scholarly journals Author response: Translesion polymerase kappa-dependent DNA synthesis underlies replication fork recovery

2018 ◽  
Author(s):  
Peter Tonzi ◽  
Yandong Yin ◽  
Chelsea Wei Ting Lee ◽  
Eli Rothenberg ◽  
Tony T Huang
Keyword(s):  
Dna Synthesis ◽  
Replication Fork ◽  
Author Response

Replication fork density increases during DNA synthesis in X. laevis egg extracts11Edited by M. Yaniv

2000 ◽  
Vol 300 (5) ◽  
pp. 1133-1142 ◽  
Author(s):  
J Herrick ◽  
P Stanislawski ◽  
O Hyrien ◽  
A Bensimon
Keyword(s):  
Dna Synthesis ◽  
Replication Fork

scholarly journals Enhanced H2AX Phosphorylation, DNA Replication Fork Arrest, and Cell Death in the Absence of Chk1

2010 ◽  
Vol 21 (5) ◽  
pp. 739-752 ◽  
Author(s):  
Mary E. Gagou ◽  
Pedro Zuazua-Villar ◽  
Mark Meuth
Keyword(s):  
Dna Replication ◽  
Dna Synthesis ◽  
Replication Fork ◽  
Brdu Incorporation ◽  
H2ax Phosphorylation ◽  
Direct Role ◽  
Γh2ax Foci ◽  
Dna Replication Stress ◽  
Sw480 Cells ◽  
Replication Fork Arrest

H2AX phosphorylation at serine 139 (γH2AX) is a sensitive indicator of both DNA damage and DNA replication stress. Here we show that γH2AX formation is greatly enhanced in response to replication inhibitors but not ionizing radiation in HCT116 or SW480 cells depleted of Chk1. Although H2AX phosphorylation precedes the induction of apoptosis in such cells, our results suggest that cells containing γH2AX are not committed to death. γH2AX foci in these cells largely colocalize with RPA foci and their formation is dependent upon the essential replication helicase cofactor Cdc45, suggesting that H2AX phosphorylation occurs at sites of stalled forks. However Chk1-depleted cells released from replication inhibitors retain γH2AX foci and do not appear to resume replicative DNA synthesis. BrdU incorporation only occurs in a minority of Chk1-depleted cells containing γH2AX foci after release from thymidine arrest and, in cells incorporating BrdU, DNA synthesis does not occur at sites of γH2AX foci. Furthermore activated ATM and Chk2 persist in these cells. We propose that the γH2AX foci in Chk1-depleted cells may represent sites of persistent replication fork damage or abandonment that are unable to resume DNA synthesis but do not play a direct role in the Chk1 suppressed death pathway.

scholarly journals CMG–Pol epsilon dynamics suggests a mechanism for the establishment of leading-strand synthesis in the eukaryotic replisome

2017 ◽  
Vol 114 (16) ◽  
pp. 4141-4146 ◽  
Author(s):  
Jin Chuan Zhou ◽  
Agnieszka Janska ◽  
Panchali Goswami ◽  
Ludovic Renault ◽  
Ferdos Abid Ali ◽  
...  
Keyword(s):  
Dna Synthesis ◽  
Single Particle ◽  
Replication Fork ◽  
Genome Duplication ◽  
Chromosome Replication ◽  
Dna Unwinding ◽  
Conformational Switch ◽  
Leading Strand ◽  
Dna Template

The replisome unwinds and synthesizes DNA for genome duplication. In eukaryotes, the Cdc45–MCM–GINS (CMG) helicase and the leading-strand polymerase, Pol epsilon, form a stable assembly. The mechanism for coupling DNA unwinding with synthesis is starting to be elucidated, however the architecture and dynamics of the replication fork remain only partially understood, preventing a molecular understanding of chromosome replication. To address this issue, we conducted a systematic single-particle EM study on multiple permutations of the reconstituted CMG–Pol epsilon assembly. Pol epsilon contains two flexibly tethered lobes. The noncatalytic lobe is anchored to the motor of the helicase, whereas the polymerization domain extends toward the side of the helicase. We observe two alternate configurations of the DNA synthesis domain in the CMG-bound Pol epsilon. We propose that this conformational switch might control DNA template engagement and release, modulating replisome progression.

Uracil recognition by archaeal family B DNA polymerases

2003 ◽  
Vol 31 (3) ◽  
pp. 699-702 ◽  
Author(s):  
B.A. Connolly ◽  
M.J. Fogg ◽  
G. Shuttleworth ◽  
B.T. Wilson
Keyword(s):  
Dna Synthesis ◽  
Protein Interactions ◽  
Replication Fork ◽  
Dna Polymerases ◽  
Structural Basis ◽  
Dna Glycosylases ◽  
Protein Protein Interactions ◽  
Sensing Mechanism ◽  
Uridine Triphosphate

Archaeal family-B DNA polymerases possess a novel uracil-sensing mechanism. A specialized pocket scans the template, ahead of the replication fork, for the presence of uracil; on encountering this base, DNA synthesis is stalled. The structural basis for uracil recognition by polymerases is described and compared with other uracil-recognizing enzymes (uridine-triphosphate pyrophophatases and uracil-DNA glycosylases). Remarkably, protein–protein interactions between all three archaeal uracil sensors are observed; possibly the enzymes co-operate to efficiently eliminate uracil from archaeal genomes.

scholarly journals Visualization of Altered Replication Dynamics after DNA Damage in Human Cells

2004 ◽  
Vol 279 (19) ◽  
pp. 20067-20075 ◽  
Author(s):  
Catherine J. Merrick ◽  
Dean Jackson ◽  
John F. X. Diffley
Keyword(s):  
Dna Damage ◽  
Dna Synthesis ◽  
Replication Fork ◽  
S Phase ◽  
High Rate ◽  
Yeast Cells ◽  
Origin Firing ◽  
Large Numbers ◽  
Dependent Inhibition ◽  
Fork Stalling

Eukaryotic cells respond to DNA damage within the S phase by activating an intra-S checkpoint: a response that includes reducing the rate of DNA synthesis. In yeast cells this can occur via checkpoint-dependent inhibition of origin firing and stabilization of ongoing forks, together with a checkpoint-independent slowing of fork movement. In higher eukaryotes, however, the mechanism by which DNA synthesis is reduced is less clear. We have developed strategies based on DNA fiber labeling that allow the quantitative assessment of rates of replication fork movement, origin firing, and fork stalling throughout the genome by examining large numbers of individually labeled replication forks. We show that exposing S phase cells to ionizing radiation induces a transient block to origin firing but does not affect fork rate or fork stalling. Alkylation damage by methyl methane sulfonate causes a slowing of fork movement and a high rate of fork stalling, in addition to inducing a block to new origin firing. Nucleotide depletion by hydroxyurea also reduces replication fork rate and increases stalling; moreover, in contrast to a recent report, we show that hydroxyurea induces a strong block to new origin firing. The DNA fiber labeling strategy provides a powerful new approach to analyze the dynamics of DNA replication in a perturbed S phase.

scholarly journals Replication Fork Bypass of a Pyrimidine Dimer Blocking Leading Strand DNA Synthesis

1997 ◽  
Vol 272 (21) ◽  
pp. 13945-13954 ◽  
Author(s):  
Marila Cordeiro-Stone ◽  
Liubov S. Zaritskaya ◽  
Laura K. Price ◽  
William K. Kaufmann
Keyword(s):  
Dna Synthesis ◽  
Replication Fork ◽  
Pyrimidine Dimer ◽  
Leading Strand
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