DNARepairjärjestelmät

DNARepairjärjestelmät, or DNA repair systems, are a collection of cellular mechanisms that work to correct errors and damage to DNA. DNA is constantly exposed to various sources of damage, both from internal metabolic processes and external environmental factors like radiation and chemicals. If left unrepaired, these lesions can lead to mutations, which can have severe consequences for the cell, including uncontrolled cell division (cancer) or programmed cell death.

These repair systems are vital for maintaining genomic integrity. There are several major pathways involved in DNA repair, each specialized for different types of damage. For instance, base excision repair (BER) corrects small base modifications, while nucleotide excision repair (NER) handles larger, bulky adducts that distort the DNA helix. Mismatch repair (MMR) specifically targets incorrectly paired bases that escape proofreading during DNA replication. Double-strand breaks, a particularly dangerous form of damage, are repaired by homologous recombination (HR) and non-homologous end joining (NHEJ).

The efficiency and accuracy of DNARepairjärjestelmät are crucial for the survival and function of all living organisms. Defects in these repair pathways are linked to a variety of diseases, including cancer predisposition syndromes like xeroderma pigmentosum and Lynch syndrome. Understanding these systems is fundamental to fields such as molecular biology, genetics, and medicine, and it continues to be an active area of research.