Biomaterial Database

Topological orientation of mitochondrial GDPmannose: dolichyl-monophosphate mannosyltransferase in the outer membrane. 1989

F Gasnier, and P Louisot, and O Gateau-Roesch

University of Lyon, Department of Biochemistry, Oullins, France.

Previous studies have shown the existence of an autonomous mitochondrial GDPmannose:dolichylmonophosphate mannosyltransferase, located in mitochondrial outer membrane of liver cells. As nothing is known about glycosylation sites in mitochondria, we have investigated the topological orientation of this enzyme in intact mitochondria, using controlled proteolysis with trypsin. Mitochondria were purified sequentially by mild ultrasonic treatment and sucrose density gradient. Purity and homogeneity of mitochondrial fraction were assessed by electron microscopy and specific marker enzymes measures. Our data provide evidence for a mitochondrial GDPmannose:dolichylmonophosphate mannosyltransferase facing the cytoplasmic side of the outer membrane. However, the exposure of this enzyme to the water phase has been shown to be dependent on the ionic strength of the environment.

UI	MeSH Term	Description	Entries
D007425	Intracellular Membranes	Thin structures that encapsulate subcellular structures or ORGANELLES in EUKARYOTIC CELLS. They include a variety of membranes associated with the CELL NUCLEUS; the MITOCHONDRIA; the GOLGI APPARATUS; the ENDOPLASMIC RETICULUM; LYSOSOMES; PLASTIDS; and VACUOLES.	Membranes, Intracellular,Intracellular Membrane,Membrane, Intracellular
D008364	Mannosyltransferases	Enzymes that catalyze the transfer of mannose from a nucleoside diphosphate mannose to an acceptor molecule which is frequently another carbohydrate. The group includes EC 2.4.1.32, EC 2.4.1.48, EC 2.4.1.54, and EC 2.4.1.57.	Mannosyltransferase
D008815	Mice, Inbred Strains	Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations, or by parent x offspring matings carried out with certain restrictions. All animals within an inbred strain trace back to a common ancestor in the twentieth generation.	Inbred Mouse Strains,Inbred Strain of Mice,Inbred Strain of Mouse,Inbred Strains of Mice,Mouse, Inbred Strain,Inbred Mouse Strain,Mouse Inbred Strain,Mouse Inbred Strains,Mouse Strain, Inbred,Mouse Strains, Inbred,Strain, Inbred Mouse,Strains, Inbred Mouse
D008930	Mitochondria, Liver	Mitochondria in hepatocytes. As in all mitochondria, there are an outer membrane and an inner membrane, together creating two separate mitochondrial compartments: the internal matrix space and a much narrower intermembrane space. In the liver mitochondrion, an estimated 67% of the total mitochondrial proteins is located in the matrix. (From Alberts et al., Molecular Biology of the Cell, 2d ed, p343-4)	Liver Mitochondria,Liver Mitochondrion,Mitochondrion, Liver
D009702	Nucleoside Diphosphate Sugars		Diphosphate Sugars, Nucleoside,Sugars, Nucleoside Diphosphate
D009994	Osmolar Concentration	The concentration of osmotically active particles in solution expressed in terms of osmoles of solute per liter of solution. Osmolality is expressed in terms of osmoles of solute per kilogram of solvent.	Ionic Strength,Osmolality,Osmolarity,Concentration, Osmolar,Concentrations, Osmolar,Ionic Strengths,Osmolalities,Osmolar Concentrations,Osmolarities,Strength, Ionic,Strengths, Ionic
D002458	Cell Fractionation	Techniques to partition various components of the cell into SUBCELLULAR FRACTIONS.	Cell Fractionations,Fractionation, Cell,Fractionations, Cell
D002499	Centrifugation, Density Gradient	Separation of particles according to density by employing a gradient of varying densities. At equilibrium each particle settles in the gradient at a point equal to its density. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	Centrifugations, Density Gradient,Density Gradient Centrifugation,Density Gradient Centrifugations,Gradient Centrifugation, Density,Gradient Centrifugations, Density
D004789	Enzyme Activation	Conversion of an inactive form of an enzyme to one possessing metabolic activity. It includes 1, activation by ions (activators); 2, activation by cofactors (coenzymes); and 3, conversion of an enzyme precursor (proenzyme or zymogen) to an active enzyme.	Activation, Enzyme,Activations, Enzyme,Enzyme Activations
D006155	Guanosine Diphosphate Mannose	A nucleoside diphosphate sugar which can be converted to the deoxy sugar GDPfucose, which provides fucose for lipopolysaccharides of bacterial cell walls. Also acts as mannose donor for glycolipid synthesis.	GDP Mannose,Guanosine Diphosphomannose,Guanosine Pyrophosphate Mannose,Diphosphate Mannose, Guanosine,Diphosphomannose, Guanosine,Mannose, GDP,Mannose, Guanosine Diphosphate,Mannose, Guanosine Pyrophosphate,Pyrophosphate Mannose, Guanosine