• The results are shown in the open access journal Frontiers in Cell and Developmental Biology ( 'Fidelity of a bacterial DNA polymerase in microgravity, a model for human health in space' ). (nanowerk.com)
  • Rosenstein and his supervisor and coauthor, Prof Virginia K. Walker, here show for the first time that the error rate of a DNA polymerase derived from E. coli bacteria is consistently higher under microgravity. (nanowerk.com)
  • As expected, accuracy also depended on whether the DNA polymerase retains a 'proofreading' functionality, which verifies (and if necessary removes) any mismatched nucleotides: a version of the enzyme whose proofreading had been inactivated due to mutations had a roughly 50% greater substitution rate. (nanowerk.com)
  • One mechanism by which high-fidelity DNA polymerases maintain replication accuracy involves stalling of the polymerase in response to covalent incorporation of mismatched base pairs, thereby favoring subsequent mismatch excision. (rcsb.org)
  • Our observations suggest four mechanisms that lead to mismatch-induced stalling of the polymerase. (rcsb.org)
  • In this work, we analyzed the ability of phi29 DNA polymerase to insert dUMP into DNA. (nih.gov)
  • Primer extension analysis showed that viral DNA polymerase incorporates dU opposite dA with a catalytic efficiency only 2-fold lower than that for dT. (nih.gov)
  • Using the phi29 DNA amplification system, we found that phi29 DNA polymerase is also able to carry out the extension of the dA:dUMP pair and replicate past uracil. (nih.gov)
  • Additionally, UDG and apurinic-apyrimidinic endonuclease treatment of viral DNA isolated from phi29-infected cells revealed that uracil residues arise in phi29 DNA during replication, probably as a result of misincorporation of dUMP by the phi29 DNA polymerase. (nih.gov)
  • Primer will be removed by a 5' to 3' exonuclease activity in DNA polymerase I. (kipdf.com)
  • Two metal ions (Mg or Mn) are crucial to the action of DNA polymerase. (kipdf.com)
  • Proposed structure of DNA pol III holoenzyme (900 kD, 10 subunits, asymmetric dimer, one for leading, one for lagging strand (α is polymerase, ε is proofreading 3'Æ5' exonuclease, β2 and δ2 for processivity). (kipdf.com)
  • This published article-format thesis focusses on a recently discovered primase-polymerase, and member of the archaeo-eukaryotic primase (AEP) superfamily, involved in DNA damage tolerance, known as PrimPol. (figshare.com)
  • The replisome contains activities that separate the strands and hold them apart for synthesis by the replisome version of DNA polymerase, called DNA polymerase III in bacteria. (blogspot.com)
  • Deoxyribonucleic Acid (DNA) Recall that the replisome contains a DNA polymerase III holoenzyme dimer with two core complexes that can catalyze polymerization. (blogspot.com)
  • Each primer is extended from its 3′ end by DNA polymerase I to form an Okazaki fragment, as shown in the Figure. (blogspot.com)
  • The use of short RNA primers gets around the limitation imposed by the mechanism of DNA polymerase, namely, that it cannot initiate DNA synthesis de novo . (blogspot.com)
  • The primers are synthesized by a DNA dependent RNA polymerase enzyme called primase-the product of the dna G gene in E. coli . (blogspot.com)
  • The primosome, along with DNA polymerase III, is part of the replisome. (blogspot.com)
  • DNA polymerase III catalyzes synthesis of DNA in the 5′ → 3′ direction by extending each short RNA primer. (blogspot.com)
  • The steps are carried out by the combined action of DNA polymerase I and DNA ligase. (blogspot.com)
  • DNA replication demands extraordinary specificity and efficiency of catalysis from a DNA polymerase. (utexas.edu)
  • An important study of T7 DNA polymerase performed by Tsai and Johnson using a conformationally sensitive fluorophore (CSF) characterized a conformational change directly and presented a new paradigm for nucleotide selectivity. (utexas.edu)
  • Yellow crystals of CSF-labeled T7 DNA polymerase with DNA and correct nucleotide (closed complex), incorrect nucleotide (misaligned complex) or no nucleotide (open complex) were grown to good size and diffracted to 3 Å during X-ray data collection. (utexas.edu)
  • The virus transfers its DNA to initiate replication and uses its own DNA polymerase (enzyme that synthesizes DNA) and histones, but overall, it relies on the host to complete the process. (eurekalert.org)
  • The results of an evolutionary analysis done by the authors suggest that in the evolution tree, the Medusavirus DNA polymerase lies at the origin of the DNA polymerase found in eukaryotes. (eurekalert.org)
  • As one of the authors, Dr Genki Yoshikwa from Kyoto University, puts it, this could mean that our DNA polymerase "probably originated from Medusavirus or one of its relatives. (eurekalert.org)
  • This protein was found to also interact with DNA polymerase alpha/primase and mediate the phosphorylation of the large p180 subunit, which suggests a regulatory role in DNA replication during the S-phase of the cell cycle. (cancerindex.org)
  • We identify an important role for DDX5 in G 1 -S-phase progression where it directly regulates DNA replication factor expression by promoting the recruitment of RNA polymerase II to E2F-regulated gene promoters. (aacrjournals.org)
  • The core contains circular double-stranded DNA and DNA polymerase, and it replicates within the nuclei of infected hepatocytes. (msdmanuals.com)
