RT Journal Article
T1 Regulation of human polλ by ATM-mediated phosphorylation during non-homologous end joining.
A1 Sastre-Moreno, Guillermo
A1 Pryor, John M
A1 Moreno-Oñate, Marta
A1 Herrero-Ruiz, Andrés M
A1 Cortés-Ledesma, Felipe
A1 Blanco, Luis
A1 Ramsden, Dale A
A1 Ruiz, Jose F
AB DNA double strand breaks (DSBs) trigger a variety of cellular signaling processes, collectively termed the DNA-damage response (DDR), that are primarily regulated by protein kinase ataxia-telangiectasia mutated (ATM). Among DDR activated processes, the repair of DSBs by non-homologous end joining (NHEJ) is essential. The proper coordination of NHEJ factors is mainly achieved through phosphorylation by an ATM-related kinase, the DNA-dependent protein kinase catalytic subunit (DNA-PKcs), although the molecular basis for this regulation has yet to be fully elucidated. In this study we identify the major NHEJ DNA polymerase, DNA polymerase lambda (Polλ), as a target for both ATM and DNA-PKcs in human cells. We show that Polλ is efficiently phosphorylated by DNA-PKcs in vitro and predominantly by ATM after DSB induction with ionizing radiation (IR) in vivo. We identify threonine 204 (T204) as a main target for ATM/DNA-PKcs phosphorylation on human Polλ, and establish that its phosphorylation may facilitate the repair of a subset of IR-induced DSBs and the efficient Polλ-mediated gap-filling during NHEJ. Molecular evidence suggests that Polλ phosphorylation might favor Polλ interaction with the DNA-PK complex at DSBs. Altogether, our work provides the first demonstration of how Polλ is regulated by phosphorylation to connect with the NHEJ core machinery during DSB repair in human cells.
YR 2017
FD 2017-01-17
LK http://hdl.handle.net/10668/10796
UL http://hdl.handle.net/10668/10796
LA en
DS RISalud
RD Apr 17, 2025