DNA repair refers to a collection of processes by which a cell identifies and corrects damage to the DNA molecules that encode its genome. In human cells, both normal metabolic activities and environmental factors such as UV light and radiation can cause DNA damage, resulting in as many as 1 million individual molecular lesions per cell per day. Many of these lesions cause structural damage to the DNA molecule and can alter or eliminate the cell's ability to transcribe the gene that the affected DNA encodes. Other lesions induce potentially harmful mutations in the cell's genome, which affect the survival of its daughter cells after it undergoes mitosis. As a consequence, the DNA repair process is constantly active as it responds to damage in the DNA structure. When normal repair processes fail, and when cellular apoptosis does not occur, irreparable DNA damage may occur, including double-strand breaks and DNA crosslinkages (interstrand crosslinks or ICLs).
The rate of DNA repair is dependent on many factors, including the cell type, the age of the cell, and the extracellular environment. A cell that has accumulated a large amount of DNA damage, or one that no longer effectively repairs damage incurred to its DNA, can enter one of three possible states:
- an irreversible state of dormancy, known as senescence
- cell suicide, also known as apoptosis or programmed cell death
- unregulated cell division, which can lead to the formation of a tumor that is cancerous
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. Many genes that were initially shown to influence life span have turned out to be involved in DNA damage repair and protection. Failure to correct molecular lesions in cells that form gametes can introduce mutations into the genomes of the offspring and thus influence the rate of evolution.
Other articles related to "dna repair, dna, repair":
... He finished his habilitation on DNA repair proteins at the Eidgenössischen Technischen Hochschule Zürich in 1998 ... His main interest is still the DNA repair system ... In 2008, he was awarded the Otto-Bayer-Prize for his work on the DNA repair systems ...
... On some occasions, DNA damage is not repaired, or is repaired by an error-prone mechanism that results in a change from the original sequence ... As a consequence, the rate and accuracy of DNA repair mechanisms have an influence over the process of evolutionary change ...
... Most of the DNA repair deficiency diseases show varying degrees of "accelerated aging" or cancer (often some of both) ... But elimination of any gene essential for base excision repair kills the embryo—it is too lethal to display symptoms (much less symptoms of cancer or "accelerated aging") ... is very often caused by a defective MSH2 gene leading to defective mismatch repair, but displays no symptoms of "accelerated aging" ...
... the connection between mutations in the BRCA2 gene and the operation of DNA repair pathways in cancer cells ... This later led to the development of a PARP inhibitor drug, olaparib, which targets the DNA repair pathways of cancer cells ... drug may also be useful in other patients whose cancer it is linked to an error in their DNA repair pathway ...
... It is still a matter of debate whether DNA repair inhibition or alterations in the status of DNA methylation are responsible for the carcinogenic potential ... As vicinal sulfhydryl groups are frequently found in DNA-binding proteins, transcription factors and DNA-repair proteins, interaction of arsenic with these molecules appears ... However, in vitro, most purified DNA repair enzymes are rather insensitive to arsenic, but in cell culture, As produces a dose-dependent decrease of DNA ligase activity ...
Famous quotes containing the words repair and/or dna:
“The land is the appointed remedy for whatever is false and fantastic in our culture. The continent we inhabit is to be physic and food for our mind, as well as our body. The land, with its tranquilizing, sanative influences, is to repair the errors of a scholastic and traditional education, and bring us to just relations with men and things.”
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“Here [in London, history] ... seemed the very fabric of things, as if the city were a single growth of stone and brick, uncounted strata of message and meaning, age upon age, generated over the centuries to the dictates of some now all-but-unreadable DNA of commerce and empire.”
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