title: Cytokeratin 8 interacts with clumping factor B: a new possible virulence factor target.
abstract: Staphylococcus aureus is a human pathogen of growing clinical significance, owing to its increasing levels of resistance to most antibiotics. Infections range from mild wound infections to severe infections such as endocarditis, osteomyelitis and septic shock. Adherence of S. aureus to human host cells is an important step, leading to colonization and infection. Adherence is mediated by a multiplicity of proteins expressed on the bacterial surface, including clumping factor B. In this study, we aimed to identify new targets of clumping factor B in human keratinocytes by undertaking a genome-wide yeast two-hybrid screen of a human keratinocyte cDNA library. We show that clumping factor B is capable of binding cytokeratin 8 (CK8), a type II cytokeratin. Using a domain-mapping strategy we identified amino acids 437-464 as necessary for this interaction. Recombinantly expressed fragments of both proteins were used in pull-down experiments and confirmed the yeast two-hybrid studies. Analysis with S. aureus strain Newman deficient in clumping factor B showed the clumping factor B-dependence of the interaction with CK8. We postulate that the clumping factor B-CK8 interaction is a novel factor in S. aureus infections.
authors.affiliation: Procomcure Biotech GmbH, Hafenstrasse 47-51, A-4020 Linz, Austria.|Division of Molecular Dermatology, Department of Dermatology, University Hospital, Paracelsus Medical University, 5020 Salzburg, Austria.
authors.forename: M
authors.initials: M
authors.lastname: Haim
authors.affiliation: Division of Molecular Dermatology, Department of Dermatology, University Hospital, Paracelsus Medical University, 5020 Salzburg, Austria.
authors.forename: A
authors.initials: A
authors.lastname: Trost
authors.affiliation: Department of Cell Biology, University of Salzburg, 5020 Salzburg, Austria.|Division of Molecular Dermatology, Department of Dermatology, University Hospital, Paracelsus Medical University, 5020 Salzburg, Austria.
authors.forename: C J
authors.initials: CJ
authors.lastname: Maier
authors.affiliation: Department of Molecular Biology, University of Salzburg, 5020 Salzburg, Austria.
authors.forename: G
authors.initials: G
authors.lastname: Achatz
authors.affiliation: Department of Molecular Biology, University of Salzburg, 5020 Salzburg, Austria.
authors.forename: S
authors.initials: S
authors.lastname: Feichtner
authors.affiliation: Division of Molecular Dermatology, Department of Dermatology, University Hospital, Paracelsus Medical University, 5020 Salzburg, Austria.
authors.forename: H
authors.initials: H
authors.lastname: Hintner
authors.affiliation: Procomcure Biotech GmbH, Hafenstrasse 47-51, A-4020 Linz, Austria.|Division of Molecular Dermatology, Department of Dermatology, University Hospital, Paracelsus Medical University, 5020 Salzburg, Austria.
authors.forename: J W
authors.initials: JW
authors.lastname: Bauer
authors.affiliation: Procomcure Biotech GmbH, Hafenstrasse 47-51, A-4020 Linz, Austria.|Division of Molecular Dermatology, Department of Dermatology, University Hospital, Paracelsus Medical University, 5020 Salzburg, Austria.
authors.forename: K
authors.initials: K
authors.lastname: Önder
mesh_terms: D018829:Adhesins, Bacterial / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D002460:Cell Line; D006801:Humans; D053533:Keratin-8 / Q000235:genetics / Q000378:metabolism*; D015603:Keratinocytes / Q000378:metabolism / Q000382:microbiology; D008969:Molecular Sequence Data; D011485:Protein Binding; D013203:Staphylococcal Infections / Q000235:genetics / Q000378:metabolism* / Q000382:microbiology; D013211:Staphylococcus aureus / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity; D020798:Two-Hybrid System Techniques; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D018829:Adhesins, Bacterial; D053533:Keratin-8; D037521:Virulence Factors; C434058:clfB protein, Staphylococcus aureus