Assembly of staphylococcal leukocidin into a pore-forming oligomer on detergent-resistant membrane microdomains, lipid rafts, in human polymorphonuclear leukocytes.
Staphylococcal leukocidin (Luk) consists of LukS and LukF, which cooperatively lyse human polymorphonuclear leukocytes (HPMNLs), monocytes, and macrophages. Here we found that LukS and LukF assembles into hetero-oligomeric pore complexes on the detergent-resistant membrane microdomains, lipid rafts of HPMNLs. When HPMNLs were treated with LukS alone, 24% of the added LukS was localized in lipid rafts. Furthermore, in HPMNLs treated with both LukS and LukF simultaneously, about 90% of high molecular-mass complexes of 100 kDa, which consists of LukS and LukF, were detected in the lipid raft fractions. In contrast, in HPMNLs treated with LukF alone, LukF was not localized in lipid rafts despite binding to the target cell membranes. Ten mM methyl-beta-cyclodextrin, a dysfunctioning agent of lipid rafts, completely inhibited assembly of Luk on lipid rafts, and resulted in null leukocytolytic activity of Luk. Hence, we concluded that assembly of LukS and LukF into the pore-complex occurs in lipid rafts in HPMNLs and that LukF can bind to LukS, which had already bound to lipid rafts, to assemble into hetero-oligomers.
Nishiyama
Akihito
A
Laboratory of Applied Microbiology, Department of Microbial Biotechnology, Graduate School of Agricultural Science, Tohoku University.
Kaneko
Jun
J
Harata
Masahiko
M
Kamio
Yoshiyuki
Y
D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D003902:Detergents / Q000494:pharmacology*; D006801:Humans; D007956:Leukocidins; D021962:Membrane Microdomains / Q000187:drug effects* / Q000378:metabolism*; D009504:Neutrophils / Q000166:cytology*; D013211:Staphylococcus aureus / Q000378:metabolism*; D020798:Two-Hybrid System Techniques
D001426:Bacterial Proteins; D003902:Detergents; D007956:Leukocidins; C108483:leukocidin S-component protein, Staphylococcus; C074300:LukF protein, Staphylococcus aureus