  • We find that this type of non-canonical fork convergence in fission yeast is prone to trigger deletions between repetitive DNA sequences via a mechanism we call Inter-Fork Strand Annealing (IFSA) that depends on the recombination proteins Rad52, Exo1 and Mus81, and is countered by the FANCM-related DNA helicase Fml1. (elifesciences.org)
  • Equivalent processes in vertebrates involve actions of two distinct proteins, suggesting that Dmt represents an intermediate stage of protein evolution. (sciencedaily.com)
  • Regardless of organism, replication origins are unique DNA segments with multiple short repeats, recognized by multimeric origin-binding proteins, and usually contain an A-T rich stretch. (kipdf.com)
  • Post-translational modifications of histone proteins play a pivotal role in DNA packaging and regulation of genome functions. (sdbonline.org)
  • In mice, rapamycin treatment increases expression of histone proteins and Wdfy3 transcription, and alters chromatin organisation in the small intestine, suggesting the mTORC1-histone axis is at least partially conserved in mammals and may offer new targets for anti-ageing interventions. (sdbonline.org)
  • In the second paper, evidence is presented to suggest that PrimPol's activity is regulated by single-strand binding proteins, required due to the enzyme's error-prone nature. (figshare.com)
  • Recent breakthroughs have uncovered more and more DNA replication licensing machinery proteins (ORC, Cdc6, Cdt1, geminin, etc.) functioning in other cell cycle events, including centrosome replication, mitotic events, transcription and so on. (intechopen.com)
  • It is interesting because, unlike most viruses, it contains genes that encode for proteins involved in DNA packaging. (eurekalert.org)
  • The Medusavirus has a full set of histones, which are proteins that have evolved to keep the DNA folded inside the nucleus and regulate gene expression. (eurekalert.org)
  • Whenever genomic lesions are detected during DNA synthesis, they are coated by the single strand DNA binding protein complex, called Replication Protein A, leading to the activation of canonical checkpoint proteins like ATR, Chk1 and p53. (nii.res.in)
  • Human genome codes for many other single strand DNA binding proteins and we are testing if novel mechanisms of checkpoint activation exist that do not require Replication Protein A. If such mechanisms exist we would like to understand which factors provide the role of DNA binding, how checkpoint proteins like Chk1 and p53 are activated and how signal transduction pathway stalls the cell cycle and DNA replication. (nii.res.in)
  • It has been observed that some replication proteins localize to the centrosome suggesting their role in regulation of centrosome biogenesis. (nii.res.in)
  • DDX5 is required for cell proliferation by controlling the transcription of genes expressing DNA replication proteins in cancer cells in which the DDX5 locus is amplified, and this has uncovered a dependence on DDX5 for cell proliferation. (aacrjournals.org)
  • They facilitate many cellular functions, from DNA replication to molecular motion, energy production, and even the production of other proteins. (lu.se)
  • So-called DNA polymerases are essential enzymes that copy and repair DNA. (nanowerk.com)
  • Here we show that DNA polymerases derived from the bacterium E. coli are considerably more prone to errors under microgravity, such as occurs in space. (nanowerk.com)
  • If DNA polymerases become less accurate in space, the already high mutation rate will increase even further as DNA is copied, with cancer as one of the potential consequences for astronauts. (nanowerk.com)
  • We have shown that DNA polymerases similar to those found in mitochondria - the cell's powerhouses - make more errors in microgravity. (nanowerk.com)
  • Some polymerases retain a "short-term memory" of replication errors, responding to mismatches up to four base pairs in from the primer terminus. (rcsb.org)
  • At the heart of the replisome lie the replicative DNA polymerases which catalyse synthesis of daughter DNA strands with astonishing accuracy and efficiency. (figshare.com)
  • DNA polymerases catalyze chain elongation exclusively in the 5′ → 3′ direction. (blogspot.com)
  • The three-dimensional crystal structure of the DnaG catalytic domain revealed its folding and active site are distinct from the well studied polymerases, suggesting that it may employ a novel enzyme mechanism. (blogspot.com)
  • Previous studies on several DNA polymerases suggested that a rate-limiting conformational change preceding chemistry accounts for the high specificity following the induced fit mechanism. (utexas.edu)
  • In S. cerevisiae, more commonly budding yeast, Rad30 (pol η), Rev1, and Rev3/Rev7 (pol ζ) are the key polymerases in the TLS pathway, forming the cellular machinery that allows replication to bypass lesions in DNA. (tufts.edu)
  • Work from our lab has shown that deletion of only one or two of the TLS polymerases had CAG fragility levels similar to those of wild-type strains, suggesting that perhaps the polymerases can compensate for one another when one or more is missing. (tufts.edu)
  • AsdA is estimated to be about 540 nucleotides long, and represents the complementary strand to that encoding DnaA, a protein that plays a central role in the initiation of DNA replication and hence cellular division. (wikipedia.org)
