TY  - JOUR
A1  - Stelzner, Kathrin
A1  - Winkler, Ann-Cathrin
A1  - Liang, Chunguang
A1  - Boyny, Aziza
A1  - Ade, Carsten P.
A1  - Dandekar, Thomas
A1  - Fraunholz, Martin J.
A1  - Rudel, Thomas
T1  - Intracellular Staphylococcus aureus Perturbs the Host Cell Ca\(^{2+}\) Homeostasis To Promote Cell Death
JF  - mBio
N2  - The opportunistic human pathogen Staphylococcus aureus causes serious infectious diseases that range from superficial skin and soft tissue infections to necrotizing pneumonia and sepsis. While classically regarded as an extracellular pathogen, S. aureus is able to invade and survive within human cells. Host cell exit is associated with cell death, tissue destruction, and the spread of infection. The exact molecular mechanism employed by S. aureus to escape the host cell is still unclear. In this study, we performed a genome-wide small hairpin RNA (shRNA) screen and identified the calcium signaling pathway as being involved in intracellular infection. S. aureus induced a massive cytosolic Ca\(^{2+}\) increase in epithelial host cells after invasion and intracellular replication of the pathogen. This was paralleled by a decrease in endoplasmic reticulum Ca\(^{2+}\) concentration. Additionally, calcium ions from the extracellular space contributed to the cytosolic Ca2+ increase. As a consequence, we observed that the cytoplasmic Ca\(^{2+}\) rise led to an increase in mitochondrial Ca\(^{2+}\) concentration, the activation of calpains and caspases, and eventually to cell lysis of S. aureus-infected cells. Our study therefore suggests that intracellular S. aureus disturbs the host cell Ca\(^{2+}\) homeostasis and induces cytoplasmic Ca\(^{2+}\) overload, which results in both apoptotic and necrotic cell death in parallel or succession.

IMPORTANCE Despite being regarded as an extracellular bacterium, the pathogen Staphylococcus aureus can invade and survive within human cells. The intracellular niche is considered a hideout from the host immune system and antibiotic treatment and allows bacterial proliferation. Subsequently, the intracellular bacterium induces host cell death, which may facilitate the spread of infection and tissue destruction. So far, host cell factors exploited by intracellular S. aureus to promote cell death are only poorly characterized. We performed a genome-wide screen and found the calcium signaling pathway to play a role in S. aureus invasion and cytotoxicity. The intracellular bacterium induces a cytoplasmic and mitochondrial Ca\(^{2+}\) overload, which results in host cell death. Thus, this study first showed how an intracellular bacterium perturbs the host cell Ca\(^{2+}\) homeostasis."
KW  - Staphylococcus aureus
KW  - calcium signaling pathway
KW  - cell death
KW  - facultatively intracellular pathogens
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-231448
VL  - 11
ER  - 
TY  - JOUR
A1  - Whisnant, Adam W.
A1  - Jürges, Christopher S.
A1  - Hennig, Thomas
A1  - Wyler, Emanuel
A1  - Prusty, Bhupesh
A1  - Rutkowski, Andrzej J.
A1  - L'hernault, Anne
A1  - Djakovic, Lara
A1  - Göbel, Margarete
A1  - Döring, Kristina
A1  - Menegatti, Jennifer
A1  - Antrobus, Robin
A1  - Matheson, Nicholas J.
A1  - Künzig, Florian W. H.
A1  - Mastrobuoni, Guido
A1  - Bielow, Chris
A1  - Kempa, Stefan
A1  - Liang, Chunguang
A1  - Dandekar, Thomas
A1  - Zimmer, Ralf
A1  - Landthaler, Markus
A1  - Grässer, Friedrich
A1  - Lehner, Paul J.
A1  - Friedel, Caroline C.
A1  - Erhard, Florian
A1  - Dölken, Lars
T1  - Integrative functional genomics decodes herpes simplex virus 1
JF  - Nature Communications
N2  - The predicted 80 open reading frames (ORFs) of herpes simplex virus 1 (HSV-1) have been intensively studied for decades. Here, we unravel the complete viral transcriptome and translatome during lytic infection with base-pair resolution by computational integration of multi-omics data. We identify a total of 201 transcripts and 284 ORFs including all known and 46 novel large ORFs. This includes a so far unknown ORF in the locus deleted in the FDA-approved oncolytic virus Imlygic. Multiple transcript isoforms expressed from individual gene loci explain translation of the vast majority of ORFs as well as N-terminal extensions (NTEs) and truncations. We show that NTEs with non-canonical start codons govern the subcellular protein localization and packaging of key viral regulators and structural proteins. We extend the current nomenclature to include all viral gene products and provide a genome browser that visualizes all the obtained data from whole genome to single-nucleotide resolution. Here, using computational integration of multi-omics data, the authors provide a detailed transcriptome and translatome of herpes simplex virus 1 (HSV-1), including previously unidentified ORFs and N-terminal extensions. The study also provides a HSV-1 genome browser and should be a valuable resource for further research.
KW  - infected-cell protein
KW  - messenger RNA
KW  - binding protein
KW  - type 1
KW  - identification
KW  - ICP27
KW  - translation
KW  - expression
KW  - sequence
KW  - domain
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-229884
VL  - 11
ER  -