Glycosylphosphatidylinositol -binding protein

Mammalian PLDs are now the subject of intense interest as they appear to be intimately involved in signal transduction (M. McDermott, 2004 G.M. Jenkins, 2005). Two mammalian PLDs have been identified and these contain several domains often associated with signal transduction proteins including a PH domain and a separate phosphatidylinositol-bis-phosphate-binding domain. PLC and PLD that act on glycosylphosphatidylinositol-anchored proteins on the cell surface are of growing importance and are discussed in Chapter 2. 

Fig. 4. Model showing the interactions between the endothelial cell surface, triacylglycerol-rich lipoproteins, apo C2, and lipoprotein lipase (LPL). Two LPL molecules are shown reacting with the same VLDL particle. These are representative of the multiple LPLs that probably react with each triacylglycerol-rich lipoprotein. The location of the recently identified glycosylphosphatidylinositol-anchored HDL binding protein-1 within the substrate-lipase complex has not yet been identified.

Molecular targets have been elucidated for Dm-AMPl and Rs-AFP2. Dm-AMPl was found to bind plasma membranes from Neurospora crassa and Saccharomyces cerevisiae in a saturable manner and it competed with closely related defensins for binding. Mutational studies with S. cerevisiae identified lipid raffs containing sphingolipids as a molecular target " while glycosylphosphatidylinositol (GPI)-anchored proteins could be... 

Glycosylphosphatidylinositols (GPI anchors 14) are a class of naturally occu-ring glycophospholipids that do not only bind the C-termini of membrane protein but also mediate signal transduction. Several papers have been devoted to their syntheses. Most of them have a structure related to 14 (with various side-chains that are species-specific) but some yeast GPI have been reported to... 

Ascidian sperm glycosylphosphatidylinositol-anchored CRISP-like protein as a binding partner for an allorecognizable sperm receptor on the vitelline coat. J Biol Chem 283(31) 21725-21733. 

N-CAM is particularly well characterized. It exhibits homophilic binding (binds to N-CAMs on other cells), and it exists in several isoforms. The largest isoforms of N-CAM are transmembrane proteins (M, 180,000 and 140,000). Smaller isoforms (M, 120,000-125,000) are located on the membrane surface, where they are attached by a glycosylphosphatidylinositol anchor, whereas the smallest isoforms M 115,000) are found as soluble proteins,... 

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