Neuronal Process Outgrowth of Human Sensory Neurons on Monolayers of Cells Transfected with cDNAs for Five Human N-CAM Isoforms

• Published in: The Journal of cell biology Vol. 109; no. 2; pp. 789 - 798
• Main Authors: Doherty, Patrick, Barton, C. Howard, Dickson, George, Seaton, Patricia, Rowett, Lewis H., Moore, Stephen E., Gower, Hilary J., Walsh, Frank S.
• Format: Journal Article
• Language: English
• Published: New York, NY Rockefeller University Press 01.08.1989; The Rockefeller University Press
• Subjects: 3T3 cells; Animals; Antibodies; Antigens, Surface - genetics; Antigens, Surface - metabolism; Antigens, Surface - physiology; Biological and medical sciences; Cell adhesion; Cell Adhesion Molecules; Cell cycle, cell proliferation; Cell Differentiation; Cell Line; Cell lines; Cell physiology; Cells, Cultured; Complementary DNA; DNA - genetics; Fibroblasts - cytology; Fibroblasts - metabolism; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation; Humans; Immunohistochemistry; Intermediate Filament Proteins - immunology; Intermediate Filament Proteins - metabolism; L cells; Mice; Molecular and cellular biology; Neurites; Neurofilament proteins; Neurons; Neurons, Afferent - cytology; Neurons, Afferent - metabolism; Protein isoforms; Rats; Species Specificity; Transfection; Human; Cell culture; Rat; Growth; Rodentia; Cell adhesion molecule; 3T3-Cell line; Indirect immunofluorescence; Cell differentiation; Gene expression; Vertebrata; L-»Cell; Immunoprecipitation reaction; Mammalia; Transfection; Complementary DNA; Immunoblotting assay; Sensory neuron; Nucleic acid
• ISSN: 0021-9525; 1540-8140
• DOI: 10.1083/jcb.109.2.789

Full length cDNAs for a variety of human N-CAM isoforms have been transfected into mouse L-cells and/or 3T3 cells. Three independent clones of each cell line that were shown to express human N-CAM were tested for their ability to support the morphological differentiation of sensory neurons. The cell surface expression of N-CAM isoforms, linked to the membrane directly by an integral transmembrane spanning domain or indirectly via covalent attachment to a glycosyl-phosphatidylinositol moiety, were consistently found to be associated with a significant increase in the morphological differentiation of both human and rat dorsal root ganglion neurons. Modification of the extracellular structure of both classes of N-CAM, consequent to the expression of a glycosylated 37-amino acid sequence normally found expressed exclusively in muscle N-CAM isoforms did not obviously affect the ability of transfected cells to support increased neuronal differentiation. 3T3 cells that were transfected with a full length cDNA encoding a secreted N-CAM isoform, and that have previously been shown to secrete N-CAM into the growth media rather than link it to the membrane did not significantly differ from control cells in their ability to support neuronal differentiation. These data provide direct evidence for both transmembrane and lipid-linked N-CAM isoforms being components of the regulatory machinery that determines neuronal morphology and process outgrowth.