The glycosylphosphatidylinositol-anchored surface glycoprotein Thy-1 is a receptor for the channel-forming toxin aerolysin.
Aerolysin is a channel-forming protein secreted by virulent Aeromonas spp. Some eucaryotic cells, including T-lymphocytes, are sensitive to very low concentrations of the toxin (<10(-9) M). Here we show that aerolysin binds selectively and with high affinity to the glycosylphosphatidylinositol (GPI)-anchored surface protein Thy-1, which is found on T-lymphocyte populations as well as in brain. Less than 1 ng of purified Thy-1 could be detected by probing Western blots with the toxin. Mutant T-cell lines that lack the ability to add GPI anchors to Thy-1 and other surface proteins were much less sensitive to aerolysin, as were wild-type cells that were pretreated with phosphatidylinositol-specific phospholipase C to remove GPI-anchored proteins. Phosphatidylcholine/cholesterol liposomes containing purified Thy-1 in their membranes were much more sensitive to aerolysin than protein-free liposomes.
Nelson
K L
KL
Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8W 3P6, Canada.
Raja
S M
SM
Buckley
J T
JT
D000818:Animals; D001427:Bacterial Toxins / Q000378:metabolism* / Q000494:pharmacology; D001921:Brain / Q000378:metabolism; D017261:Glycosylphosphatidylinositols / Q000378:metabolism*; D006460:Hemolysin Proteins / Q000378:metabolism; D007473:Ion Channels / Q000502:physiology; D007700:Kinetics; D008081:Liposomes; D008223:Lymphoma; D051379:Mice; D008970:Molecular Weight; D009928:Organ Specificity; D043265:Phosphatidylinositol Diacylglycerol-Lyase; D054801:Phosphoinositide Phospholipase C; D010727:Phosphoric Diester Hydrolases; D052899:Pore Forming Cytotoxic Proteins; D013601:T-Lymphocytes; D018800:Thy-1 Antigens / Q000378:metabolism*; D013945:Thymoma; D013950:Thymus Gland / Q000378:metabolism; D013953:Thymus Neoplasms; D014407:Tumor Cells, Cultured
D001427:Bacterial Toxins; D017261:Glycosylphosphatidylinositols; D006460:Hemolysin Proteins; D007473:Ion Channels; D008081:Liposomes; D052899:Pore Forming Cytotoxic Proteins; D018800:Thy-1 Antigens; C032676:aerolysin; D010727:Phosphoric Diester Hydrolases; D054801:Phosphoinositide Phospholipase C; D043265:Phosphatidylinositol Diacylglycerol-Lyase