The funtion of the protein kinase Nek5 in normal and cancer cells: from the identification of physiological substrates to inhibitor design

Abstract

The genetic material is under constant exogenous and endogenous agressions, which cause DNA lesions. To protect and repair these lesions the cells have different responses that promote DNA repair or tolerance to lesions. The importance of the repair mechanisms is demonstrated by its high evolutionary conservation and by gentic diseases associated to defects in these repair systems and which can lead to carcinogenesis and neurodegeneration. Functional analyses of proteins from the Nek family -of kinases - Nima Related Kinases, specially their protein interaction profiles, pointed to important roles in the cell cycle and in the DNA damage response. Among the members of the family Nek5 family is the least studied. We demonstrated recently its involvement in apoptosis and defective cellular respiration and the formation of reactive oxygen species. Aditionally this protein has a role in DNA repair mechanisms (see manuscript in preparation attached), leading to the activation of important kinases such as ATM and Chk2. Therefore, an important part of this project is the characterization of the mechanisms of action of Nek5 in the repair of DNA. Another focus is the identification of it natural physiological protein substrates through the so called "Shokat" approach, involving the generation of artificial kinases that are sensitive to ATP analogs. Furthermore, the functional alterations of mutations found in the Nek5 gene in cancer will be studied. Finally, we will perform bioassays of inhibitor candidates to discover new inhibitors of Nek5 that may be come to use as anti-cancer reagents. (AU)