Details

Autor(en) / Beteiligte

• Pannunzio, Nicholas R.
• Watanabe, Go
• Lieber, Michael R.

Titel

Nonhomologous DNA end-joining for repair of DNA double-strand breaks

Ist Teil von

• The Journal of biological chemistry, 2018-07, Vol.293 (27), p.10512-10523

Ort / Verlag

United States: Elsevier Inc

Erscheinungsjahr

2018

Quelle

MEDLINE

Beschreibungen/Notizen

• Nonhomologous DNA end-joining (NHEJ) is the predominant double-strand break (DSB) repair pathway throughout the cell cycle and accounts for nearly all DSB repair outside of the S and G2 phases. NHEJ relies on Ku to thread onto DNA termini and thereby improve the affinity of the NHEJ enzymatic components consisting of polymerases (Pol μ and Pol λ), a nuclease (the Artemis·DNA-PKcs complex), and a ligase (XLF·XRCC4·Lig4 complex). Each of the enzymatic components is distinctive for its versatility in acting on diverse incompatible DNA end configurations coupled with a flexibility in loading order, resulting in many possible junctional outcomes from one DSB. DNA ends can either be directly ligated or, if the ends are incompatible, processed until a ligatable configuration is achieved that is often stabilized by up to 4 bp of terminal microhomology. Processing of DNA ends results in nucleotide loss or addition, explaining why DSBs repaired by NHEJ are rarely restored to their original DNA sequence. Thus, NHEJ is a single pathway with multiple enzymes at its disposal to repair DSBs, resulting in a diversity of repair outcomes.