Biomaterial Database

Glucose induces amphiphilic to hydrophilic conversion of a subset of glycosyl-phosphatidylinositol-anchored ectoproteins in yeast. 1995

W Bandlow, and S Wied, and G Müller

Institut für Genetik und Mikrobiologie, München, Federal Republic of Germany.

Previously, we have studied the lipolytic cleavage of a glycosyl-phosphatidylinositol (GPI)-anchored plasma membrane protein in yeast in response to a physiologically relevant external signal, i.e., transfer of spehroplasts from lactate to glucose medium (cf. Müller and Bandlow (1993) J. Cell. Biol. 122, 325-336). In the present study the glucose-induced lipolytic processing of myo-[14C]inositol-labeled total GPI proteins of the plasma membrane and in particular of two such proteins, Gas1p and Gce1p, was examined in yeast spheroplasts. It was found that a small number of GPI proteins, among them Gce1p, are readily cleaved, whereas Gas1p and the majority of the GPI proteins are relatively little affected. Glucose-induced processing of Gce1pcould be demonstrated also in intact cells. Increased GPI cleavage after exposure of cells or spheroplasts to glucose is not due to stimulation of cell surface expression of Gce1p, as the amount of total GPI-anchored Gce1p bound to plasma membranes is comparable in cells grown in glucose or lactate. In agreement with this, Brefeldin A added together with the label blocks transport of newly made Gce1p to the cell surface and, in the consequence, cleavage of labeled Gce1p in spheroplasted yeast cells. (The drug is ineffective in intact cells). On the other hand, Brefeldin A does not significantly affect glucose-induced processing of inositol-labeled Gce1p at the plasma membrane when present during the period of nutritional upshift. We discuss that addition of glucose to the cells leads to the activation of a GPI-specific phospholipase which accepts only a subset of GPI proteins as substrates. This interpretation is additionally corroborated by the finding that purified [14C]inositol-labeled Gcep1p is lipolytically cleaved when incubated with Triton X-100-insoluble membrane complexes isolated from glucose-induced but not from uninduced spheroplasts. It is concluded that the phospholipase is present in these complexes and its state of activity is preserved during the preparation. GPI anchor cleavage in yeast appears to resemble strikingly the situation in insulin-responsive adipocytes subsequently to stimulation by insulin of glucose transport into these cells.

UI	MeSH Term	Description	Entries
D008562	Membrane Glycoproteins	Glycoproteins found on the membrane or surface of cells.	Cell Surface Glycoproteins,Surface Glycoproteins,Cell Surface Glycoprotein,Membrane Glycoprotein,Surface Glycoprotein,Glycoprotein, Cell Surface,Glycoprotein, Membrane,Glycoprotein, Surface,Glycoproteins, Cell Surface,Glycoproteins, Membrane,Glycoproteins, Surface,Surface Glycoprotein, Cell,Surface Glycoproteins, Cell
D010740	Phospholipases	A class of enzymes that catalyze the hydrolysis of phosphoglycerides or glycerophosphatidates. EC 3.1.-.	Lecithinases,Lecithinase,Phospholipase
D011487	Protein Conformation	The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).	Conformation, Protein,Conformations, Protein,Protein Conformations
D011499	Protein Processing, Post-Translational	Any of various enzymatically catalyzed post-translational modifications of PEPTIDES or PROTEINS in the cell of origin. These modifications include carboxylation; HYDROXYLATION; ACETYLATION; PHOSPHORYLATION; METHYLATION; GLYCOSYLATION; ubiquitination; oxidation; proteolysis; and crosslinking and result in changes in molecular weight and electrophoretic motility.	Amino Acid Modification, Post-Translational,Post-Translational Modification,Post-Translational Protein Modification,Posttranslational Modification,Protein Modification, Post-Translational,Amino Acid Modification, Posttranslational,Post-Translational Amino Acid Modification,Post-Translational Modifications,Post-Translational Protein Processing,Posttranslational Amino Acid Modification,Posttranslational Modifications,Posttranslational Protein Processing,Protein Processing, Post Translational,Protein Processing, Posttranslational,Amino Acid Modification, Post Translational,Modification, Post-Translational,Modification, Post-Translational Protein,Modification, Posttranslational,Modifications, Post-Translational,Modifications, Post-Translational Protein,Modifications, Posttranslational,Post Translational Amino Acid Modification,Post Translational Modification,Post Translational Modifications,Post Translational Protein Modification,Post Translational Protein Processing,Post-Translational Protein Modifications,Processing, Post-Translational Protein,Processing, Posttranslational Protein,Protein Modification, Post Translational,Protein Modifications, Post-Translational
D011500	Protein Synthesis Inhibitors	Compounds which inhibit the synthesis of proteins. They are usually ANTI-BACTERIAL AGENTS or toxins. Mechanism of the action of inhibition includes the interruption of peptide-chain elongation, the blocking the A site of ribosomes, the misreading of the genetic code or the prevention of the attachment of oligosaccharide side chains to glycoproteins.	Protein Synthesis Antagonist,Protein Synthesis Antagonists,Protein Synthesis Inhibitor,Antagonist, Protein Synthesis,Antagonists, Protein Synthesis,Inhibitor, Protein Synthesis,Inhibitors, Protein Synthesis,Synthesis Antagonist, Protein,Synthesis Inhibitor, Protein
D002352	Carrier Proteins	Proteins that bind or transport specific substances in the blood, within the cell, or across cell membranes.	Binding Proteins,Carrier Protein,Transport Protein,Transport Proteins,Binding Protein,Protein, Carrier,Proteins, Carrier
D003517	Cyclopentanes	A group of alicyclic hydrocarbons with the general formula R-C5H9.	Cyclopentadiene,Cyclopentadienes,Cyclopentene,Cyclopentenes,Cyclopentane
D005947	Glucose	A primary source of energy for living organisms. It is naturally occurring and is found in fruits and other parts of plants in its free state. It is used therapeutically in fluid and nutrient replacement.	Dextrose,Anhydrous Dextrose,D-Glucose,Glucose Monohydrate,Glucose, (DL)-Isomer,Glucose, (alpha-D)-Isomer,Glucose, (beta-D)-Isomer,D Glucose,Dextrose, Anhydrous,Monohydrate, Glucose
D001692	Biological Transport	The movement of materials (including biochemical substances and drugs) through a biological system at the cellular level. The transport can be across cell membranes and epithelial layers. It also can occur within intracellular compartments and extracellular compartments.	Transport, Biological,Biologic Transport,Transport, Biologic
D012441	Saccharomyces cerevisiae	A species of the genus SACCHAROMYCES, family Saccharomycetaceae, order Saccharomycetales, known as "baker's" or "brewer's" yeast. The dried form is used as a dietary supplement.	Baker's Yeast,Brewer's Yeast,Candida robusta,S. cerevisiae,Saccharomyces capensis,Saccharomyces italicus,Saccharomyces oviformis,Saccharomyces uvarum var. melibiosus,Yeast, Baker's,Yeast, Brewer's,Baker Yeast,S cerevisiae,Baker's Yeasts,Yeast, Baker