Biomaterial Database

Involvement of spectrin in cell-surface receptor capping in lymphocytes. 1983

W J Nelson, and C A Colaço, and E Lazarides

Human and mouse lymphocytes of T- and B-cell lineages express a protein (Mr, 240,000) that crossreacts with antibodies raised against chicken erythrocyte alpha-spectrin as judged by immunofluorescence, immunoprecipitation, and immunoautoradiography; by the same criteria, antibodies raised against chicken erythrocyte beta-spectrin do not react with any lymphocyte polypeptide. In all T and B cells analyzed, before surface-directed ligand challenge with concanavalin A and surface immunoglobulins the polypeptide antigenically related to erythrocyte alpha-spectrin is distributed diffusely at the plasma membrane. Upon challenge, the redistribution of this polypeptide is concurrent with that of the cell-surface receptors initially in patches and then in a cap. Immunoprecipitation of NaDodSO4-solubilized lymphocytes with erythrocyte alpha-spectrin antiserum shows that in all cases a polypeptide with the same apparent molecular weight as erythrocyte alpha-spectrin is precipitated. Variable amounts of another polypeptide (Mr, 235,000) are also coimmunoprecipitated. Immunoprecipitations and subsequent immunoautoradiography show that the lymphocyte polypeptide doublet has a composition similar to that of (brain) fodrin, a polypeptide doublet that previously has been found mainly in the cells of nervous tissue.

UI	MeSH Term	Description	Entries
D007152	Immunologic Capping	An energy dependent process following the crosslinking of B CELL ANTIGEN RECEPTORS by multivalent ligands (bivalent anti-antibodies, LECTINS or ANTIGENS), on the B-cell surface. The crosslinked ligand-antigen receptor complexes collect in patches which flow to and aggregate at one pole of the cell to form a large mass - the cap. The caps may then be endocytosed or shed into the environment.	Capping, Immunologic,Immunological Capping,Capping, Immunological
D008214	Lymphocytes	White blood cells formed in the body's lymphoid tissue. The nucleus is round or ovoid with coarse, irregularly clumped chromatin while the cytoplasm is typically pale blue with azurophilic (if any) granules. Most lymphocytes can be classified as either T or B (with subpopulations of each), or NATURAL KILLER CELLS.	Lymphoid Cells,Cell, Lymphoid,Cells, Lymphoid,Lymphocyte,Lymphoid Cell
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
D008970	Molecular Weight	The sum of the weight of all the atoms in a molecule.	Molecular Weights,Weight, Molecular,Weights, Molecular
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
D003599	Cytoskeleton	The network of filaments, tubules, and interconnecting filamentous bridges which give shape, structure, and organization to the cytoplasm.	Cytoplasmic Filaments,Cytoskeletal Filaments,Microtrabecular Lattice,Cytoplasmic Filament,Cytoskeletal Filament,Cytoskeletons,Filament, Cytoplasmic,Filament, Cytoskeletal,Filaments, Cytoplasmic,Filaments, Cytoskeletal,Lattice, Microtrabecular,Lattices, Microtrabecular,Microtrabecular Lattices
D013049	Spectrin	A high molecular weight (220-250 kDa) water-soluble protein which can be extracted from erythrocyte ghosts in low ionic strength buffers. The protein contains no lipids or carbohydrates, is the predominant species of peripheral erythrocyte membrane proteins, and exists as a fibrous coating on the inner, cytoplasmic surface of the membrane.	alpha-Spectrin,beta-Spectrin,alpha Spectrin,beta Spectrin
D046911	Macromolecular Substances	Compounds and molecular complexes that consist of very large numbers of atoms and are generally over 500 kDa in size. In biological systems macromolecular substances usually can be visualized using ELECTRON MICROSCOPY and are distinguished from ORGANELLES by the lack of a membrane structure.	Macromolecular Complexes,Macromolecular Compounds,Macromolecular Compounds and Complexes,Complexes, Macromolecular,Compounds, Macromolecular,Substances, Macromolecular