title: Dissecting the role of ADAM10 as a mediator of Staphylococcus aureus α-toxin action.
abstract: Staphylococcus aureus is a leading cause of bacterial infections in humans, including life-threatening diseases such as pneumonia and sepsis. Its small membrane-pore-forming α-toxin is considered an important virulence factor. By destroying cell-cell contacts through cleavage of cadherins, the metalloproteinase ADAM10 (a disintegrin and metalloproteinase 10) critically contributes to α-toxin-dependent pathology of experimental S. aureus infections in mice. Moreover, ADAM10 was proposed to be a receptor for α-toxin. However, it is unclear whether the catalytic activity or specific domains of ADAM10 are involved in mediating binding and/or subsequent cytotoxicity of α-toxin. Also, it is not known how α-toxin triggers ADAM10's enzymatic activity, and whether ADAM10 is invariably required for all α-toxin action on cells. In the present study, we show that efficient cleavage of the ADAM10 substrate epithelial cadherin (E-cadherin) requires supra-cytotoxic concentrations of α-toxin, leading to significant increases in intracellular [Ca(2+)]; the fall in cellular ATP levels, typically following membrane perforation, became observable at far lower concentrations. Surprisingly, ADAM10 was dispensable for α-toxin-dependent xenophagic targeting of S. aureus, whereas a role for α-toxin attack on the plasma membrane was confirmed. The catalytic site of ADAM10, furin cleavage site, cysteine switch and intracellular domain of ADAM10 were not required for α-toxin binding and subsequent cytotoxicity. In contrast, an essential role for the disintegrin domain and the prodomain emerged. Thus, co-expression of the prodomain with prodomain-deficient ADAM10 reconstituted binding of α-toxin and susceptibility of ADAM10-deficient cells. The results of the present study may help to inform structural analyses of α-toxin-ADAM10 interactions and to design novel strategies to counteract S. aureus α-toxin action.
authors.affiliation: Institute of Medical Microbiology and Hygiene, University Medical Center, Johannes Gutenberg-University Mainz, Hochhaus am Augustusplatz, D-55131 Mainz, Germany.
authors.forename: Gisela
authors.initials: G
authors.lastname: von Hoven
authors.affiliation: Institute of Medical Microbiology and Hygiene, University Medical Center, Johannes Gutenberg-University Mainz, Hochhaus am Augustusplatz, D-55131 Mainz, Germany.
authors.forename: Amable J
authors.initials: AJ
authors.lastname: Rivas
authors.affiliation: Institute of Medical Microbiology and Hygiene, University Medical Center, Johannes Gutenberg-University Mainz, Hochhaus am Augustusplatz, D-55131 Mainz, Germany.
authors.forename: Claudia
authors.initials: C
authors.lastname: Neukirch
authors.affiliation: Institute of Medical Microbiology and Hygiene, University Medical Center, Johannes Gutenberg-University Mainz, Hochhaus am Augustusplatz, D-55131 Mainz, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Klein
authors.affiliation: Institute of Medical Microbiology and Hygiene, University Medical Center, Johannes Gutenberg-University Mainz, Hochhaus am Augustusplatz, D-55131 Mainz, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Hamm
authors.affiliation: Institute of Medical Microbiology and Hygiene, University Medical Center, Johannes Gutenberg-University Mainz, Hochhaus am Augustusplatz, D-55131 Mainz, Germany.
authors.forename: Qianqian
authors.initials: Q
authors.lastname: Qin
authors.affiliation: Institute of Medical Microbiology and Hygiene, University Medical Center, Johannes Gutenberg-University Mainz, Hochhaus am Augustusplatz, D-55131 Mainz, Germany.
authors.forename: Martina
authors.initials: M
authors.lastname: Meyenburg
authors.affiliation: Institute of Medical Microbiology and Hygiene, University Medical Center, Johannes Gutenberg-University Mainz, Hochhaus am Augustusplatz, D-55131 Mainz, Germany.
authors.forename: Sabine
authors.initials: S
authors.lastname: Füser
authors.affiliation: Institute of Biochemistry, University of Kiel, Olshausenstraße 40, D-24098 Kiel, Germany.
authors.forename: Paul
authors.initials: P
authors.lastname: Saftig
authors.affiliation: Institute of Molecular Biophysics, Faculty of Biology, Johannes Gutenberg-University Mainz, Jakob Welder Weg 26, D-55128 Mainz, Germany.
authors.forename: Nadja
authors.initials: N
authors.lastname: Hellmann
authors.affiliation: Institute of Pharmacy and Biochemistry, Johannes Gutenberg-University Mainz, Johann-Joachim Becherweg 30, D-55128 Mainz, Germany postina@uni-mainz.de husmann@uni-mainz.de.
authors.forename: Rolf
authors.initials: R
authors.lastname: Postina
authors.affiliation: Institute of Medical Microbiology and Hygiene, University Medical Center, Johannes Gutenberg-University Mainz, Hochhaus am Augustusplatz, D-55131 Mainz, Germany postina@uni-mainz.de husmann@uni-mainz.de.
authors.forename: Matthias
authors.initials: M
authors.lastname: Husmann
mesh_terms: D000072197:ADAM10 Protein / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D001427:Bacterial Toxins / Q000737:chemistry / Q000378:metabolism*; D015820:Cadherins / Q000235:genetics / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D020134:Catalytic Domain / Q000235:genetics; D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured; D006460:Hemolysin Proteins / Q000737:chemistry / Q000378:metabolism*; D051379:Mice; D018345:Mice, Knockout; D011485:Protein Binding; D013203:Staphylococcal Infections / Q000378:metabolism; D013211:Staphylococcus aureus / Q000378:metabolism* / Q000472:pathogenicity
chemical_list: D001427:Bacterial Toxins; D015820:Cadherins; D006460:Hemolysin Proteins; C021091:staphylococcal alpha-toxin; D000072197:ADAM10 Protein; D002118:Calcium
keywords: E-cadherin; Staphylococcus aureus α-toxin; a disintegrin and metalloproteinase 10 (ADAM10); calcium; cytotoxicity; microtubule-associated protein 1A/1B light chain 3 (LC3)