  • In this chapter, we mainly discuss the coordination regulations between DNA replication initiation and other cell cycle events that ensure genomic integrity. (intechopen.com)
  • DNA replication occurs once and only once per cell cycle mainly regulated by DNA replication initiation factors in eukaryotic cells. (intechopen.com)
  • The pre-replication complex (pre-RC) assembly or the DNA replication licensing is the first step in DNA replication initiation, characterized by the sequential recruitment of ORCs, Cdc6, Cdt1 and MCMs to the DNA replication origins to form the pre-RC at the end of mitosis ( Bell and Dutta 2002 ). (intechopen.com)
  • Here we have mapped sites of DNA replication initiation across the T. cruzi genome using Marker Frequency Analysis, which has previously only been deployed in two related trypanosomatids. (biomedcentral.com)
  • It is known that replication factors are downregulated during stress and we have observed that cullin 4-based ubiquitin ligase mediate the proteolysis of Mcm10, a protein essential for the initiation and elongation phases of DNA replication. (nii.res.in)
  • Combining time-lapse fluorescent microscopy, mathematical modeling, molecular genetics and biochemical approaches, Liao and Rust were able to track DNA replication initiation, completion, and failures in bacteria exposed to different illumination patterns, including constant light , normal light/dark cycles and cycles with unexpected periods of darkness. (phys.org)
  • Further, we did not detect elongation from a displacement-loop or analogue of 7S DNA, suggesting a clear difference from human mtDNA in regard to the site(s) of replication initiation. (escholarship.org)
  • The ORC-Cdc6 complex (product 1) assembles in step 1 around origin DNA and with the help of another replication initiator protein, Cdt1, it recruits the Mcm2-7 hexamer to the origin in step 2. (nature.com)
  • Research has identified a double function for the Drosophila Dmt protein in both establishing and maintaining cohesion whereby identical chromatids pair during DNA replication. (sciencedaily.com)
  • This typically occurs during DNA replication, and in vertebrates requires the cohesin-associating protein sororin. (sciencedaily.com)
  • Protein p56 encoded by the Bacillus subtilis phage phi29 inhibits host uracil-DNA glycosylase (UDG) activity. (nih.gov)
  • On the other hand, the action of UDG on uracil-containing phi29 DNA impaired in vitro viral DNA replication, which was prevented by the presence of protein p56. (nih.gov)
  • Furthermore, transfection activity of uracil-containing phi29 DNA was significantly higher in cells that constitutively synthesized p56 than in cells lacking this protein. (nih.gov)
  • Thus, our data support a model in which protein p56 ensures an efficient viral DNA replication, preventing the deleterious effect caused by UDG when it eliminates uracil residues present in the phi29 genome. (nih.gov)
  • The fifth presented paper identifies the molecular basis for PrimPol's interaction with replication protein A (RPA). (figshare.com)
  • The precise regulations of pre-RC protein levels and assembly are effective ways to prevent reassembly of de novo MCM2-7 onto the replicated origins to re-license and re-replicate the genomic DNA in the subsequent phases of the same cell cycle ( Figure 1) . (intechopen.com)
  • As originally proposed in 1963, cells rely on two genetic elements to duplicate their genome: the replicator, a DNA region where replication begins (now named the replication origin), and the initiator, a protein or a protein complex that recognizes the replicator [ 1 ]. (biomedcentral.com)
  • However, the replisome can be stalled by depletion of nucleotide pools or barriers on the template, such as DNA damage, secondary structures or protein complexes [ 11 ]. (biomedcentral.com)
  • Finally, the video describes some of the many ways in which yeast cells are put to work in modern scientific research, including protein purification and the study of DNA repair mechanisms and other cellular processes related to Alzheimer's and Parkinson's diseases. (jove.com)
  • Huntingtin contains a few domains that suggest particular functions, including WW domains and caspase cleavage sites ( 7 , 8 ), but the function of the protein remains unknown. (jci.org)
  • Western blot analysis of HD brain tissue shows full-length huntingtin protein in the nuclear fraction as well as abundant immunopositive bands at lower molecular weight, suggesting proteolytic products in the nucleus. (jci.org)
  • The experiments followed decades of scientists' skepticism about whether genetic material was composed of protein or DNA. (asu.edu)
  • Regardless of its precise form, collapse renders the fork incompetent for further DNA synthesis. (elifesciences.org)
  • DNA synthesis can be impeded by collisions between the DNA replication machinery and co-transcriptional R-loops leading to a major source of genomic instability in cancer cells. (leica-microsystems.com)
  • The work presented here builds on the initial characterisation of the enzyme, which identified potential roles in the bypass of DNA damage through translesion synthesis (TLS) and repriming of replication. (figshare.com)
  • Since the two strands of DNA are antiparallel, synthesis using one template strand occurs in the same direction as fork movement, but synthesis using the other template strand occurs in the direction opposite fork movement. (blogspot.com)
