DNA damage is the main factor in cancer development. In our collaboration we are studying the main damage repair processes in cell-free conditions (in cellular extracts). Replicating DNA in vitro makes possible to study protein-protein interactions that are involved in DNA repair using various interference agents like mutant proteins, peptides and small molecular weight inhibitors designed to bind to the special interaction interfaces. Adding these agents to extracts of various cells is much easier and could be more quantitative than to try to enter them into living cells.

We are studying three main error bypass/repair pathways: translesion synthesis, template switch and homologous recombination uniting the competencies and expertise of our research groups. The cornerstone of the system is T antigen, a viral protein that can initialise replication of a plasmid DNA in a cellular extract by itself, requiring only the main building blocks (dNTPs) of DNA and some extra ATP.

Various lesions are built into plasmids and we check if a given lesion (for example a UV-induced common pyrimidine dimer photoproduct) is bypassed/repaired by a certain pathway or another during plasmid replication, and how a certain process can be influenced by an interference using a peptide, for example, that was designed to inhibit protein-protein interactions known or suspected to play a role in a that process. Our studies also extend to the examination of helicases known or suspected to be involved in homologous recombination or in resolving the replication-inhibiting G4 DNA superstructures.

The expertise of Dávid Szüts’s group (TTK) in molecular cloning and in detection of DNA damage (for example by next generation sequencing) is efficiently combined with the wide expertise of Mihály Kovács’s group (ELTE TTK) in structure-function studies of recombinant proteins.

Dávid Szüts, Mihály Kovács

Result_May 2020