AUTHOR=Junemann Johannes , Just Ingo , Gerhard Ralf , Pich Andreas 

TITLE=Quantitative Phosphoproteome Analysis of Clostridioides difficile Toxin B Treated Human Epithelial Cells

JOURNAL=Frontiers in Microbiology

VOLUME=9

YEAR=2018

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2018.03083

DOI=10.3389/fmicb.2018.03083

ISSN=1664-302X

ABSTRACT=<p>The large clostridial glucosylating toxin B (TcdB) is a major virulence factor of the nosocomial pathogen <italic>Clostridioides difficile</italic>. TcdB inhibits small GTPases by glucosylation leading to impaired downstream signaling. TcdB also possesses a glucosyltransferase independent effect described as pyknosis. To elucidate the impact of TcdB and its glucosylation-inactive mutant TcdB<sub>NXN</sub> on the kinome of human cells, SILAC labeled HEp-2 cells were treated with 2 nM TcdB for 8 h. Phosphopeptides were enriched using SCX chromatography, IMAC and TiO<sub>2</sub> followed shotgun mass spectrometry analysis. Overall 4,197 phosphopeptides were identified; more than 1,200 phosphosites responded to treatment with TcdB or TcdB<sub>NXN</sub>. The data suggested that predominantly stress-activated MAPK-dependent signaling pathways were triggered by toxin B treatment.</p>