DNA repair

DNA repair is a collection of processes by which a <a href="/facts/Cell_(biology)/bLM9UQvy">cell</a> identifies and corrects damage to the <a href="/facts/DNA/nB89Iauz">DNA</a> molecules that encode its <a href="/facts/Genome/31Sm08JT">genome</a>. A weakened capacity for DNA repair is a risk factor for the development of <a href="/facts/Cancer/PVW6n1D0">cancer</a>.
DNA is constantly modified in <a href="/facts/Cell_(biology)/bLM9UQvy">cells</a>, by internal <a href="/facts/Metabolism/WxDrm8k5">metabolic by-products</a>, and by external <a href="/facts/Ionizing_radiation/vw0d9GaT">ionizing radiation</a>, <a href="/facts/Ultraviolet_light/kncBUqn5">ultraviolet light</a>, and <a href="/facts/Medicine/2fnp90Je">medicines</a>, resulting in spontaneous DNA damage involving tens of thousands of individual <a href="/facts/Molecular_lesion/WcxnekKf">molecular lesions</a> per cell per day. DNA modifications can also be programmed.
Molecular lesions can cause structural damage to the DNA molecule, and can alter or eliminate the cell's ability for <a href="/facts/Transcription_(biology)/bDgp9HDN">transcription</a> and <a href="/facts/Gene_expression/alCPohLR">gene expression</a>. Other lesions may induce potentially harmful <a href="/facts/Mutation/Ee4NnWbY">mutations</a> in the cell's genome, which affect the survival of its daughter cells after it undergoes <a href="/facts/Mitosis/ExxrSUs8">mitosis</a>. As a consequence, the DNA repair process is constantly active as it responds to damage in the DNA structure. When normal repair processes fail, including <a href="/facts/Apoptosis/8dVzSm4y">apoptosis</a>, irreparable DNA damage may occur, that may be a risk factor for cancer.
The degree of DNA repair change made within a cell depends on various 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 can no longer effectively repair its DNA may enter one of three possible states:

<ol><li>an irreversible state of dormancy, known as <a href="/facts/Cellular_senescence/w6f0gfrB">senescence</a></li>
<li><a href="/facts/Apoptosis/8dVzSm4y">apoptosis</a> a form of <a href="/facts/Programmed_cell_death/DWWhHTKj">programmed cell death</a></li>
<li>unregulated division, which can lead to the formation of a <a href="/facts/Tumor/K0ytzmPz">tumor</a> that is <a href="/facts/Cancer/PVW6n1D0">cancerous</a></li></ol>
The DNA repair ability of a cell is vital to the integrity of its genome and thus to the normal functionality of that organism. Many genes that were initially shown to influence <a href="/facts/Life_expectancy/uPc8bWWW">life span</a> have turned out to be involved in DNA damage repair and protection.

The 2015 <a href="/facts/Nobel_Prize_in_Chemistry/8Nb8Ajjy">Nobel Prize in Chemistry</a> was awarded to <a href="/facts/Tomas_Lindahl/NavCKpm7">Tomas Lindahl</a>, <a href="/facts/Paul_Modrich/PD0RauTz">Paul Modrich</a>, and <a href="/facts/Aziz_Sancar/BzurPXBT">Aziz Sancar</a> for their work on the molecular mechanisms of DNA repair processes.

DNA repair open-in-new

DNA repair