XVI International Botanical Congess

AGPs are a class of cell surface and secreted plant proteoglycans implicated in a diverse range of functions including plant growth and development. A subgroup of AGPs, classical AGPs, are distinguished by a protein backbone comprising a hydroxyproline-rich region, the likely site of O-glycosylation, and a C-terminal glycosylphosphatidyl-inositol (GPI) anchor. The GPI anchor of PcAGP1 (pear cell suspension culture) has the minimal core glycan structure found in other eukaryotes and a phosphoceramide lipid composed of phytosphingosine and tetracosanoic acid. The GPI anchor provides a mechanism for the regulated release of AGPs from the plasma membrane. The function of classical AGPs is being addressed through the identification of mutants in Arabidopsis.