  • This limitation presents no difficulty for leading-strand synthesis since once DNA synthesis is under way nucleotides are continuously added to a growing chain. (blogspot.com)
  • About once every second, primase catalyzes the synthesis of a short RNA primer using this single-stranded DNA as a template. (blogspot.com)
  • The reaction proceeds in three steps: removal of the RNA primer, synthesis of replacement DNA, and sealing of the adjacent DNA fragments. (blogspot.com)
  • Indeed, a number of agents currently used in cancer treatment are known to target DNA synthesis. (aacrjournals.org)
  • Overall these results indicate that mtDNA synthesis in C. elegans does not conform to any previously documented metazoan mtDNA replication mechanism, but instead are strongly suggestive of rolling circle replication, as employed by bacteriophages. (escholarship.org)
  • At the same time, the intensity of the DNA total synthesis is higher in old spleens than in adult ones. (karger.com)
  • Replication may be categorized into immediate early, delayed early, and late gene expression based on time of synthesis after infection. (medscape.com)
  • Investigating the mechanism of synthetic lethality, we reveal that CHK1 inhibition in IGF-1R depleted or inhibited cells further downregulated RRM2, reduced dNTP supply and profoundly delayed replication fork progression. (nature.com)
  • The results illuminate the molecular mechanism of a critical biochemical step in the licensing of eukaryotic replication origins. (nature.com)
  • Unknown until now was whether the natural DNA copying mechanism is also affected by weightless conditions in space. (nanowerk.com)
  • In previous studies, we suggested that this inhibition is likely a defense mechanism developed by phage phi29 to prevent the action of UDG if uracilation occurs in DNA either from deamination of cytosine or the incorporation of dUMP during viral DNA replication. (nih.gov)
  • 2. A mechanism is required to separate the strands locally for replication. (kipdf.com)
  • Using biophysical, biochemical, and cellular approaches, this paper identifies the mechanism by which PrimPol is recruited to reprime replication. (figshare.com)
  • The overall mechanism of DNA replication is called semidiscontinuous to emphasize the different mechanisms for replicating each strand. (blogspot.com)
  • Therefore, we are trying to understand the independent mechanism by which mammalian cells effectively inhibit the replication machinery during stress preventing it from drifting towards a catastrophic path of genomic instability. (nii.res.in)
  • As several components of the metazoan mitochondrial DNA replisome are likely phage-derived, these findings raise the possibility that the rolling circle mtDNA replication mechanism may be ancestral among metazoans. (escholarship.org)
  • Their model suggested a replication mechanism, later termed semi-conservative replication, in which parental DNA strands separated and served as templates for the replication of new daughter strands. (asu.edu)
  • Helicase for unwinding For DNA duplex to replicate, the two strands must be separated from each other,at least locally. (kipdf.com)
  • During DNA replication, a molecular machine called a replisome forms at the replication fork where the two strands of DNA are separating. (blogspot.com)
  • The complex has two sliding clamps that bind the complex to the strands of DNA so that DNA replication is highly processive. (blogspot.com)
  • Retention of labeled DNA strands may be attributed to the ability of stem cells to retain the parental DNA strand during asymmetric cell division ( Cairns, 1975 ) or to quiescence of the stem cell population such that the DNA label is not diluted by frequent cell divisions ( Klein and Simons, 2011 ). (frontiersin.org)
  • During rapid mammary growth in the mouse, label retaining epithelial cells (LREC) appear to retain label by asymmetric distribution of DNA strands, as evidenced by a rapid proliferation index of the LREC ( Smith, 2005 ). (frontiersin.org)
  • In 1953, James Watson and Francis Crick proposed that DNA was composed of two helical strands that wound together in a coil. (asu.edu)
  • They also made a longer L-aTNA with a nucleobase sequence that complemented the sequences of the fragments, similar to how DNA strands match up. (astrobiology.com)
  • Capsid deformation leads to displacement of water molecules hydrating the DNA and interhelical sliding, occurring with compression of the packaged DNA strands. (lu.se)
  • In the fluid-like state, the interstrand DNA-DNA friction of the encapsidated genome is significantly reduced due to an increase in distance between packaged DNA strands occurring with local DNA disordering. (lu.se)
  • Between 1953 and 1957, before the Meselson-Stahl experiment verified semi-conservative replication of DNA, scientists debated how DNA replicated. (asu.edu)
  • Collision between replication and transcription is considered especially problematic, as each are catalyzed by large multiprotein machines, and can occur co-directionally, when the replication fork and transcription machinery are moving in the same direction, or on the leading strand and is head-on, when the fork and transcription are moving towards each other. (biomedcentral.com)
