The erythrocyte receptor for the channel-forming toxin aerolysin is a novel glycosylphosphatidyl-inositol-anchored protein

• Published in: Molecular microbiology Vol. 25; no. 2; pp. 343 - 350
• Main Authors: Cowell, S, Aschauer, W, Gruber, HJ, Nelson, K L, Buckley, J T
• Format: Journal Article
• Language: English
• Published: 01.07.1997
• Subjects: Aeromonas
• ISSN: 0950-382X

The plasma membrane of rat erythrocytes contains a 47-kDa glycoprotein that binds the channel-forming toxin aerolysin with high affinity and accounts for the sensitivity of these cells to the toxin. The receptor was purified so that its N-terminal sequence could be determined after Western blotting. The sequence did not match any sequences in the databases, indicating that the receptor is a novel erythrocyte surface protein. However, it exhibited considerable homology to the N-termini of a group of membrane proteins that are thought to be involved in ADP-ribosyl transfer reactions. A common property of these proteins is that they are attached to plasma membranes by C-terminal glycosylphosphatidyl-inositol (GPI) anchors. The aerolysin receptor was shown to be anchored in the same way by treating rat erythrocytes with phosphatidylinositol-specific phospholipase C. This caused the selective release of the receptor and a reduction in the rodent cells' sensitivity to aerolysin. Human and bovine erythrocytes were shown to contain an aerolysin-binding protein with similar properties to the rat erythrocyte receptor. Proteins with GPI anchors are thought to have unusually high lateral mobility, and this may be an advantage for a toxin, such as aerolysin, which must oligomerize after binding to become insertion competent.