Recruitment Kinetics of DNA Repair Proteins Mdc1 and Rad52 but Not 53BP1 Depend on Damage Complexity

• DOI: 10.1371/journal.pone.0041943
• Publication Date: 2012-07-30T21:13:44Z
• Authors: Volker Hable; Guido A. Drexler; Tino Brüning; Christian Burgdorf; Christoph Greubel; Anja Derer; Judith Seel; Hilmar Strickfaden; Thomas Cremer; Anna A. Friedl; Günther Dollinger
• Keywords: RAD52; Linear energy transfer

The recruitment kinetics of double-strand break (DSB) signaling and repair proteins Mdc1, 53BP1 Rad52 into radiation-induced foci was studied by live-cell fluorescence microscopy after ion microirradiation. To investigate the influence damage density complexity on kinetics, which cannot be done UV laser irradiation used in former studies, we utilized 43 MeV carbon ions with high linear energy transfer per (LET = 370 keV/µm) to create a large fraction clustered DSBs, thus forming complex DNA damage, 20 protons low LET 2.6 mainly isolated DSBs. Kinetics for all three characterized time lag period T0 irradiation, during no are formed. Subsequently, accumulate characteristic mean times τ1. Mdc1 accumulates faster (T0 17±2 s, τ1 98±11 s) than 77±7 310±60 irradiation. However, slows down 73±16 1050±270 is slower that but exhibits same dependence LET. In contrast, remains almost constant when varying Comparison literature data shows this rather resembles ionizing radiation. So work quality has processes considered comparing different studies.