Understanding the cellular response to DNA strand breaks is crucial to decipher the mechanisms maintaining the integrity of our genome. In eukaryotic cells, the molecular events triggered by DNA damage are strongly influenced by the local chromatin environment surrounding the lesion. The ensuing DNA repair process, in turn, impacts on chromatin structure.
In order to understand how these two fundamental processes are mutually connected, both chromatin rearrangements induced by DNA damage as well as DNA repair activity have to be visualized in living cells.
Elisa Ferrando-May and a team from University of Konstanz now present a novel method to visualize how the mobility of nuclear proteins changes in response to localized DNA damage. Their new approach enables to inflict DNA damage without interfering with a subsequent mobility measurement by fluorescence photoactivation.
It is based on nonlinear photoperturbation using infrared femtosecond (fs) laser pulses. The assay detects how the dynamics of nuclear proteins is affected by localized DNA strand breaks, irrespective of their recruitment behavior.
The scientists induce DNA strand breaks via nonlinear excitation with fs laser pulses at 1050 nm in a 3D-confined subnuclear volume. After a time delay of choice, they analyze protein mobility within this volume by two-photon photoactivation of PA-GFP fusion proteins at 775 nm. The time delay can be chosen freely permitting to probe protein mobilities at different subsequent stages of the DNA damage response.
By changing the position of the photoactivation spot with respect to the zone of lesion the influence of chromatin structure and of the distance from damage can be investigated. Due to the local confinement of multiphoton absorption it is possible to examine spatially distinct subnuclear areas, such as eu- and heterochromatin.
As first applications, the scientists demonstrated a locally confined, time-dependent mobility increase of histone H1.2, and a progressive retardation of the DNA repair factor XRCC1 at damaged sites. (Text contributed by K. Maedefessel-Herrmann)
M. Tomas, P. Blumhardt, A. Deutzmann, T. Schwarz, D. Kromm, A. Leitenstorfer, E. Ferrando-May, Imaging of the DNA damage-induced dynamics of nuclear proteins via nonlinear photoperturbation, J. Biophotonics 6(8), 645-655 (2013); doi: http://dx.doi.org/10.1002/jbio.201200170Regina Hagen
Scientists unlock ability to generate new sensory hair cells
22.02.2017 | Brigham and Women's Hospital
New insights into the information processing of motor neurons
22.02.2017 | Max Planck Florida Institute for Neuroscience
In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport
Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...
The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.
The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...
Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...
Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".
Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...
13.02.2017 | Event News
10.02.2017 | Event News
09.02.2017 | Event News
22.02.2017 | Power and Electrical Engineering
22.02.2017 | Life Sciences
22.02.2017 | Physics and Astronomy