Characterization of the ATR kinase of Leishmania major and its role in DNA replication stress signaling.

Abstract

The eukaryotic cell has developed mechanisms to maintain genome integrity, which are constantly challenged by DNA damage and replication impediments. The protein kinase Ataxia-Telangiectasia and Rad3-related (ATR), a member of the phosphatidylinositol 3-kinase-like family, is a master regulator of the eukaryotic response to DNA injuries to ensure genome maintenance and stability. In this PhD thesis, we sought to investigate the conservation and functional relevance of the ATR homolog in the DNA metabolism of Leishmania major, a protozoan parasite with a remarkably plastic genome. We have already used CRIPSR/cas9 genome editing to generate ATR-deficient and ATR-tagged cell lines. ATR-deficient cells are significantly affected by hydroxyurea treatment in their cell cycle progression and growth. We also observed an increased accumulation of single-stranded DNA and aberrant levels of phosphorylated histone H2A, a DNA damage marker, in response to replication stress. The main goals of this BEPE proposal are to expand the characterization of L. major ATR's roles in genome homeostasis in a collaborative interaction with a leading international group in the field. As presented below, the main objectives of the proposal are those we can profit from the in-site training at the Wellcome Centre For Integrative Parasitology. (AU)