Influence of the live cell DNA marker DRAQ5 on chromatin-associated processes.

In the last decade, live cell fluorescence microscopy experiments have revolutionized cellular and molecular biology, enabling the localization of proteins within cellular compartments to be analysed and to determine kinetic parameters of enzymatic reactions in living nuclei to be measured. Recently, in vivo DNA labelling by DNA-stains such as DRAQ5, has provided the opportunity to measure kinetic reactions of GFP-fused proteins in targeted areas of the nucleus with different chromatin compaction levels. To verify the suitability of combining DRAQ5-staining with protein dynamic measurements, we have tested the cellular consequences of DRAQ5 DNA intercalation.

Protein arginine (N)-methyl transferase 7 (PRMT7) as a potential target for the sensitization of tumor cells to camptothecins.

PRMT7 belongs to the protein arginine methyl-transferases family. We show that downregulation of PRMT7alpha and beta isoforms in DC-3F hamster cells was associated with increased sensitivity to the Top1 inhibitor camptothecin (CPT). This effect was not due to a change in Top1 contents or catalytic activity, or to a difference in the reversal of DNA breaks.

Localisation of human DNA polymerase kappa to replication foci.

The replication of the undamaged genomic DNA requires error-free DNA polymerases delta and epsilon as part of a protein complex that acts continuously along the double helix. In contrast, when the genomic structure is perturbed, DNA replication needs to function more flexibly to bypass DNA distortions. It has been proposed that the newly discovered error prone DNA polymerases play a role in the replication of irregular structure.