• polymerase
  • Researchers at NYU School of Medicine have found that an enzyme known as RNA polymerase is responsible for identifying any DNA damage in the genome and also to recruit partners to repair it. (medindia.net)
  • Scientists have long known that RNA polymerase slides along the telltale tracks of double-stranded DNA and uses that template to create a growing chain of RNA molecules. (medindia.net)
  • In the new study, the NYU School of Medicine researchers reveal how another enzyme called UvrD helicase acts like a train engine to pull the RNA polymerase backwards and expose the broken DNA so a repair crew can get to work. (medindia.net)
  • The study by Dr. Nudler's group and colleagues in Russia used a battery of biochemical and genetic experiments to directly link UvrD to RNA polymerase and to demonstrate that UvrD's pulling activity is essential for DNA repair. (medindia.net)
  • Those two partners then recruit a repair crew of other proteins to patch up the exposed DNA tracks before the train-like polymerase continues on its way. (medindia.net)
  • Our results imply that a major role of RNA polymerase is to patrol the genome for DNA damage," he says. (medindia.net)
  • thymine
  • Subtle changes in the pairing of the chemical letters of DNA--adenine, cytosine, guanine and thymine--produce new cells with different traits than their ancestors. (scientificamerican.com)
  • ESR Spectra for Protonated Thymine and Cytidine Radical Anions: Their Relevance to Irradiated DNA. (springer.com)
  • Other names for the "direct DNA damage" are: thymine dimers pyrimidine dimers Cyclobutane Pyrimidine Dimers (CPDs) UV-endonuclease-sensitive-sites (ESS) Due to the excellent photochemical properties of DNA, this nature-made molecule is damaged by only a tiny fraction of the absorbed photons. (wikipedia.org)
  • genes
  • Many genes that were initially shown to influence lifespan have turned out to be involved in DNA damage repair and protection. (medicalxpress.com)
  • Human populations studies show that single-nucleotide polymorphisms in DNA repair genes, causing up-regulation of their expression, correlate with increases in longevity. (wikipedia.org)
  • Cells
  • Nevertheless, there are arguments against this point of view (1) and, even if damage to DNA is the important element in cancer initiation, one should always keep in mind the possibilities that the switch from normal to cancer cells may arise from faulty transcription and hence translation (as seems to be the case in the death of UV-irradiated arrested human fibroblasts). (springer.com)
  • The damage is caused when these particles enter the body and form free radicals in the body's cells. (innovations-report.com)
  • In cells, the damage caused by ionizing radiation is mainly due to free-radical-induced alterations of their DNA. (springer.com)
  • Work on how cells repair damaged DNA landed Swedish, U.S. and Turkish scientists the Nobel Prize for Chemistry last year and AstraZeneca's recently approved Lynparza is an early example of a drug that builds on this new understanding. (foxnews.com)
  • The excited state lifetime of these substances is 1,000 to 1,000,000 times longer than the lifetime of melanin, and therefore they may cause damage to living cells that come in contact with them. (wikipedia.org)
  • Un-repaired DNA damages accumulate in non-replicating cells, such as cells in the brains or muscles of adult mammals and can cause aging. (wikipedia.org)
  • Cells that have a defective G2-M checkpoint enter mitosis before repairing their DNA, leading to death after cell division. (wikipedia.org)
  • The accumulation of unrepaired DNA damage is more prevalent in certain types of cells, particularly in non-replicating or slowly replicating cells, such as cells in the brain, skeletal and cardiac muscle. (wikipedia.org)
  • Cells can also be induced to senesce via DNA damage in response to elevated reactive oxygen species (ROS), activation of oncogenes and cell-cell fusion, independent of telomere length. (wikipedia.org)
  • The nucleus of senescent cells is characterized by senescence-associated heterochromatin foci (SAHF) and DNA segments with chromatin alterations reinforcing senescence (DNA-SCARS). (wikipedia.org)
  • Consistent with this, telomerase-immortalised cells continued to age (according to the epigenetic clock) without having been treated with any senescence inducers or DNA-damaging agents, re-affirming the independence of the process of epigenetic ageing from telomeres, cellular senescence, and the DNA damage response pathway. (wikipedia.org)
  • As this damage accumulates, it can lead to malfunctioning cells or cell death. (wikipedia.org)
  • The gametes contain DNA for fertilization of an ovum Sertoli cells - the true epithelium of the seminiferous epithelium, critical for the support of germ cell development into spermatozoa. (wikipedia.org)
