The heterodimer Ku70/80 (Ku) is a central actor of the c-NHEJ as it rapidly recognizes broken DNA ends in the cell and protects them from nuclease activity. It subsequently recruits many c-NHEJ effectors, including nucleases, polymerases, and the DNA ligase 4 complex.

Ku70 is a heterodimeric protein made up of Ku70 and Ku80, which together form Ku. In humans, is encoded by the XRCC6 gene. [5][6] Ku70 plays a critical role in the DNA repair, maintenance and many other cellular processes. Together, Ku70 and Ku80 make up the Ku heterodimer form a quasi-symmetric structure, which encircles the double-stranded DNA.

Eukaryotic Ku is a heterodimer of two polypeptides, Ku70 (XRCC6) and Ku80 (XRCC5), so named because the molecular weight of the human Ku proteins is around 70 kDa and 80 kDa. The two Ku subunits form a basket-shaped structure that threads onto the DNA end. [1]

Simplified, Ku70/80 complex is a sensor of DSBs that initiates the assembly of C-NHEJ complex to restore the integrity of a DNA molecule. In fact, the role of Ku70/80 proteins is highly complex and integrates different aspects of DNA repair.

Jan 26, 2024 · Mechanistically, Ku70 translocates from the nucleus into the cytoplasm where it binds to cytosolic DNA and interacts with the GTPase Ras and the kinase Raf, forming a tripartite protein complex and docking at Rab5 + Rab7 + early-late endosomes.

In this study, we show that human Ku70/80 interacts with hTR, the RNA template of human telomerase both in vitro and in vivo. Minimally, Ku70/80 can interact with a region of 47 nt in the 3′ end of hTR and the predicted secondary structure of this region appears to be similar to the Ku70/80 binding region of yeast TLC1.

The Ku heterodimer (Ku70/Ku80) is a main component of the nonhomologous end-joining (NHEJ) pathway that repairs DNA double-strand breaks (DSBs). Ku binds the broken DNA end and recruits other proteins to facilitate the processing and ligation of the broken end.

Jan 1, 2015 · In eukaryotes, Ku is a heterodimer comprised of two subunits, Ku70 and Ku80, that is best characterized for its central role as the initial DNA end binding factor in the “classical” non-homologous end joining (C-NHEJ) pathway, the main DNA double-strand break (DSB) repair pathway in mammals.

May 1, 2004 · Ku is a heterodimer composed of two subunits — Ku70 and Ku80 — that binds to DNA ends in a sequence-independent manner. From crystallographic studies, we know that it is shaped like an asymmetric...

Jul 27, 2023 · The Ku70/80 heterodimer is a key player in non-homologous end-joining DNA repair but is involved in other cellular functions like telomere regulation and maintenance, in which Ku’s role is...