Tamar Kleinberger Lab
Department of Microbiology
Rappaport Faculty of Medicine
Technion - Israel Institute of Technology
RESEARCH PROJECTS
1. The association of E4orf4 with the ACF chromatin remodeling factor
A. E4orf4 recruits the phosphatase PP2A to chromatin: What does it do there?
B. E4orf4 inhibits the ACF chromatin remodeling factor: what are the mechanisms responsible for this inhibition?
C. The association of E4orf4 with ACF contributes to E4orf4 functions: How?
E4orf4 recruits the phosphatase PP2A to ACF:
PP2A co-immunoprecipitates with Acf1 in the presence of E4orf4 but not in its absence.
ACF inhibition contributes to E4orf4-induced cell death.
Expression of an shRNA specific for the Acf1 subunit of ACF was induced by doxycycline (Dox). This shRNA was not expressed when only the solvent control (EtOH) was added. After 3 days the cells were transfected with plasmids expressing E4orf4 or an empty vector together with a plasmid expressing GFP-tagged Acf1 which was rendered resistant to the shRNA by the introduction of silent mutations, or its corresponding empty vector. Twenty four hrs after transfection the cells were assayed for cell death (A) or for protein levels (B).
The figure shows that reduced Acf1 expression resulted in increased E4orf4-induced cell death. When Acf1 was re-expressed in the cells, cell death was reduced back to normal levels.
2. Study of E4orf4-induced cell death in a multicellular organism: Drosophila melanogaster
A. E4orf4-induced cell death in normal Drosophila tissues.
B. E4orf4-induced cell death in Drosophila cancer models.
E4orf4 induces dose-dependent phenotypes in the Drosophila eye and wing
A. E4orf4 expression levels rise with increasing temperatures when using the UAS-GAL4 expression system.
C-P. Increasing E4orf4 levels induce increasing damage to the Drosophila eye (GMR>E4orf4, small eye phenotype) and wing (en>E4orf4, damage to wing substructures). No damage is seen with GFP control.
E4orf4 expression prevents cancer formation in the Drosophila eye​
