What does DNA damage response do?
The DNA damage response is a network of cellular pathways that sense, signal and repair DNA lesions. Surveillance proteins that monitor DNA integrity can activate cell cycle checkpoints and DNA repair pathways in response to DNA damage, to prevent the generation of potentially deleterious mutations.
How does DNA affect gene expression?
Gene expression is the process the cell uses to produce the molecule it needs by reading the genetic code written in the DNA. To do this, the cell interprets the genetic code, and for each group of three letters it adds one of the 20 different amino acids that are the basic units needed to build proteins.
What are the mechanism supporting the DNA damage response?
Fortunately, cells contain multiple DNA repair mechanisms including: base excision repair (BER) that removes damaged bases, mismatch repair (MMR) that recognizes base incorporation errors and base damage, nucleotide excision repair (NER) that removes bulky DNA adducts, and cross-link repair (ICL) that removes …
Why are genes involved in DNA damage response so often mutated in cancer?
Dysregulation of DNA repair genes affects the response of cells to DNA damaging anti-cancer treatment. Upregulation of DNA repair pathways can cause resistance to chemotherapy and radiotherapy, so inhibitors of these pathways have the potential to sensitize cancer cells to these agents (7, 8).
What happens if DNA repair genes are mutated?
DNA repair genes When these genes are mutated, mismatches (mistakes) in the DNA remain. If these mistakes happen in tumor suppressor genes or proto-oncogenes, this will lead to uncontrolled cell growth and tumor formation.
Where is DNA damage checkpoint?
A DNA damage checkpoint is a pause in the cell cycle that is induced in response to DNA damage to ensure that the damage is repaired before cell division resumes. Proteins that accumulate at the damage site typically activate the checkpoint and halt cell growth at the G1/S or G2/M boundaries.
How can damage DNA lead to mutation?
DNA can be damaged by radiation and reactive molecules, such as free radicals. As discussed in the animation, this damage may create mutations by chemically changing the DNA. Most mutations are corrected by DNA repair processes in the cell. In rare cases, however, mutations can accumulate and cause genetic diseases such as cancer.
How do enzymes repair DNA?
Some enzymes work to repair DNA strands. These types of proteins actively travel along a strand to check for any errors or injuries. They repair the strands that are damaged by creating new cells with the correct DNA inscriptions. There are DNA enzymes that attach to certain portions of the strand.
How can DNA be damaged?
DNA can be damaged via environmental factors as well. Environmental agents such as UV light, ionizing radiation, and genotoxic chemicals. Replication forks can be stalled due to damaged DNA and double strand breaks are also a form of DNA damage.
How can mutations in DNA be possibly repaired?
Repair of mutations. Permanent changes in the DNA sequence, called mutations, can have serious consequences for cells and are repaired through mismatch repair, chemical reversal, excision repair, and double-stranded break repair . Some errors are not corrected during replication, but are instead corrected immediately after replication is completed; this type of repair is known as mismatch repair.