Overview

Supervisor: Libor Macůrek

Project description

Genome instability is one of the main features of cancer cells. DNA repair and the cell cycle arrest are protective mechanisms that prevent development of the genome instability. The tumor suppressor p53 plays a central role in regulating these events, and its loss leads to tumor development. Function of p53 is controlled by other proteins, including the phosphatase PPM1D. We have recently described oncogenic potential of the C-terminal truncating mutations of PPM1D (1-3). The observed gain-of-function phenotype depends on abnormally increased stability of the truncated PPM1D protein (4). This PhD project aims to identify the molecular mechanism of PPM1D degradation underlying its rapid turnover in normal conditions. We will also address how PPM1D associates with the chromatin which is another crucial determinant of its function (5-7). Besides the classical molecular/cell biology and biochemistry, we will investigate these processes using targeted genome editing by CRISPR/Cas9, analysis of protein complexes by mass spectrometry, evaluation of DNA damage in cell nuclei by high content quantitative microscopy, and identification of the sub-nuclear localization by super-resolution microscopy. Suitable candidates should have an interest in the basic molecular mechanisms occurring in human cells. This project will improve our understanding of the mechanisms leading to cellular transformation by inhibition of p53. In addition, reactivation of p53 function by forced degradation of PPM1D may be a potential strategy for treatment of various cancers.

Suggested reading

Stoyanov M, Martinikova AS, Matejkova K, Horackova K, Zemankova P, Burdova K, Zemanova Z, Kleiblova P, Kleibl Z, Macurek L: PPM1D activity promotes cellular transformation by preventing senescence and cell death. Oncogene 2024.
Martinikova AS, Stoyanov M, Oravetzova A, Kok YP, Yu S, Dobrovolna J, Janscak P, van Vugt M, Macurek L: PPM1D activity promotes the replication stress caused by cyclin E1 overexpression. Mol Oncol 2024 18(1): 6-20.
Burocziova M, Danek P, Oravetzova A, Chalupova Z, Alberich-Jorda M, Macurek L: Ppm1d truncating mutations promote the development of genotoxic stress-induced AML. Leukemia 2023.
Kleiblova P, Shaltiel IA, Benada J, Ševčík J, Pecháčková S, Pohlreich P, Voest EE, Dundr P, Bartek J, Kleibl Z, Medema RH, Macurek L: Gain-of-function mutations of PPM1D/Wip1 impair the p53-dependent G1 checkpoint. J Cell Biol 2013 201(4): 511-21.
Macůrek L, Lindqvist A, Voets O, Kool J, Vos HR, Medema RH: Wip1 phosphatase is associated with chromatin and dephosphorylates gammaH2AX to promote checkpoint inhibition. Oncogene 2010 29(15): 2281-91.
Storchova R, Palek M, Palkova N, Veverka P, Brom T, Hofr C, Macurek L: Phosphorylation of TRF2 promotes its interaction with TIN2 and regulates DNA damage response at telomeres. Nucleic Acids Res 2023.
Jaiswal H, Benada J, Müllers E, Akopyan K, Burdova K, Koolmeister T, Helleday T, Medema RH, Macurek L, Lindqvist A: ATM/Wip1 activities at chromatin control Plk1 re-activation to determine G2 checkpoint duration. EMBO J 2017 36(14): 2161-2176.

APPLY AT: img.cas.cz/phd