ABSTRACT
DNA-dependent protein kinase (DNA-PK) is a trimeric complex comprised of the DNA-PK catalytic subunit (DNA-PKcs) and the autoantigens, Ku86 and Ku70. DNA-dependent protein kinase has attracted enormous interest because it is critically important for four distinct, but probably mechanistically overlapping, processes in vertebrate cells: (i) the generation of a functional immune system through lymphoid variable(diversity)joining [V(D)J] recombination, (ii) immunoglobulin isotype switch recombination, (iii) the repair of spontaneous and exogenously generated DNA double-strand breaks (DSBs) via nonhomologous end joining (NHEJ), and (iv) telomere length maintenance and function.
