Functional redundancy between repair factor XLF and damage response mediator 53BP1 in V(D)J recombination and DNA repair

The classical nonhomologous DNA end-joining (C-NHEJ) double-strand break (DSB) repair pathway in mammalian cells maintains genome stability and is required for V(D)J recombination and lymphocyte development. Mutations in the XLF C-NHEJ factor or ataxia telangiectasia-mutated (ATM) DSB response protein cause radiosensitivity and immunodeficiency in humans. Although potential roles for XLF in C-NHEJ are unknown, ATM activates a general DSB...