Die Ufmylierung von PARP1 reguliert dessen Reaktion auf replikativen Stress

• Antragsteller: Professor Dr. Zhao-Qi Wang
• Fachliche Zuordnung: Allgemeine Genetik und funktionelle Genomforschung ; Biochemie ; Zellbiologie
• Förderung: Förderung von 2018 bis 2021
• Projektkennung: Deutsche Forschungsgemeinschaft (DFG) - Projektnummer 391593922

• Erstellungsjahr: 2022

Zusammenfassung der Projektergebnisse

DNA replication ensures a faithful replication of genetic information that pass through generations of cells and organisms and therefore is essential for life. Thus, cells evolve a number of cellular mechanisms including the DNA damage response (DDR) to safeguard the fitness and fidelity of DNA replication. PARP1 is a multifaceted protein that conducts PARylation and produces massive PAR in response to various stresses. The homeostasis of the PAR metabolism also plays an important role in the repair of stalled replication forks. PARP inhibitors have been developed as anti-cancer drugs for its synthetic killing in DNA repair-deficient human cancers. However, the biological function of PARP1 and PARylation is poorly understood. The deletion of the entire PARP1 protein cannot simply refer to the functions of PARP1 – the most fascinating of which is that the lack of PARP1 in cells and mouse models leads to both negative (cytotoxic and genotoxic stress) and positive outcomes (protective in inflammatory response). We hypothesize that the PARP1 protein, with its different functional domains and its enzymatic activity that produces PAR, is further complicated by the fact that both PARP1 and PAR have diverse interaction partners, which can influence many pathways within the cell. (1) The biological response of PARP1 UFMylation in various DNA damage. PARylation conducted mainly by PARP1, is perhaps the most rapid response to DNA damage and involved in various DNA repair pathways, such as SSBs and replication stress. Yet modulation of PARP1’s enzymatic activity, for example by posttranslational modification (PTM), has not been well studied. While autoPARylation of PARP1 affects its function in the DNA metabolism such as DNA damage signalling and repair, chromatin remodeling as well as gene transcription, how other PTMs that modify the PARP1 activity to participate in biological and pathological processes have not been investigated. We found that UFMylation is required for full PARP1 activity and a proper replication stress response. The UFMylation mutant PARP1 mice were generated and showed hypersensitivity to replication poison and alkylating agents. Our PARP1 UFMylation mutant mouse model allows to study UFMylation at stalled replication forks or the S-phase checkpoint in vivo, the malfunction of which is often associated with cancer and premature aging. Many functions of PARP1 and PARylation will be tested using these animal models, for example in gene transcription and inflammatory response. It is conceivable that a combination of different inhibitors targeting PARylation and UFMylation, may increase the sensitivity of tumor cells to drug treatment. (2) Separation of function of PARP1 in vivo. PARylation is a dynamic cellular response to stress and its product PAR serves as a scaffold platform to help other partners exert their function, for example in DNA repair and cell cycle checkpoint. To separate the scaffold function of PARP1 from its enzymatic activity, which produces PAR, we generated two enzyme-dead PARP1 mouse models. In a great contrast to PARP1 complete knockout mice, these mutations cause early embryonic lethality in mouse models. However, the biological impact of these two mutations are different: While PARP1E988K mutation blocked embryonic development as early as E2.5 thereby no ES cells can be derived, the PARP1DC truncation mutation apparently is dispensable for the viability of ES cells and their differentiation capacity. However, an extremely low expression of the PARP1DC allele suggests a toxic effect of the C-terminal deletion mutant PARP1, which may beyond its enzymatic activity, but potentially due to the lack of interaction partners of this part of protein. Our current study aims to search for these partners.

Projektbezogene Publikationen (Auswahl)

• Kinetics of poly(ADP-ribosyl)ation, but not PARP1 itself, determines the cell fate in response to DNA damage in vitro and in vivo. Nucleic Acids Res. 45(19):11174-11192 (2017)
  Schuhwerk, H., Bruhn, C., Siniuk, K., Min, W., Erener, S., Grigaravicius, P., Krüger, A., Ferrari, E., Zubel, T., Lazaro, D., Monajembashi, S., Kiesow, K., Kroll, T., Bürkle, A., Mangerich, A., Hottiger, M. & Wang, Z.-Q.
  
• PARPing for Balance in the Homeostasis of Poly(ADP-ribosyl)ation. Seminar Cell Dev Biol 63:81-91 (2017)
  Schuhwerk, H., Atteya, R., Siniuk, K. & Wang, Z.-Q.
  
• XRCC1 Mutation is Associated with PARP1 Hyperactivation and Cerebellar Ataxia. Nature 541(7635):87-91 (2017)
  Hoch, N., Hana, H., Stuart, R., Martine, T., Emilia, K., Ju. L., Zeng, Z., McKinnon, P., Wang, Z.- Q., Wagner, J., Yoon, G., Hornyak, P., Gittens, W., Rey, S., Staras, K., Mancini, G. & Caldecott, K.
  
• The Enigmatic Function of PARP1: From PARylation Activity to PAR Readers. Cells (2019)
  Kamaletdinova, T., Fanaei-Kahrani, Z, & Wang, Z.-Q.
  
• ADP-ribosyltransferases, an update on function and nomenclature. FEBS J. 2021 Jul 29 (2021)
  Lüscher B, Ahel I, Altmeyer M, Ashworth A, Bai P, Chang P, Cohen M, Corda D, Dantzer F, Daugherty MD, Dawson TM, Dawson VL, Deindl S, Fehr AR, Feijs KLH, Filippov DV, Gagné JP, Grimaldi G, Guettler S, Hoch NC, Hottiger MO, Korn P, Kraus WL, Ladurner A, Lehtiö L, Leung AKL, Lord CJ, Mangerich A, Matic I, Matthews J, Moldovan GL, Moss J, Natoli G, Nielsen ML, Niepel M, Nolte F, Pascal J, Paschal BM, Pawłowski K, Poirier GG, Smith S, Timinszky G, Wang Z.-Q., Yélamos J, Yu X, Zaja R, Ziegler M
  
• Biogenesis of Iron–Sulfur Clusters and Their Role in DNA Metabolism. Frontier in Cell and Dev Biol. 9:735678 (2021)
  Shi, R., Hou, W., Wang, Z.-Q. & Xu X.