The nuclear associated endoplasmic reticulum and membrane biogenesis in MPC-11 cells. 1988

I F Pryme
Department of Biochemistry, University of Bergen, Norway.

The incorporation of 3H-glucosamine, 3H-choline and 14C-fucose into subcellular fractions of MPC-11 cells was studied. After a 20 min period of labelling with both 3H-glucosamine and 3H-choline, greatest incorporation was observed in nuclear-associated endoplasmic reticulum (NER). 14C-fucose, however, was incorporated to a greater extent in endoplasmic reticulum (ER) membranes. Pulse-chase experiments with 3H-glucosamine showed a loss of radioactivity from NER and a simultaneous increase in the ER fraction. In comparison to NER, ER membranes were poorly labeled with 3H-glucosamine after a 20 min pulse. Following a 2 h incubation there was a 12 fold increase in radioactivity in ER membranes in comparison to a 1.2 fold increase in NER. There were no individual differences between subfractions of ER membranes with respect to 3H-glucosamine content after the pulse, or following the 2 h incubation. The results indicate that the NER is a major, early site of the synthesis of 3H-glucosamine labeled membrane glycoproteins, and that these proteins migrate into other ER membranes early after their synthesis.

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
D008565 Membrane Proteins Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors. Cell Membrane Protein,Cell Membrane Proteins,Cell Surface Protein,Cell Surface Proteins,Integral Membrane Proteins,Membrane-Associated Protein,Surface Protein,Surface Proteins,Integral Membrane Protein,Membrane Protein,Membrane-Associated Proteins,Membrane Associated Protein,Membrane Associated Proteins,Membrane Protein, Cell,Membrane Protein, Integral,Membrane Proteins, Integral,Protein, Cell Membrane,Protein, Cell Surface,Protein, Integral Membrane,Protein, Membrane,Protein, Membrane-Associated,Protein, Surface,Proteins, Cell Membrane,Proteins, Cell Surface,Proteins, Integral Membrane,Proteins, Membrane,Proteins, Membrane-Associated,Proteins, Surface,Surface Protein, Cell
D002460 Cell Line Established cell cultures that have the potential to propagate indefinitely. Cell Lines,Line, Cell,Lines, Cell
D002467 Cell Nucleus Within a eukaryotic cell, a membrane-limited body which contains chromosomes and one or more nucleoli (CELL NUCLEOLUS). The nuclear membrane consists of a double unit-type membrane which is perforated by a number of pores; the outermost membrane is continuous with the ENDOPLASMIC RETICULUM. A cell may contain more than one nucleus. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed) Cell Nuclei,Nuclei, Cell,Nucleus, Cell
D002794 Choline A basic constituent of lecithin that is found in many plants and animal organs. It is important as a precursor of acetylcholine, as a methyl donor in various metabolic processes, and in lipid metabolism. Bursine,Fagine,Vidine,2-Hydroxy-N,N,N-trimethylethanaminium,Choline Bitartrate,Choline Chloride,Choline Citrate,Choline Hydroxide,Choline O-Sulfate,Bitartrate, Choline,Chloride, Choline,Choline O Sulfate,Citrate, Choline,Hydroxide, Choline,O-Sulfate, Choline
D003600 Cytosol Intracellular fluid from the cytoplasm after removal of ORGANELLES and other insoluble cytoplasmic components. Cytosols
D004721 Endoplasmic Reticulum A system of cisternae in the CYTOPLASM of many cells. In places the endoplasmic reticulum is continuous with the plasma membrane (CELL MEMBRANE) or outer membrane of the nuclear envelope. If the outer surfaces of the endoplasmic reticulum membranes are coated with ribosomes, the endoplasmic reticulum is said to be rough-surfaced (ENDOPLASMIC RETICULUM, ROUGH); otherwise it is said to be smooth-surfaced (ENDOPLASMIC RETICULUM, SMOOTH). (King & Stansfield, A Dictionary of Genetics, 4th ed) Ergastoplasm,Reticulum, Endoplasmic
D005643 Fucose A six-member ring deoxysugar with the chemical formula C6H12O5. It lacks a hydroxyl group on the carbon at position 6 of the molecule. Deoxygalactose,alpha-Fucose,alpha Fucose
D005944 Glucosamine 2-Amino-2-Deoxyglucose,Dona,Dona S,Glucosamine Sulfate,Hespercorbin,Xicil,2 Amino 2 Deoxyglucose,Sulfate, Glucosamine
D006023 Glycoproteins Conjugated protein-carbohydrate compounds including MUCINS; mucoid, and AMYLOID glycoproteins. C-Glycosylated Proteins,Glycosylated Protein,Glycosylated Proteins,N-Glycosylated Proteins,O-Glycosylated Proteins,Glycoprotein,Neoglycoproteins,Protein, Glycosylated,Proteins, C-Glycosylated,Proteins, Glycosylated,Proteins, N-Glycosylated,Proteins, O-Glycosylated
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