What type of DNA damage is repaired using nucleotide excision repair?

What type of DNA damage is repaired using nucleotide excision repair?

Nucleotide excision repair (NER) is a particularly important excision mechanism that removes DNA damage induced by ultraviolet light (UV). UV DNA damage results in bulky DNA adducts – these adducts are mostly thymine dimers and 6,4-photoproducts.

What happens during nucleotide excision repair of damaged DNA?

In nucleotide excision repair, the damaged nucleotide(s) are removed along with a surrounding patch of DNA. In this process, a helicase (DNA-opening enzyme) cranks open the DNA to form a bubble, and DNA-cutting enzymes chop out the damaged part of the bubble.

How is oxidative damage fixed in DNA?

Oxidative DNA damage is repaired via several repair intermediates by base excision repair (BER). Through removal of the oxidized base, a reactive apurinic site (AP site) is formed. Many base modifications are repaired similarly through BER with various glycosylases initially excising the base.

What DNA repair mechanisms can repair DNA damage?

At least five major DNA repair pathways—base excision repair (BER), nucleotide excision repair (NER), mismatch repair (MMR), homologous recombination (HR) and non-homologous end joining (NHEJ)—are active throughout different stages of the cell cycle, allowing the cells to repair the DNA damage.

What triggers nucleotide excision repair?

Nucleotide excision repair (NER) is the main pathway responsible for the removal of bulky DNA lesions induced by UV irradiation, environmental mutagens, and certain chemotherapeutic agents.

What is the result of oxidative DNA damage?

When DNA undergoes oxidative damage, two of the most common damages change guanine to 8-hydroxyguanine or to 2,6-diamino-4-hydroxy-5-formamidopyrimidine.

How do you fix oxidative damage?

Lifestyle and dietary measures that may help reduce oxidative stress in the body include:

1. eating a balanced, healthful diet rich in fruits and vegetables.
2. limiting intake of processed foods, particularly those high in sugars and fats.
3. exercising regularly.
4. quitting smoking.
5. reducing stress.

What happens if base excision repair does not work?

Base Excision Repair Pathway and disease In fact, somatic mutations in Pol β have been found in 30% of human cancers, and some of these mutations lead to transformation when expressed in mouse cells. In many cases, if the damage is not repaired, the cell may resort to induction of apoptosis or necrosis.

How is base excision repaired in oxidative DNA?

Base excision repair (BER) of 8-oxo-7,8-dihydroguanine (8-oxoG). Oxidative DNA damage is repaired via several repair intermediates by base excision repair (BER). Through removal of the oxidized base, a reactive apurinic site (AP site) is formed.

How is oxidative DNA damage related to cancer?

Most cancer treatments cause oxidative DNA damage and DNA strand breaks and thus oxidative DNA damage contributes to long-term side effects in cancer survivors. Therefore unsurprisingly, oxidative DNA damage and its repair have been of high interest for decades, leading to profound knowledge about its biochemistry as a whole [1].

How is DNA damage mediated by the repair process?

Such risks are due to primary oxidative DNA damage and also mediated by the repair process. This leads to a delicate decision process for the cell as to whether to repair a damaged base at a specific genomic location or better leave it unrepaired.

Why is oxidative DNA damage a double edged sword?

This functional role may come as a double-edged sword due to its side effects on mutagenesis and additional genome instability. There are now several datasets published that address oxidative DNA damage and repair genome-wide in human [17], [18], [31], mouse [15], [20], and yeast [16], using various conditions and methodology.