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Subdiffusion supports joining of correct ends during repair of DNA double-strand breaks.

ABSTRACT: The mobility of damaged chromatin regions in the nucleus may affect the probability of mis-repair. In this work, live-cell observation and distance tracking of GFP-tagged DNA damage response protein MDC1 was used to study the random-walk behaviour of chromatin domains containing radiation-induced DNA double-strand breaks (DSB). Our measurements indicate a subdiffusion-type random walk process with similar time dependence for isolated and clustered DSBs that were induced by 20 MeV proton or 43 MeV carbon ion micro-irradiation. As compared to normal diffusion, subdiffusion enhances the probability that both ends of a DSB meet, thus promoting high efficiency DNA repair. It also limits their probability of long-range movements and thus lowers the probability of mis-rejoining and chromosome aberrations.

SUBMITTER: Girst S

PROVIDER: S-EPMC3753591 | biostudies-literature | 2013

REPOSITORIES: biostudies-literature

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Subdiffusion supports joining of correct ends during repair of DNA double-strand breaks.

Girst S S Hable V V Drexler G A GA Greubel C C Siebenwirth C C Haum M M Friedl A A AA Dollinger G G

Scientific reports 20130101

The mobility of damaged chromatin regions in the nucleus may affect the probability of mis-repair. In this work, live-cell observation and distance tracking of GFP-tagged DNA damage response protein MDC1 was used to study the random-walk behaviour of chromatin domains containing radiation-induced DNA double-strand breaks (DSB). Our measurements indicate a subdiffusion-type random walk process with similar time dependence for isolated and clustered DSBs that were induced by 20 MeV proton or 43 Me ...[more]

PMID: 23979012

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