The AAA ATPase p97: from the use of genetics to the development of new chemical tools to study its functions

p97/CDC-48 is an AAA+ ATPase involved in many functions along the cell cycle. p97 was discovered for its involvement in cell division, but its underlying mechanisms during mitosis are not well understood yet because its depletion cause aberrant phenotypes which complicate the analysis of its functions. To overcome this problem, researchers have been studying its adaptor proteins to uncover new p97 functions and its mechanisms. Another method to study p97 functions consists in using p97 inhibitors to have temporal resolution. The available p97 inhibitors are very efficient and potent in inhibiting p97 and usually cells undergo apoptosis upon treatment with these drugs. To study p97 functions in this thesis, we used in one side genetic tools, to study the role of UBXN-2 , a p97 adaptor, in regulating spindle orientation in the one-cell embryo of C. elegans, and on the other side, we isolated new chemical tools that affect p97 function by performing two screens with different objectives. Our data provide a new regulation mode of UBXN-2 in regulating spindle orientation in mitosis. In addition, we present new chemical tools that will help the p97 field to better understand the mechanisms governing its functions and, maybe, uncover new roles yet unknown

Discovery of a New Binding Site on Human Choline Kinase α1: Design, Synthesis, Crystallographic Studies, and Biological Evaluation of Asymmetrical Bispyridinium Derivatives

Human choline kinase α (CKα) is a validated drug target for the treatment of cancer. In recent years, a large number of CK inhibitors have been synthesized, and one of them is currently being evaluated in Phase I clinical trials as a treatment for solid tumors. Here we have evaluated a new series of asymmetrical biscationic CK inhibitors by means of enzymatic, crystallographic, and antitumor studies. We demonstrate that one of these structures adopts a completely new binding mode not observed before inducing the aperture of an adjacent binding site. This compound shows antiproliferative and apoptotic effects on cancer cells through activation of caspase-3. Therefore, this study not only provides fruitful insights into the design of more efficient compounds that may target different regions in CKα1 but also explains how these compounds induce apoptosis in cancer cells