title: Staphylococcus aureus: Staphylokinase.
abstract: Staphylokinase is a 136 aa long bacteriophage encoded protein expressed by lysogenic strains of Staphylococcus aureus. Present understanding of the role of staphylokinase during bacterial infection is based on its interaction with the host proteins, alpha-defensins and plasminogen. alpha-Defensins are bactericidal peptides originating from human neutrophils. Binding of staphylokinase to alpha-defensins abolishes their bactericidal properties, which makes staphylokinase a vital tool for staphylococcal resistance to host innate immunity. Complex binding between staphylokinase and plasminogen results in the formation of active plasmin, a broad-spectrum proteolytic enzyme facilitating bacterial penetration into the surrounding tissues. We have recently shown high levels of staphylokinase expression in clinical isolates of skin and mucosal origin and relative low levels in isolates invading internal organs. These findings are supported by sepsis studies using isogenic S. aureus strains demonstrating increased bacterial load in the absence of staphylokinase production. Our observations indicate that staphylokinase favours symbiosis of staphylococci with the host that makes it an important colonization factor.
authors.affiliation: Department of Rheumatology and Inflammation Research, Sahlgrenska University Hospital, Guldhedsgatan 10, SE-41346 Göteborg, Sweden. martia.bokarewa@rheuma.gu.se
authors.forename: Maria I
authors.initials: MI
authors.lastname: Bokarewa
authors.forename: Tao
authors.initials: T
authors.lastname: Jin
authors.forename: Andrej
authors.initials: A
authors.lastname: Tarkowski
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000378:metabolism*; D006801:Humans; D008666:Metalloendopeptidases / Q000378:metabolism*; D009092:Mucous Membrane / Q000378:metabolism / Q000382:microbiology; D010958:Plasminogen / Q000378:metabolism; D011485:Protein Binding; D012867:Skin / Q000378:metabolism / Q000382:microbiology; D013203:Staphylococcal Infections / Q000201:enzymology* / Q000382:microbiology; D013211:Staphylococcus aureus / Q000201:enzymology* / Q000472:pathogenicity / Q000821:virology; D037521:Virulence Factors / Q000378:metabolism*; D023084:alpha-Defensins / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D037521:Virulence Factors; D023084:alpha-Defensins; D010958:Plasminogen; D008666:Metalloendopeptidases; C022653:auR protein, Staphylococcus aureus