Glycosyl Phosphatidyl Inositol Anchors

Udeniriend, S., and Kodukola, K. 1995. How glycosyl-phosphatidyl-inositol-anchored membrane proteins are made. Anmi. Rev Bittchem. 64 563—.591. 

The cells of D. discoideum harbor the machinery for post-translational protein modifications such as phosphorylation, acylation, formation of glycosyl phosphatidyl-inositol anchors, and, in particular, O-hnked and N-hnked glycosylation [90, 91]. 

Pekari K, Schmidt RR. A variable concept for the preparation of branched glycosyl phosphatidyl inositol anchors. J Org Chem 2003 68 1295-1308. 

Roudier, E, Fernandes, A.G., Fujita, M., Himmelspach, R., Bomer, G.H.H., Schindelman, G., Song, S., Baskin, T.I., Dupree, R, Wasteneys, G.O., and Benfey, P.N. 2005. CX)BRA, an Arabidopsis extracellular glycosyl-phosphatidyl inositol-anchored protein, specifically controls highly anisotropic expansion through its involvement in cellulose microfibril orientation. The Plant Cell 17 1749-1783. 

Fig. 3.15. Typical strucutre of a glycosyl phosphatidyl inositol (GPI) anchor. Ins inositol GlcN 2 -amino, 2 -deoxy-glucose Man mannose Etn Ethanolamine, P phosphate.

Loertscher, R., and Lavery, P., 2002, The role of glycosyl phosphatidyl inositol (gpi)-anchored cell surface proteins inT-cell activation. Transpl. Immunol. 9 93-96. 

The presence of peak 2, corresponding to elution of the mannoprotein responsible for tartrate stabilization, confirms that the bond is covalent. Some of the mannoproteins that share covalent bonds with glucane also have a special type of glycosylation, leading to a glycosyl-phosphatidyl-inositol (GPI). The use of a mutant strain (FBYII), deficient in GPI-anchored mannoproteins when cnltnred at 37°C (FBYII-37), showed that the mannoproteins responsible for tartrate stabilization had this type of glycosylation. Two types of mannoprotein extracts were obtained by enzyme hydrolysis of yeast cell walls (FBYII), cultmed at 24°C or 37°C. 

Immunosuppression in the definitive and intermediate hosts of Schistosoma mansoni is mediated by the release of immunoreactive peptides as 13-endorphin (Duvaux-Miret et al. 1992). The release of the glycosyl-phosphatidyl-inositol (GPI)-anchored glycoproteins may contribute to immune evasion of Schistosoma mansoni (Sauma and Strand 1990). 

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