TY  - JOUR
A1  - Herweg, Jo-Ana
A1  - Hansmeier, Nicole
A1  - Otto, Andreas
A1  - Geffken, Anna C.
A1  - Subbarayal, Prema
A1  - Prusty, Bhupesh K.
A1  - Becher, Dörte
A1  - Hensel, Michael
A1  - Schaible, Ulrich E.
A1  - Rudel, Thomas
A1  - Hilbi, Hubert
T1  - Purification and proteomics of pathogen-modified vacuoles and membranes
JF  - Frontiers in Cellular and Infection Microbiology
N2  - Certain pathogenic bacteria adopt an intracellular lifestyle and proliferate in eukaryotic host cells. The intracellular niche protects the bacteria from cellular and humoral components of the mammalian immune system, and at the same time, allows the bacteria to gain access to otherwise restricted nutrient sources. Yet, intracellular protection and access to nutrients comes with a price, i.e., the bacteria need to overcome cell-autonomous defense mechanisms, such as the bactericidal endocytic pathway. While a few bacteria rupture the early phagosome and escape into the host cytoplasm, most intracellular pathogens form a distinct, degradation-resistant and replication-permissive membranous compartment. Intracellular bacteria that form unique pathogen vacuoles include Legionella, Mycobacterium, Chlamydia, Simkania, and Salmonella species. In order to understand the formation of these pathogen niches on a global scale and in a comprehensive and quantitative manner, an inventory of compartment-associated host factors is required. To this end, the intact pathogen compartments need to be isolated, purified and biochemically characterized. Here, we review recent progress on the isolation and purification of pathogen-modified vacuoles and membranes, as well as their proteomic characterization by mass spectrometry and different validation approaches. These studies provide the basis for further investigations on the specific mechanisms of pathogen-driven compartment formation.
KW  - spectrometry-based proteomics
KW  - Mycobacterium tuberculosis
KW  - Chlamydia
KW  - Salmonella
KW  - bacterium Legionella pneumophila
KW  - endocytic multivesicular bodies
KW  - phagosome maturation arrest
KW  - III secretion system
KW  - endoplasmic reticulum
KW  - Chlamydia trachomatis
KW  - Simkania negevensis
KW  - intracellular bacteria
KW  - host pathogen interactions
KW  - immuno-magnetic purification
KW  - Legionella
KW  - Mycobacterium
KW  - Simkania
KW  - pathogen vacuole
Y1  - 2015
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-151823
VL  - 5
IS  - 48
ER  - 
TY  - JOUR
A1  - Subbarayal, Prema
A1  - Karunakaran, Karthika
A1  - Winkler, Ann-Cathrin
A1  - Rother, Marion
A1  - Gonzalez, Erik
A1  - Meyer, Thomas F.
A1  - Rudel, Thomas
T1  - EphrinA2 Receptor (EphA2) Is an Invasion and Intracellular Signaling Receptor for Chlamydia trachomatis
JF  - PLoS Pathogens
N2  - The obligate intracellular bacterium Chlamydia trachomatis invades into host cells to replicate inside a membrane-bound vacuole called inclusion. Multiple different host proteins are recruited to the inclusion and are functionally modulated to support chlamydial development. Invaded and replicating Chlamydia induces a long-lasting activation of the PI3 kinase signaling pathway that is required for efficient replication. We identified the cell surface tyrosine kinase EphrinA2 receptor (EphA2) as a chlamydial adherence and invasion receptor that induces PI3 kinase (PI3K) activation, promoting chlamydial replication. Interfering with binding of C. trachomatis serovar L2 (Ctr) to EphA2, downregulation of EphA2 expression or inhibition of EphA2 activity significantly reduced Ctr infection. Ctr interacts with and activates EphA2 on the cell surface resulting in Ctr and receptor internalization. During chlamydial replication, EphA2 remains active accumulating around the inclusion and interacts with the p85 regulatory subunit of PI3K to support the activation of the PI3K/Akt signaling pathway that is required for normal chlamydial development. Overexpression of full length EphA2, but not the mutant form lacking the intracellular cytoplasmic domain, enhanced PI3K activation and Ctr infection. Despite the depletion of EphA2 from the cell surface, Ctr infection induces upregulation of EphA2 through the activation of the ERK pathway, which keeps the infected cell in an apoptosis-resistant state. The significance of EphA2 as an entry and intracellular signaling receptor was also observed with the urogenital C. trachomatis-serovar D. Our findings provide the first evidence for a host cell surface receptor that is exploited for invasion as well as for receptor-mediated intracellular signaling to facilitate chlamydial replication. In addition, the engagement of a cell surface receptor at the inclusion membrane is a new mechanism by which Chlamydia subverts the host cell and induces apoptosis resistance.
KW  - membrane proteins
KW  - chlamydia infection
KW  - chlamydia trachomatis
KW  - chlamydia
KW  - HeLa cells
KW  - apoptosis
KW  - host cells
KW  - membrane receptor signaling
Y1  - 2015
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-125566
VL  - 11
IS  - 4
ER  -