  • Accumulated evidence suggests head-on collisions have a more pronounced effect on genome instability, perhaps because more extensive changes to the machinery and template are needed to resolve such conflicts [ 12 ], some of which might result in increased single-stranded DNA gaps and DNA double strand break (DSB) formation [ 13 ]. (biomedcentral.com)
  • Emerging evidences suggest that microRNA target genes that regulate DNA replication and cell cycle progression and we aim to determine how microRNA regulate the DNA replication machinery as cell progresses from one phase to the next. (nii.res.in)
  • the replication machinery disassembles, leaving cells with incomplete chromosomes. (phys.org)
  • If the clock is in the wrong state, it's the difference between completing the replication event, or the replication machinery falling apart completely. (phys.org)
  • A dimerized coiled-coil domain and an adjoining part of geminin interact with two sites on Cdt1 for replication inhibition. (nii.res.in)
  • oriC: origin of replication in E. coli: OriC 245 bp (3 13-nt and dnaA binding sites) in 4.8 m bp genome. (kipdf.com)
  • Genome replication is responsible for accurate transmission of genetic information through cell division cycles. (biomedcentral.com)
  • But DNA replication takes three to four hours to replicate the entire genome, so there's a fundamental need to predict the future. (phys.org)
  • Francis Sellers Collins helped lead the International Human Genome Sequencing Consortium, which helped describe the DNA sequence of the human genome by 2001, and he helped develop technologies used in molecular genetics while working in the US in the twentieth and twenty-first centuries. (asu.edu)
  • It is the largest (220 nm in diameter) and most complex herpesvirus, with a 235,000 double-stranded DNA genome. (medscape.com)
  • This transition is induced by increasing the temperature (which affects DNA bending stress and packing defects) or by varying external ionic conditions (which affects DNA-DNA repulsive interactions and overall genome stress in the capsid). (lu.se)
  • These AFM observations suggest that dynamics of DNA ejection can be affected by a transition in mobility of the encapsidated genome. (lu.se)
  • First, given evidence that IGFs regulate the response to IR, we also found evidence that IGF-1R depletion induced endogenous DNA lesions marked by γH2AX foci in prostate cancer cells [ 10 ]. (nature.com)
  • TSPyV DNA loads can be high, especially in blood (up to 10 8 viral copies/mL), months before the appearance of typical trichodysplasia spinulosa skin lesions ( 4 ). (cdc.gov)
  • Nevertheless, these enzymes are prone to stalling upon encountering DNA damage lesions and secondary structures. (figshare.com)
  • Chapter 4 focusses on the development and use of a gel-based fluorescent primase assay to assess PrimPol's ability to reprime downstream of DNA damage lesions and secondary structures. (figshare.com)
  • This so-called recombination-dependent replication (RDR) helps ensure that DNA is fully replicated prior to sister chromatid segregation, thereby avoiding mitotic catastrophes. (elifesciences.org)
  • Bile salt exposure is found to increase GC to AT transition mutations and also to induce genes of the OxyR and SoxRS regulons suggesting further that bile salts specifically cause oxidative DNA damage. (wikipedia.org)
  • Several of these genes, the TREX1 , RNASEH2A , RNASEH2B , and RNASEH2C genes, provide instructions for making nucleases, which are enzymes that help break down molecules of DNA and its chemical cousin RNA when they are no longer needed. (medlineplus.gov)
  • Modules within the network provide insight into cellular and genomic structure and function, such as genes functioning in distinct cellular compartments and DNA replication. (biorxiv.org)
  • The putative origins identified in T. cruzi show a notable enrichment of GC content, a preferential position at subtelomeric regions, coinciding with genes transcribed towards the telomeres, and a pronounced enrichment within coding DNA sequences, most notably in genes from the Dispersed Gene Family 1 (DGF-1). (biomedcentral.com)
  • These findings suggest a scenario where collisions between DNA replication and transcription are frequent, leading to increased genetic variability, as seen by the increase SNP levels at chromosome subtelomeres and in DGF-1 genes containing putative origins. (biomedcentral.com)
  • In 1951 and 1952, Alfred Hershey and Martha Chase conducted a series of experiments at the Carnegie Institute of Washington in Cold Spring Harbor, New York, that verified genes were made of deoxyribonucleic acid, or DNA. (asu.edu)
  • Epigenetic information can be transmitted by several different molecular mechanisms, which include but are not limited to DNA methylation and histone post-translational modifications (PTMs). (plos.org)
  • Our results support the use of DNA label retention to identify MaSC and also provide a molecular profile and novel candidate markers for these cells. (frontiersin.org)
  • This can be substantiated by the slowing down of transformation of old spleen 3 H-labeled DNA with low molecular weight to that with high molecular weight as labeling time increases. (karger.com)
  • The Origin Recognition Complex (ORC) binds to sites in chromosomes to specify the location of origins of DNA replication. (nature.com)
  • In the budding yeast Saccharomyces cerevisiae , there are over 400 origins of DNA replication located on 16 chromosomes and they can function as autonomously replicating sequences (ARSs) when inserted into a plasmid 19 . (nature.com)
