1:00 PM Keynote Address III Bettina Kempkes
Bettina Kempkes studied biology and graduated from the Albert-Ludwig
University Freiburg in 1986. She received her PhD at the Max-Planck
Institute of Immunobiology in Freiburg for her work on the T cell receptor
repertoire of hapten-specific T cells in 1989. Between 1989 and 1994 she
worked as a postdoctoral research fellow at the Helmholtz Center Munich.
From 1994 to 1996 she was a grantee of a fellowship for Research on
Infectious Diseases at the Cancer Center MGH Boston of Harvard Medical School. In 1996 she returned to the Helmholtz Center Munich and became a principal investigator and group leader of the team “Viral Latency”. 2002 she became an associate professor and 2006 an extra-ordinary professor for Molecular Tumor Biology at the Faculty of Biology at the Ludwigs-Maximilian University in Munich.
EBNA2 C-terminus new project
Harter …Song 2016 (PLoS Pathogens) C-TAD EBNA2 in..
- EBNA2 binds to the PLK1 serine/threonine kinase
- PLK1: controls multiple processes in mitosis, also involved in check-point G2/S
- PLK1 interacts with important regulator regions of EBNA2 (poster 174)
- EBNA2 S460 and T468 are phosphorylation by PLK1 in Vito
- S460A and T468V EBNA2 mutants show increased biological activity
- Summary 2: PLK1is a target for cancer therapy thus could be a target for EBNA2 inactivation
Conclusion EBF1 anchors EBNA2 to chromatin…
- The N-terminal dimerization domain of EBNA2 (END)
- Hydrophobic interface of the dimer
- Structural guided mutagenesis The EBNA2 interlace mutatnts L16D and I50D cannot form dimers
- H15A and deflate alpha1 -helix form dimers but can not trans activation LMP1
- Summary 2: The EBNA2 N terminal transactivation domain (END) folds into a dimeric structure required for
- Nucleus (5712) Cytoplasimc(4712?)
- Cellular target genes of EBNA2 and EBNA3A nuclear fraction
- 20% of EBNA2 cellular targets are regulated by EBNA3A
- TOP20 Ensemble gene Co-regulated by EBNA2 and 3A
- The MYC gene is flanked by genes of long non-coding RNAs that are c-regulated by EBNA2
- Normalized ChIP Data
- 82 TFs ENCODE 2012 GM12878, CBF1 Zhao et al 2011 EBNA2 Flag
- Signal intensities of EBNA2 correlate with CBF1 and EBF1 binding intensities
- Early B cell factor
- EBF family: EBF1, EBF2, EBF3, and 4
- Within the hematopoietic system
- EBF1 independent EBNA2 chromatin binding sites: enriched for EBF1 motifs (DG75) and EEBF1 signals (GM12878)
- CBF1 dep EBNA2 binding to chromatin is insensitive to EBF1 knock-down
- EBF1 and EBNA2 physically interact in cellular protein complexes
- (poster 167) the bindings require the protruding alpha-helix
- The EBNA3 gene family members (3A, 3B, 3C) bind to B cell enhances and promoters and regulate transcription
- Use cellular DNA anchors
- Share a homologous domain that binds to CBF1 (RBPJ/CAL/SuH/Lag1)
- Facilitate
- Delta EBNA3A initiate and maintain proliferation of primary human B cells (vs delta EBNA2 —> can’t proliferation)
- EBNA3A positive and negative EBV infected B cells
- CXCL10 is activated in 3A deletion (and 3C deletion, too)
- CXCL10 and CXCL9 are repressed by 3A and 3C (both are located at Chromosome 4
- PcG are located in the CXCL 9 and 10 loci (cool! 值得查一查)
Conditional EBNA-3A systems
- PRTS1 -> Dox inducible 3A
- Loss of Pol II/H3ac precedes the gain of repressive H3K27me3 marks and loss of activation marks H3K4me3 at the CXCL10 gene
- Pol II, H3ac, H3K27me3, H3K4me3
- 3A prevents binding of EBNA2 to enhancer regions
- Repression of interferon induction of CXCL9 and CXCL10 by 3A is CBF1 dependent
- CXCL10 and CXCL9
- Initiation of repression does not require CtBP