Nukleinsyreparation

Nukleinsyreparation, also known as DNA repair, is a collection of cellular processes that identify and correct damage to DNA molecules. DNA is constantly subjected to various insults from both internal sources like metabolic byproducts and external sources such as radiation and chemicals. If left unrepaired, this damage can lead to mutations, genomic instability, and ultimately, cell death or disease, including cancer.

Several major pathways are involved in nucleic acid repair. Base excision repair (BER) corrects small DNA base lesions, such as oxidized or alkylated bases, and also repairs abasic sites. Nucleotide excision repair (NER) removes larger, bulky DNA adducts, like those caused by UV radiation or chemical carcinogens, which distort the DNA helix. Mismatch repair (MMR) corrects errors that escape during DNA replication, such as mismatched bases or small insertions/deletions. Double-strand break repair (DSBR) handles the most severe type of DNA damage, where both strands of the DNA helix are broken. This pathway includes non-homologous end joining (NHEJ), which directly ligates broken ends, and homologous recombination (HR), which uses a homologous template to accurately repair the break.

These repair mechanisms are crucial for maintaining genomic integrity and are essential for the survival and proper functioning of all living organisms. Defects in DNA repair pathways are often associated with increased cancer risk and various genetic disorders.