Modulation intrinsischer Immunität durch adenovirale Onkoproteine

• Antragsteller: Professor Dr. Thomas Dobner
• Fachliche Zuordnung: Virologie ; Zellbiologie
• Förderung: Förderung von 2013 bis 2017
• Projektkennung: Deutsche Forschungsgemeinschaft (DFG) - Projektnummer 234760463

• Erstellungsjahr: 2018

Zusammenfassung der Projektergebnisse

The human adenovirus type 5 (HAdV5) early regulatory proteins E1B-55K and E4orf6 are multifunctional regulators of HAdV replication and cell transformation that control several processes, including modulation of p53-induced apoptosis and growth arrest, selective late viral mRNA transport and shut-off of host cell protein synthesis. Their lytic and oncogenic properties largely correlate with their ability to interact with and to manipulate a number of cellular key regulators controlling transcription, apoptosis and DNA repair (e.g. p53, Mre11, DNA ligase IV and BLM). In addition, data from our group indicated that the multifunctional properties of the viral proteins are regulated interactions with components of the phosphorylation, ubiquitin- and SUMO-conjugation machineries in the context of PML Nuclear Bodies (PML-NBs). On the basis of these findings it was the aim of this study to analyze the interactions of E1B-55K and E4orf6 with PML isoforms and other PML-NB components and to investigate the functional consequences of these interactions on viral protein functions, cell transformation and HAdV replication. Our data show that E1B-55K and E4orf6 promote viral and cell growth through interactions with (i) cellular factors involved in reprogramming/remodeling of the host chromatin (HOXB7, SPOC1, ATRX, KAP1/TRIM28/TIF-1G), (ii) components of the ubiquitin- and SUMO-conjugation machineries (USP7, UBC9), and (iii) the PML-NB components PML, Sp100 and Daxx. These multiprotein complexes have been implicated in diverse cellular processes such as transcriptional regulation, DNA repair, tumor suppression, and ultimately, they have been defined as important host restriction factors involved in antiviral defense. In parallel, we discovered unique enzymatic-like functions of E1B-55K, which correlate with its growth-promoting and oncogenic activities. We show that E1B-55K can stimulate, in addition to p53, the SUMOylation of Sp100 and, likely, other still unknown target proteins. Besides, our studies indicate a STUbL-like activity for E1B-55K as the viral protein can interact with the SUMO-targeted Ubiquitin-ligase (STUbL) RNF4, promoting Daxx degradation. These results introduce completely new functions for a viral oncoprotein and suggest that this posttranslational activity is an important key to how the HAdV protein promotes viral and cell growth. Altogether these data clearly illustrate the importance of PML-NBs and associated factors in virus growth restriction and suggest that HAdV oncoproteins antagonize the intrinsic antiviral activities of PML-NBs and other tumor suppressors to enable efficient viral replication in a temporally coordinated manner. In addition, these observations establish an exciting link between Ubiquitin, SUMOylation, PML-NBs and viral oncogenesis.

Projektbezogene Publikationen (Auswahl)

• (2013). A ubiquitin-specific protease possesses a decisive role for adenovirus replication and oncogene-mediated transformation. PLoS Pathog 9, e1003273
  Ching, W., Koyuncu, E., Singh, S., Arbelo-Roman, C., Härtl, B., Kremmer, E., Speiseder, T., Meier, C., and Dobner, T.
  
• (2013). Control of human adenovirus type 5 gene expression by cellular Daxx/ATRX chromatin-associated complexes. Nucleic Acids Res 41, 3532-3550
  Schreiner, S., Bürck, C., Glass, M., Groitl, P., Wimmer, P., Kinkley, S., Mund, A., Everett, R.D., and Dobner, T.
  
• (2013). Cross-talk between phosphorylation and SUMOylation regulates transforming activities of an adenoviral oncoprotein. Oncogene 32, 1626-1637
  Wimmer, P., Blanchette, P., Schreiner, S., Ching, W., Groitl, P., Berscheminski, J., Branton, P.E., Will, H., and Dobner, T.
  
• (2013). SPOC1-mediated antiviral host cell response is antagonized early in human adenovirus type 5 infection. PLoS Pathog 9, e1003775-e1003775
  Schreiner, S., Kinkley, S., Bürck, C., Mund, A., Wimmer, P., Schubert, T., Groitl, P., Will, H., and Dobner, T.
  
• (2013). The adenoviral oncogene E1A-13S interacts with a specific isoform of the tumor suppressor PML to enhance viral transcription. J Virol 87, 965-977
  Berscheminski, J., Groitl, P., Dobner, T., Wimmer, P., and Schreiner, S.
  
• (2014). Influence of ND10 components on epigenetic determinants of early KSHV latency establishment. PLoS Pathog 10, e1004274
  Günther, T., Schreiner, S., Dobner, T., Tessmer, U., and Grundhoff, A.
  
• (2014). Sp100 isoform-specific regulation of human adenovirus 5 gene expression. J Virol 88, 6076-6092
  Berscheminski, J., Wimmer, P., Brun, J., Ip, W.H., Groitl, P., Horlacher, T., Jaffray, E., Hay, R.T., Dobner, T., and Schreiner, S.
  
• (2015). KAP1 Is a host restriction factor that promotes human adenovirus E1B-55K SUMO modification. J Virol 90, 930-946
  Bürck, C., Mund, A., Berscheminski, J., Kieweg, L., Müncheberg, S., Dobner, T., and Schreiner, S.
  
• (2016). PML isoforms IV and V contribute to adenovirus-mediated oncogenic transformation by functionally inhibiting the tumor-suppressor p53. Oncogene 35, 69-82
  Wimmer, P., Berscheminski, J., Blanchette, P., Groitl, P., Branton, P.E., Hay, R.T., Dobner, T., and Schreiner, S.
  
• (2016). Sp100A is a tumor suppressor that activates p53-dependent transcription and counteracts E1A/E1B-55K-mediated transformation. Oncogene 35, 31783189
  Berscheminski, J., Brun, J., Speiseder, T., Wimmer, P., Ip, W.H., Terzic, M., Dobner, T., and Schreiner, S.
  
• (2017). Efficient Transformation of Primary Human Mesenchymal Stromal Cells by Adenovirus Early Region 1 Oncogenes. J Virol 91, e01782-16
  Speiseder, T., Hofmann-Sieber, H., Rodriguez, E., Schellenberg, A., Akyüz, N., Dierlamm, J., Spruss, T., Lange, C., and Dobner, T.
  
• (2017). Humanized Mice Reproduce Acute and Persistent Human Adenovirus Infection. J. Infect. Dis. 215, 70-79
  Rodriguez, E., Ip, W.H., Kolbe, V., Hartmann, K., Pilnitz-Stolze, G., Tekin, N., Gomez-Medina, S., Munoz-Fontela, C., Krasemann, S., and Dobner, T.
  
• (2018). Human Adenovirus Core Protein V Is Targeted by the Host SUMOylation Machinery To Limit Essential Viral Functions. J Virol 92, e01451-17
  Freudenberger, N., Meyer, T., Groitl, P., Dobner, T., and Schreiner, S.