  • Although chromosomes were long assumed to play rather a passive role during the cell division process, recent evidence suggests that chromosomes play a much more active role in the process of their own segregation. (europa.eu)
  • DNA replication cycles are tied to the circadian clock, and interruptions can lead to incomplete chromosomes. (phys.org)
  • A new study from the University of Chicago has found that the photosynthetic bacterium Synechococcus elongatus uses a circadian clock to precisely time DNA replication, and that interrupting this circadian rhythm prevents replication from completing and leaves chromosomes unfinished overnight. (phys.org)
  • Maybe this is a major driving force in the evolution of the circadian clock-you want to avoid damaged DNA and unfinished chromosomes, so the clock has evolved multiple times in history to prevent those things from happening. (phys.org)
  • Eukaryotic DNA replication initiates at multiple origin sites along each chromosome and terminates when replication forks (RFs) from adjacent origins converge. (elifesciences.org)
  • In all other eukaryotes, clear consensus sequences for origins are elusive, perhaps indicating there are no cis elements to initiate replication in most of these cells and organisms. (biomedcentral.com)
  • According to the usage, origins have been classified as constitutive (fired at same position in different cells of a population), flexible (fired stochastically in different cells) and dormant (fired as consequence of replication stress) [ 5 ]. (biomedcentral.com)
  • Nagoya University scientists in Japan have demonstrated how DNA-like molecules could have come together as a precursor to the origins of life. (astrobiology.com)
  • These effects resulted in significant accumulation of unreplicated single-stranded DNA and increased cell death, indicative of replication catastrophe. (nature.com)
  • As the replication fork progresses, the parental DNA is unwound, and more and more single-stranded DNA becomes exposed. (blogspot.com)
  • Replication fork barriers are a commonly encountered problem, which can cause fork collapse and act as hotspots for replication termination. (elifesciences.org)
  • However, replication restart is relatively slow and, therefore, replication termination may frequently occur by an active fork converging on a collapsed fork. (elifesciences.org)
  • RDR can initiate from a collapsed fork where the DNA is either broken or remains intact. (elifesciences.org)
  • Using a sequential nucleoside analog incorporation assay, a high incidence of unidirectional replication fork movement is detected in testes-derived chromatin and DNA fibers. (sdbonline.org)
  • Biased fork movement coupled with a strand preference in histone incorporation would explain how asymmetric old and new H3 and H4 are established during replication. (sdbonline.org)
  • This is accomplished by making short pieces of RNA at the replication fork. (blogspot.com)
  • Since the replication fork advances at a rate of about 1000 nucleotides per second, one primer is synthesized for approximately every 1000 nucleotides that are incorporated. (blogspot.com)
  • We recently reported that genetic or pharmacological inhibition of insulin-like growth factor receptor (IGF-1R) slows DNA replication and induces replication stress by downregulating the regulatory subunit RRM2 of ribonucleotide reductase, perturbing deoxynucleotide triphosphate (dNTP) supply. (nature.com)
  • In this paper we showed that the ATP-dependent chromatin remodelling INO80 complex promotes resolution of R-loops to prevent replication-associated DNA damage in cancer cells. (leica-microsystems.com)
  • In some processes, chromatin modifications carry heritable regulatory information that is transmitted from mother to daughter cells, whereas in other cases, they are implicated in the execution of the information contained in the DNA sequence, or occur as a consequence of dynamic nuclear processes such as transcription. (plos.org)
  • Hat1 is implicated in chromatin assembly and DNA repair but its role in cell functions is not clearly elucidated. (sdbonline.org)
  • Archetypal patterns are found in nature, the theories of chromatin packing and DNA expression, and in the self-similar replication of fractals. (williamkingmuseum.org)
  • The first suggests that disruption of the inner nuclear membrane and the nuclear lamina causes disorganization of nuclear chromatin and gene expression, while the second proposes that the mechanical strength of the cell nucleus is disrupted when the nuclear lamina is weakened leading to structural and signaling defects in mechanically stressed tissue such as muscle and heart. (medscape.com)
  • Exposure of S. enterica to bile salts, such as sodium deoxycholate, induces the SOS DNA damage response indicating that in this organism bile salts cause DNA damage. (wikipedia.org)
  • MMC induces DNA damage to quiescent corneal keratocytes, which remains unrepaired, resulting in abnormal cell replication and gene transcription that leads to long-term effects on corneal repair. (molvis.org)
  • Mitomycin C (MMC) belongs to a family of anti-tumor quinolone antibiotics derived from Streptomyces caespitosus , and functions as a powerful bifunctional alkylating agent that induces DNA interstrand crosslinks (ICL). (molvis.org)
  • In order to restart replication, DNA damage tolerance mechanisms are required. (figshare.com)
