Non-homologous end joining

Non-homologous end joining (NHEJ) is one pathway that can be used to repair double-stranded [DNA break]]s. It is non-homologous because no homology is required between the joined DNA strands.

NHEJ is the predominant repair pathway in mammals, but in other organisms such as yeast, homologous recombination dominates. NHEJ is error-prone, and incorrect repair can result in connection of the broken chromosome to the end of annother chromosome. This may result in incorrect gene regulation, and (ultimately) cancer.

A number of proteins are involved in NHEJ, notably the Ku proteins , which also bind to the telomeres. In yeast, Sir2 may play a role in the repair of NHEJ.