mRAD18Sc: a Multifunctional Protein in Replicative Damage Bypass and Gametogenesis

Abstract

Integrity of the genome is of vital importance for life. DNA is constantly under attack from endogenous and exogenous DNA damaging agents. During each round of DNA replication, the replication machinery requires the presence of an intact DNA template. If a DNA lesion is encountered, progression of the replication process is at risk to be blocked. However, replicative damage bypass prevents termination of DNA replication. The proteins that act in replicative damage bypass are capable to operate as a temporary “stand-in” of the replication machinery. This process has been investigated in detail in the yeast S. cerevisiae, and it has become clear that the ubiquitin-conjugating enzyme RAD6 is a key factor in this process. To perform its function, RAD6 interacts with RAD18, an ubiquitin ligase. The aim of the research outlined in this thesis is to provide insight into the role of mammalian homologs of RAD6 and RAD18 in the process of replicative damage bypass (RDB) in somatic cells and during gametogenesis. The mammalian homologs are HR6A and HR6B for RAD6 and mRAD18Sc for RAD18. In this research, live cell imaging and fl uorescence-based technologies are applied to study the subcellular localization and dynamics of fl uorescently tagged HR6B and mRAD18Sc.