  • Together, this work supports a role for PrimPol in repriming and restarting DNA replication following stalling at impediments, as well as identifying mechanisms involved in the recruitment and regulation of the enzyme. (figshare.com)
  • When mammalian cell experiences DNA damage, it activates checkpoint mechanisms to stall the progression of cell cycle and DNA replication. (nii.res.in)
  • Summing up, we are trying to understand the mechanisms by which microRNAs regulate mammalian cell cycle and DNA replication in normal and pathological conditions. (nii.res.in)
  • The pathogenic role of HBV in these disorders is unclear, but autoimmune mechanisms are suggested. (msdmanuals.com)
  • The Medusavirus is a nucleocytoplasmic large DNA virus, which belongs to a group of recently discovered eukaryotic viruses with large and complex double-stranded DNA (dsDNA) genomes. (eurekalert.org)
  • Cytomegalovirus (CMV) is a double-stranded DNA virus and is a member of the Herpesviridae family. (medscape.com)
  • 2) the two sister DNA molecules remain tightly associated with each other from the moment of DNA replication until the metaphase-anaphase transition of the subsequent mitosis. (europa.eu)
  • copying (replication) of cells' genetic material in preparation for cell division, DNA repair, cell death (apoptosis), and other processes. (medlineplus.gov)
  • Accurate cell division relies on the fact that the genetic information encoded in the DNA molecules is equally segregated into the two daughter cells. (europa.eu)
  • According to classic definitions, epigenetics refers to heritable differences between cells or organisms that occur without changes in DNA sequence, and do not depend on different external conditions [1] - [4] . (plos.org)
  • The majority is due to 'bad luck,' that is, random mutations arising during DNA replication in normal, noncancerous stem cells. (cdc.gov)
  • These results suggest a role for DNA replication in patterning epigenetic information in asymmetrically dividing cells in multicellular organisms. (sdbonline.org)
  • The left panel shows aborted replication activity in misaligned cells in the dark. (phys.org)
  • We applied an assay that measures the stability of maintenance of an episomal plasmid in human tissue culture cells to screen for new DNA replication factors. (aacrjournals.org)
  • Understanding how DNA replication is regulated in human cells can provide insight into cancer development and may reveal vulnerabilities that can be exploited therapeutically. (aacrjournals.org)
  • Our results show a novel role for DDX5 in cancer cell proliferation and suggest DDX5 as a therapeutic target in breast cancer treatment. (aacrjournals.org)
  • The S. cerevisiae ORC binds to specific DNA sequences throughout the cell cycle but becomes active only when it binds to the replication initiator Cdc6. (nature.com)
  • Here we report the cryo-EM structure at 3.3 Å resolution of the yeast ORC-Cdc6 bound to an 85-bp ARS1 origin DNA. (nature.com)
  • The structure reveals that Cdc6 contributes to origin DNA recognition via its winged helix domain (WHD) and its initiator-specific motif. (nature.com)
  • After origin firing, bidirectional replication forks travel until they reach termination sites. (biomedcentral.com)
  • It was suggested that the ERS signaling pathway also plays an active part in cancer progression [ 12 ]. (biomedcentral.com)
  • These studies furthered understanding of specific organ and tissue sites of virus replication at different phases of disease progression and were thus considered useful in studies designed to assess the efficacy of antiviral drugs. (who.int)
  • The RecBCD enzyme which functions in recombinational repair of DNA is also required for bile salt resistance. (wikipedia.org)
  • Furthermore, we have observed the effects of extending a mismatch up to six base pairs from the primer terminus and find that long-range distortions in the DNA transmit the presence of the mismatch back to the enzyme active site, suggesting the structural basis for the short-term memory of replication errors. (rcsb.org)
  • Ultraviolet Radiation Stress Triggers the Down-regulation of Essential Replication Factor Mcm10. (nii.res.in)
  • Collapsed forks can be rescued by homologous recombination, which restarts replication. (elifesciences.org)
  • The scientists' mission under these difficult conditions was to test whether the enzymes that copy DNA are as accurate under weightlessness as under earthbound conditions. (nanowerk.com)
  • Unlike RNA, however, XNA replication probably didn't require enzymes. (astrobiology.com)
  • These data suggest that the INO80 complex associates with the largest, most enriched, R-loop domains in the nucleus. (leica-microsystems.com)
  • With the Medusavirus, scientists discovered that DNA replication occurred in the nucleus of the host amoeba and observed evidence of exchange of genetic information between the host and the virus as they coevolved. (eurekalert.org)
  • 2. Nuclear transfer is a technique used to duplicate genetic material by creating an embryo through the transfer and fusion of a diploid cell in an enucleated female oocyte.2 Cloning has a broader meaning than nuclear transfer as it also involves gene replication and natural or induced embryo splitting (see Annex 1). (who.int)
