Anja Friedrich

Suche


JP01 Studying anti-apoptotic mechanisms of effector proteins from plant and human pathogens in the heterologous system

Principal investigator
Anja Lührmann/Sophia Sonnewald

Mentor
Uwe Sonnewald

 

Functional analysis of cell death suppression of Coxiella burnetii type IV effector CaeB

Many pathogens exert control on processes that regulate cell death, since abrogation of host cell death is often beneficial for the pathogen and facilitates successful invasion. The induction of Programmed Cell Death (PCD) is a genetically controlled and conserved process in eukaryotic cells and results from a complex interaction of microbial proteins with cellular host proteins. Coxiella burnetii is a Gram-negative, obligate intracellular zoonotic pathogen that causes Q-fewer. Inhibition of host cell death is important for the slow growing bacteria C. burnetii to replicate and to establish a successful infection. C. burnetii uses a type IV secretion system to deliver about 130 effector proteins into the host cell. So far, three of them were shown to supress host cell apoptosis, a PCD pathway. Among those is CaeB which was shown to inhibit mitochondrial outer membrane permeabilisation (MOMP) upon staurosporine induced cell death in HEK293 cells, while targeting of Bax to mitochondria was not affected, but direct targets of CaeB could not be uncovered, yet. The aim of our work is to increase the knowledge about how effector proteins mediate cell death suppression and to investigate to which levels the processes are conserved in plants and animals. To this end we analysed the ability of CaeB to suppress PCD in plants and show that CaeB decelerates development of cell death symptoms elicited either by Bax or the interaction between the R-gene Pto and the corresponding avirulence gene AvrPto. Fusion to the green fluorescence protein (GFP) revealed that CaeB localises mainly to the ER in planta. Based on pharmacological studies using tunicamycin to trigger ER stress we propose that CaeB suppresses cell death caused by sever ER stress.

 

 

 

Presentations

October 2016

8th Annual Retreat, Erlangen School of Molecular Communication, Schloss Schney, Lichtenfels, Germany
”Investigating the effect of the Coxiella burnetii type IV effector protein CaeB on ER stress”

Talk
     
October 2015

2nd International SFB 796 Conference: Mechanisms of microbial host cell manipulation: From plants to humans, Erlangen, Germany
The Coxiella burnetii type IV effector protein CaeB is a across kingdoms cell death suppressor

Talk
     
October 2015

2nd International SFB 796 Conference: Mechanisms of microbial host cell manipulation: From plants to humans, Erlangen, Germany
The Coxiella burnetii type IV effector protein CaeB is a across kingdoms cell death suppressor

Poster
     
July 2015

7th Annual Retreat, Erlangen School of Molecular Communication, Schloss Hirschberg, Beilngries, Germany
”The Type IV Effector CaeB from Coxiella burnetii Functions as a Cell Death Suppressor Across Kingdoms”

Poster
   

 

 

 

Awards

Best Talk Award

Second place

8th Annual Retreat, Erlangen School of Molecular Communication, Schloss Schney, Lichtenfels, Germany, October 2016
“Investigating the effect of the Coxiella burnetii type IV effector protein CaeB on ER stress“