  • reaction
  • H-abstraction from suitable solutes, some experiments are reported which probe this type of reaction with dilute DNA solutions. (springer.com)
  • This reaction allows for hydrogen peroxide created by radiolysis of water to diffuse to the nucleus and react with Iron (II) to produce hydroxyl radicals, which in turn react with DNA. (wikipedia.org)
  • mitosis
  • DNA damage inhibits M-CDKs which are a key component of progression into Mitosis. (wikipedia.org)
  • Overexpression of chk1 also rescues the radiation sensitivity of rad mutants, presumably by allowing DNA repair to take place before entry into mitosis. (wikipedia.org)
  • In general, cohesion is established during S phase as DNA is replicated, and is lost when chromosomes segregate during mitosis and meiosis. (wikipedia.org)
  • genome
  • The question, he says, boils down to this: Why do RNA polymerases transcribe most of the genome within humans and other organisms, converting vast stretches of DNA to RNA, when only a tiny fraction of those resulting RNA transcripts will ever prove useful? (medindia.net)
  • The DNA repair ability of a cell is vital to the integrity of its genome and thus to its normal functioning and that of the organism. (medicalxpress.com)
  • nucleotide
  • The fundamental basis of such change is called a single nucleotide polymorphism, or a copying error in the long, chemical book of DNA. (scientificamerican.com)
  • A. Adhikary, E. Bothe, C. von Sonntag, and V. Jain (1997) DNA protection by bisbenzimadozol derivative Hoechst 33258: model studies on the nucleotide level. (springer.com)
  • Some forms of damage repair included, but are not limited to base excision repair, nucleotide excision repair, and non-homologous end joining. (wikipedia.org)
  • This deficiency reflects the loss of ability to perform the DNA repair process known as transcription coupled nucleotide excision repair (TC-NER). (wikipedia.org)
  • pyrimidine
  • R. W. Hart, R. B. Setlow, and A. D. Woodhead, Evidence that pyrimidine dmers in DNA can give rise to tumors, Proc. (springer.com)
  • transcription
  • This is the only molecular machine that is capable of continuously scanning the chromosomes for virtually any deviation from the canonical four bases in the template strand: A, T, G and C." The polymerase's extensive transcription activity, then, might be well worth the effort if its continuous vigilance also ensures that any DNA damage gets fixed through the assistance of the pulling factors and other collaborators. (medindia.net)
  • cause
  • Consequently, any exposure to sunlight can cause serious skin and eye damage and greatly elevate the risk of skin cancer Similarly, children born with Cockayne syndrome age prematurely and are often short in stature due to inadequate DNA repair. (medindia.net)
  • While stress can cause damage, it can also provide the stimulus for undoing the damage. (medicalxpress.com)
  • Since the action spectrum of sunburn is indistinguishable from the absorption spectrum of DNA, it is generally accepted that the direct DNA damages are the cause of sunburn. (wikipedia.org)
  • Overall, they concluded that while the complexity of responses to DNA damage remains only partly understood, the idea that DNA damage accumulation with age is the primary cause of aging remains an intuitive and powerful one. (wikipedia.org)
  • Both cause DNA damage. (wikipedia.org)
  • ROS cause more than 20 types of DNA damage. (wikipedia.org)
  • potentially
  • Some aspects of the effect of O 2 in potentially enhancing the damage and the protective effects of thiols and bisbenzimidazole derivatives are reported. (springer.com)
  • radical
  • E. Bothe, G.A. Qureshi and D. Schulte-Frohlinde (1983) Rate of OH radical induced strand break formation in single stranded DNA under anoxic conditions. (springer.com)
  • Radical-Induced DNA Damage and Specific Implications in Evaluating Genetic Changes. (springer.com)
  • DNA is vulnerable to radical attack because of the very labile hydrogens that can be abstracted and the prevalence of double bonds in the DNA bases that radicals can easily add to. (wikipedia.org)
  • The location and binding of Iron (II) to DNA may play an important role in determining the substrate and nature of the radical attack on the DNA. (wikipedia.org)
  • humans
  • He said that the publication had two main findings: humans evolved an inflammatory response when subjected to DNA damage, and the variation in TLR activity among humans suggests that some people are more prone to inflammation following DNA damage, for example, after receiving cancer therapy. (redorbit.com)
  • Naturally occurring oxidative DNA damages arise at least 10,000 times per cell per day in humans and 50,000 times or more per cell per day in rats, as documented below. (wikipedia.org)