Different repair mechanisms act on different types of DNA damage; Base Excision Repair removes primarily small chemically altered DNA bases, Nucleotide Excision Repair removes lesions that also give structural changes to the DNA helix, and Mismatch Repair removes normal, but mispaired, bases. Failure to repair can lead a range of complex disorders; cancer, neurodegenerative diseases, accelerated aging, and failure to mount appropriate responses to bacteria and viruses.
Most of our activity is centered around the Base Excision Repair pathway. This pathway is initiated by enzymes that recognize small modifications in DNA and RNA. One example is SMUG1.
One of the most interesting areas of study now is how different DNA repair pathways act together to initiate downstream effects, such as transcription and chromatin remodelling, activation of signaling pathways that induce survival strategies, like autophagy and apoptosis.