Biomaterial Database

Study of intracellular localization and traffic of newly synthesized ceruloplasmin receptor in cultured human fibroblasts. 1998

L K Sasina, and L V Puchkova, and V S Gaitskhoki

Research Institute for Experimental Medicine, Russian Academy of Medical Sciences, St. Petersburg, 197376, Russia. ludmila@usr8.iem. ras.spb.ru

Ceruloplasmin (Cp) receptor in cells of non-hepatocyte lineage (human HT-1080 fibroblasts) is synthesized by membrane-bound polyribosomes and then becomes a resident of the plasma membrane. The intracellular traffic of [14C]Cp receptor was followed in pulse-chase experiments using specific antibodies. It was shown that pulse-labeled Cp receptor, after reaching the place of its residence in the plasma membrane, is retained there for 90 min and then appears in the cytosol. Immunoactive 20-kD fragments of Cp receptor were found in the culture medium 1.5 h later. The intracellular traffic of 125I-labeled Cp bound to the fibroblast cell surface was traced in parallel chase experiments. It was shown that the internalized Cp receptor was recovered from the floating fraction of the cytosol. Comparison of the dynamics of the retention of internalized [14C]Cp receptor and 125I-labeled Cp in the subcellular compartments demonstrated that the traffic of both proteins within the fibroblasts is coordinated in time and proceeds via a common route. The role of Cp receptor in copper uptake by non-hepatocyte cells is discussed.

UI	MeSH Term	Description	Entries
D007457	Iodine Radioisotopes	Unstable isotopes of iodine that decay or disintegrate emitting radiation. I atoms with atomic weights 117-139, except I 127, are radioactive iodine isotopes.	Radioisotopes, Iodine
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D011971	Receptors, Immunologic	Cell surface molecules on cells of the immune system that specifically bind surface molecules or messenger molecules and trigger changes in the behavior of cells. Although these receptors were first identified in the immune system, many have important functions elsewhere.	Immunologic Receptors,Immunologic Receptor,Immunological Receptors,Receptor, Immunologic,Receptors, Immunological
D002250	Carbon Radioisotopes	Unstable isotopes of carbon that decay or disintegrate emitting radiation. C atoms with atomic weights 10, 11, and 14-16 are radioactive carbon isotopes.	Radioisotopes, Carbon
D002460	Cell Line	Established cell cultures that have the potential to propagate indefinitely.	Cell Lines,Line, Cell,Lines, Cell
D002462	Cell Membrane	The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.	Plasma Membrane,Cytoplasmic Membrane,Cell Membranes,Cytoplasmic Membranes,Membrane, Cell,Membrane, Cytoplasmic,Membrane, Plasma,Membranes, Cell,Membranes, Cytoplasmic,Membranes, Plasma,Plasma Membranes
D002570	Ceruloplasmin	A multi-copper blood FERROXIDASE involved in iron and copper homeostasis and inflammation.	Caeruloplasmin,Ferroxidase,Ceruloplasmin Ferroxidase,Ceruloplasmin Oxidase,Ferroxidase I,alpha(2)-Ceruloplasmin,Ferroxidase, Ceruloplasmin,Oxidase, Ceruloplasmin
D003300	Copper	A heavy metal trace element with the atomic symbol Cu, atomic number 29, and atomic weight 63.55.	Copper-63,Copper 63
D003600	Cytosol	Intracellular fluid from the cytoplasm after removal of ORGANELLES and other insoluble cytoplasmic components.	Cytosols
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man