What are the mechanisms 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 …

Which DNA repair mechanism uses DNA glycosylases?

DNA glycosylases are a family of enzymes involved in base excision repair, classified under EC number EC 3.2. 2. Base excision repair is the mechanism by which damaged bases in DNA are removed and replaced. DNA glycosylases catalyze the first step of this process.

What are the different mechanisms by which DNA can be damaged?

DNA bases can be damaged by: (1) oxidative processes, (2) alkylation of bases, (3) base loss caused by the hydrolysis of bases, (4) bulky adduct formation, (5) DNA crosslinking, and (6) DNA strand breaks, including single and double stranded breaks.

What does DNA damage response mean?

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 damage impact health and life?

DNA damage contributes to aging via cell autonomous events such as causing apoptosis, which depletes functional cells such as neurons, and via cell non-autonomous mechanisms such as triggering senescence, which can negatively impact the function of neighboring, undamaged cells through their SASP.

Why are DNA repair mechanisms important?

DNA Damage Delays Progression of the Cell Cycle Because of the importance of maintaining intact, undamaged DNA from generation to generation, cells have an additional mechanism that helps them respond to DNA damage: they delay progression of the cell cycle until DNA repair is complete.

What are the two types of DNA repair?

There are two main mechanisms for repairing double strand breaks: homologous recombination and classical nonhomologous end joining. Homologous recombination involves the exchange of nucleotide sequences to repair damaged bases on both strands of DNA through the utilization of a sister chromatid.

What is the function of DNA glycosylases?

DNA glycosylases play a key role in the elimination of such DNA lesions; they recognize and excise damaged bases, thereby initiating a repair process that restores the regular DNA structure with high accuracy.

What is the function of DNA glycosylases enzyme involved in base excision repair?

Enzymes that cleave the bond between deoxyribose and a modified or mismatched DNA base are now called DNA glycosylases. Collectively these enzymes initiate base excision repair of a large number of base lesions, each recognized by one or a few DNA glycosylases with overlapping specificities.

What are the three types of DNA damage?

DNA damage can be subdivided into two types: (1) endogenous damage caused by reactive oxygen species (ROS) that are derived from metabolic byproducts and (2) exogenous damage caused by radiation (UV, X-ray, gamma), hydrolysis, plant toxins, and viruses.

What are the 4 types of DNA mutations?

Summary

  • Germline mutations occur in gametes. Somatic mutations occur in other body cells.
  • Chromosomal alterations are mutations that change chromosome structure.
  • Point mutations change a single nucleotide.
  • Frameshift mutations are additions or deletions of nucleotides that cause a shift in the reading frame.