  • The evidence suggests that circadian rhythms have evolved multiple times among different species, so there must be something very fundamental and important that's shared among these different species," said first author Yi Liao, a postdoctoral scholar in Rust's lab. (phys.org)
  • Replication of T4 phage DNA in E. coli, wild type vs. ligase mutant, with 3Hthymidine pulse labeling (when ung- E. coli mutant was used, >50% of newly labeled DNA was still in short pieces). (kipdf.com)
  • This question is of paramount importance for future space exploration, as the health of astronauts will depend on accurate DNA replication during cell division. (nanowerk.com)
  • More cell divisions reflect a higher risk as errors that occur naturally during the DNA replication process can contribute to the development of cancer. (scienceblogs.com)
  • DNA replication is a vital process of life and must be completed precisely during each cell cycle. (nii.res.in)
  • Aberrations in microRNA activity has been linked to loss of cell cycle and replication control and this has led to oncogenic functions (thereby called oncomirs) being ascribed to them. (nii.res.in)
  • The right panel shows continued replication in an aligned cell. (phys.org)
  • In an earlier study, we found that the anti-herpes antiviral drug, acyclovir, blocks HSV1 DNA replication , and reduces levels of beta-amyloid and tau caused by HSV1 infection of cell cultures. (bbc.com)
  • The purpose of this study was to determine the acute and long-term effects of mitomycin C (MMC) on quiescent rabbit corneal keratocytes regarding cell proliferation, myofibroblast differentiation and DNA repair. (molvis.org)
  • MMC also induced phosphorylation of the nuclear histone marker of DNA damage, γH2AX (a member of the H2A histone family), without induction of cell cycle entry or immediate DNA repair measured by Comet assay. (molvis.org)
  • These data indicate that the effect of MMC on corneal scarring and haze is related to the generation of DNA ICLs leading to defective cell replication and gene expression. (molvis.org)
  • Defects in the control of cell proliferation are a hallmark of cancer, and DNA replication is a key process for cell proliferation. (aacrjournals.org)
  • DNA adducts are subject to DNA repair and necrosis of the cell, which will alter the cumulative dose estimate depending if the exposure is intermittent (allowing for DNA repair time) or constant (no DNA repair time). (who.int)
  • Since it is well recognized that errors in the centrosome duplication contribute to tumorigenesis we are interested in determining the role of replication factors in preventing aneuploidy. (nii.res.in)
  • This suggests that genetic code could be transferred from DNA and RNA onto L-aTNA and vice versa. (astrobiology.com)
  • A p53 dependent checkpoint pathway prevents re-replication. (nii.res.in)
  • Previous research has shown that in space, DNA suffers a higher rate of mutation - for example, substitutions of single nucleotides, crosslinks, inversions, or deletions - due to damage from cosmic rays and solar particles. (nanowerk.com)
  • The combined effect of greater damage and decreased replication accuracy could lead to premature aging in astronauts. (nanowerk.com)
  • Contains polyphenol antioxidants to protect against oxidative damage to DNA and support healthy cellular replication throughout the body. (pennherb.com)
  • The same virus that causes cold sores appears to create lasting damage in the brain - a discovery that could suggest exciting new treatments for dementia. (bbc.com)
  • We suggest that repeated activation causes cumulative damage, leading eventually to Alzheimer's disease in people with the APOE4 gene. (bbc.com)
  • DNA damage was evaluated in both cultured keratocytes and live rabbit eyes following treatment with MMC. (molvis.org)
  • The short pieces of lagging-strand DNA are named Okazaki fragments in honor of their discoverer, Reiji Okazaki. (blogspot.com)
  • Okazaki fragments are eventually joined to produce a continuous strand of DNA. (blogspot.com)
  • The team also demonstrated that L-aTNA fragments could interlink on DNA and RNA templates. (astrobiology.com)
  • It reviewed procedures for responding to requests for the distribution of short DNA fragments of the 1 Russian State Research Centre of Virology and Biotechnology, Koltsovo, Novosibirsk Region, Russian Federation, and the Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America. (who.int)
  • I have found the strongest evidence yet that the herpes virus is a cause of Alzheimer's, suggesting that effective and safe antiviral drugs might be able to treat the disease. (bbc.com)
  • Conclusions The small amount of psilocin renally excreted suggests that no dose reduction is needed for subjects with mild-moderate renal impairment. (researchgate.net)
  • Despite the large evolutionary gap between humans and cyanobacteria, these tiny organisms can provide insights into critical cellular functions such as DNA replication . (phys.org)
  • Exogenous RRM2 expression rescued hallmarks of replication stress induced by co-inhibiting IGF with CHK1 or WEE1, identifying RRM2 as a critical target of the functional IGF:CHK1 and IGF:WEE1 interactions. (nature.com)
  • This indicates that wild-type S. enterica uses base excision repair to remove DNA damages caused by the bile salts. (wikipedia.org)
  • DNA replication typically begins when the clock state corresponds to the morning, and is suppressed when the clock predicts the arrival of night. (phys.org)