Biochemical peculiarities of the different RPA homologues of Arabidopsis thaliana and their influence on enzymes involved in DNA repair and recombination

• Antragstellerin: Dr. Daniela Kobbe
• Fachliche Zuordnung: Genetik und Genomik der Pflanzen
• Förderung: Förderung von 2010 bis 2015
• Projektkennung: Deutsche Forschungsgemeinschaft (DFG) - Projektnummer 169487602

The heterotrimeric DNA single strand binding protein RPA (Replication protein A; canonically composed of RPA1, RPA2 and RPA3) is involved in essential processes like DNA replication, repair and recombination. A differently composed variant (human aRPA) presumably prevents DNA replication in defined tissues - an important issue in the context of cancer. Interestingly, the model plant Arabidopsis thaliana features an even more complex RPA system, as it possesses five different homologs of the largest subunit RPA1, and two homologs of both the RPA2 and the RPA3 subunits. It is assumed that different complexes perform different functions (e.g. in repair, recombination, replication). The theory, that different paralogs perform specialized functions is also exemplified in the RECQ helicase family, with individual homologs being important for repair, recombination and replication. Canonical human RPA was shown to stimulate the unwinding activity of different helicases in vitro, also of the human RECQ helicases. The resulting question of whether and how the different Arabidopsis RPA complexes affect the activities of the different Arabidopsis RECQ helicases should be addressed. This should help to further dissect specialized functions. The analysis should be extended to other DNA processing proteins. For the human Fanconi anemia protein FANCJ interesting functional interactions with RPA were demonstrated. Therefore, the two Arabidopsis homologs of FANCJ, which are also of general interest, should be prepared and analyzed.

• DFG-Verfahren: Sachbeihilfen