title: Streptococcus agalactiae CAMP factor binds to GPI-anchored proteins.
abstract: CAMP factor (protein B) is a pore-forming protein secreted by Streptococcus agalactiae. It causes lysis of sheep red blood cells when these have been sensitized with staphylococcal sphingomyelinase. We here show that CAMP factor binds to GPI-anchored proteins, and that this interaction involves the carbohydrate core of the GPI-anchor. Enzymatic cleavage of GPI-anchors with phosphatidylinositol-specific phospholipase C strongly reduces the sensitivity of erythrocytes to CAMP factor. Incorporation of alkaline phosphatase, a model GPI-anchored protein, into liposome membranes renders the latter susceptible to permeabilization by CAMP factor. GPI-anchored proteins therefore function as cellular receptors for CAMP factor.
authors.affiliation: Department of Chemistry, University of Waterloo, N2L 3G1 Waterloo, ON, Canada.
authors.forename: Shenhui
authors.initials: S
authors.lastname: Lang
authors.forename: Jie
authors.initials: J
authors.lastname: Xue
authors.forename: Zhongwu
authors.initials: Z
authors.lastname: Guo
authors.forename: Michael
authors.initials: M
authors.lastname: Palmer
mesh_terms: D001426:Bacterial Proteins / Q000097:blood / Q000378:metabolism*; D019286:Endopeptidase K / Q000378:metabolism; D004910:Erythrocyte Membrane / Q000378:metabolism*; D004912:Erythrocytes / Q000378:metabolism; D017261:Glycosylphosphatidylinositols / Q000097:blood / Q000737:chemistry / Q000378:metabolism*; D006460:Hemolysin Proteins / Q000097:blood / Q000378:metabolism*; D006461:Hemolysis; D008081:Liposomes / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism*; D043265:Phosphatidylinositol Diacylglycerol-Lyase / Q000378:metabolism; D054801:Phosphoinositide Phospholipase C; D011485:Protein Binding; D013292:Streptococcus agalactiae / Q000378:metabolism* / Q000472:pathogenicity
chemical_list: D001426:Bacterial Proteins; C039092:CAMP protein, Streptococcus; D017261:Glycosylphosphatidylinositols; D006460:Hemolysin Proteins; D008081:Liposomes; D008565:Membrane Proteins; D054801:Phosphoinositide Phospholipase C; D019286:Endopeptidase K; D043265:Phosphatidylinositol Diacylglycerol-Lyase