genomemaintenance

Genomemaintenance, sometimes written genome maintenance, refers to the collection of cellular processes that preserve genome integrity by preventing, detecting, and repairing DNA damage and replication errors. It encompasses DNA repair pathways, damage signaling networks, and mechanisms that protect chromosome ends and regulate chromatin structure to ensure faithful DNA replication and genome stability across cell divisions.

Key components include replication fidelity and proofreading by DNA polymerases, mismatch repair, base excision repair for small lesions, and nucleotide excision repair for bulky damage. Double-strand breaks are repaired by homologous recombination or non-homologous end joining, depending on the cell-cycle context and available templates. The choice of pathway is coordinated by damage sensors and signaling proteins.

DNA damage response pathways detect lesions, activate signaling kinases (such as ATM and ATR), enforce cell-cycle checkpoints, and coordinate transcriptional responses. p53 and other effectors decide between repair, senescence, or apoptosis to prevent propagation of damaged genomes.

Telomere maintenance protects chromosome ends through telomerase activity or recombination-based lengthening in certain cells, in concert with the shelterin complex and other protective factors. Chromatin structure and histone modifications regulate access to damaged sites, influencing repair efficiency and preserving epigenetic information.

Defects in genomemaintenance lead to genomic instability and are associated with cancer predisposition, aging-related disorders, and developmental abnormalities. Research uses diverse model organisms to dissect conserved pathways and to inform cancer therapies that exploit repair defects.