Mechanistic analysis of DNA damage signaling and bypass upon replication of damaged DNA template in human cells.

Información del proyecto

DNAcheck

Identificador del acuerdo de subvención: 794054

DOI

10.3030/794054

Proyecto cerrado

Fecha de la firma de la CE 15 Marzo 2018

Fecha de inicio 1 Octubre 2018

Fecha de finalización 30 Septiembre 2020

Financiado con arreglo a

• EXCELLENT SCIENCE - Marie Skłodowska-Curie Actions

Coste total

€ 170 121,60

Aportación de la UE

€ 170 121,60

Coordinado por

UNIVERSIDAD DE SEVILLA
Spain

Periodic Reporting for period 1 - DNAcheck (Mechanistic analysis of DNA damage signaling and bypass upon replication of damaged DNA template in human cells.)

Período documentado: 2018-10-01 hasta 2020-09-30

Resumen del contexto y de los objetivos generales del proyecto

The genetic information encoded by DNA is constantly threatened by endogenous or exogenous sources of damage. To safeguard the genome against these insults, cells have evolved DNA damage checkpoints that sense the presence of damaged DNA, block cell cycle progression and ensure that DNA is fully repaired before resuming the cell cycle. However, in many cases, unrepaired lesions remain in the DNA when cells enter S-phase. In this scenario, cells employ DNA damage tolerance mechanisms to complete genome replication and prevent fork breakage. Importantly, these pathways are not restricted to the site of stalling but can also function behind the fork at single-stranded(ss)DNA gaps originated by re-priming of DNA synthesis downstream of lesions.
While it is well known that the accumulation of single-stranded DNA (ssDNA) is the signal that riggers the checkpoint response, it is less clear how and where ssDNA actually arises. Generally, it is assumed to accumulate at stalled replication forks by an uncoupling between replicative helicase and polymerase movement. However, recent evidence found in budding yeast support a model where, in response to polymerase-blocking lesions, replication forks do not stall but recover efficiently by re-priming downstream of the lesions, thus leaving ssDNA gaps behind the fork. It is currently unknown whether this model also applies to vertebrate cells. Hence, this project aimed to address the fundamental question of how DNA damage is sensed during genome replication in human cells.

Trabajo realizado desde el comienzo del proyecto hasta el final del período abarcado por el informe y los principales resultados hasta la fecha

In the course of this project, we have identified a remarkable mechanism that promote the robust activation of the replication checkpoint in human cell lines, which involves the action of different nucleases at ssDNA gaps generated behind replication forks in the presence of lesions on the DNA template. Remarkably, this mechanism did not apply when lesion-less replication stress was induced. Thus, these results have shown further evidence of a dichotomy between the cellular response to damaged DNA template versus replisome problems.
The results of the project have been presented to the scientific community at multiple conferences and workshops and are expected to be published within a year.

Avances que van más allá del estado de la técnica e impacto potencial esperado (incluida la repercusión socioeconómica y las implicaciones sociales más amplias del proyecto hasta la fecha)

The project results have helped to better understand how human cells sense and deal with replicative stress, a process that is highly relevant to human disease such as cancer. Interestingly, deregulation of nuclease levels has been reported in different types of cancer. Hence, these nucleases may offer a target for cancer therapeutic development.

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