation in Drosophila

2002 ◽  
Vol 159 (2) ◽  
pp. 225-236 ◽  
Author(s):  
Julie M. Claycomb ◽  
David M. MacAlpine ◽  
James G. Evans ◽  
Stephen P. Bell ◽  
Terry L. Orr-Weaver
Keyword(s):  
Dna Replication ◽  
Origin Recognition Complex ◽  
Developmental Stages ◽  
Replication Initiation ◽  
Nuclear Antigen ◽  
Minichromosome Maintenance ◽  
Egg Chamber ◽  
Two Phases ◽  
Replication Factors

Chorion gene amplification in the ovaries of Drosophila melanogaster is a powerful system for the study of metazoan DNA replication in vivo. Using a combination of high-resolution confocal and deconvolution microscopy and quantitative realtime PCR, we found that initiation and elongation occur during separate developmental stages, thus permitting analysis of these two phases of replication in vivo. Bromodeoxyuridine, origin recognition complex, and the elongation factors minichromosome maintenance proteins (MCM)2–7 and proliferating cell nuclear antigen were precisely localized, and the DNA copy number along the third chromosome chorion amplicon was quantified during multiple developmental stages. These studies revealed that initiation takes place during stages 10B and 11 of egg chamber development, whereas only elongation of existing replication forks occurs during egg chamber stages 12 and 13. The ability to distinguish initiation from elongation makes this an outstanding model to decipher the roles of various replication factors during metazoan DNA replication. We utilized this system to demonstrate that the pre–replication complex component, double-parked protein/cell division cycle 10–dependent transcript 1, is not only necessary for proper MCM2–7 localization, but, unexpectedly, is present during elongation.

scholarly journals Oxidative DNA Damage Bypass in Arabidopsis thaliana Requires DNA Polymerase λ and Proliferating Cell Nuclear Antigen 2

2011 ◽  
Vol 23 (2) ◽  
pp. 806-822 ◽  
Author(s):  
Alessandra Amoroso ◽  
Lorenzo Concia ◽  
Caterina Maggio ◽  
Cécile Raynaud ◽  
Catherine Bergounioux ◽  
...  
Keyword(s):  
Dna Damage ◽  
Arabidopsis Thaliana ◽  
Dna Polymerase ◽  
Proliferating Cell Nuclear Antigen ◽  
Oxidative Dna Damage ◽  
Nuclear Antigen ◽  
Dna Polymerase Λ ◽  
Proliferating Cell
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