On The Presence of Glycosylphosphatidylinositol-Anchored Proteins in Plants

Abstract

There are now more than 100 different proteins known to be attached to the cell surface of animal or yeast cells by a glycosylphosphatidylinositol(GPI) anchor [1]. The structure of these anchoring units (Fig 1) is relatively highly conserved, although additional sugar moieties are sometimes attached to the basic oligoglycan backbone, and the diacylglycerol lipid unit is in certain molecules replaced by an alkyl,acyl-glycerol or a ceramide structure. Among the more familiar proteins now known to be GPI-anchored are alkaline phosphatase, acetylcholinesterase, and the variable surface glycoprotein coating the surface of trypanosomes. Surprisingly, there have been no reports of GPI-anchored proteins in plants. Because my laboratory has an ongoing project to study the GPI-anchored proteins of the protozoan Tetrahymena, we have been able to apply this technology in a search for these proteins in higher plants.