Ectoglycosyltransferase Activities During Neuronal Differentiation in Cell Cultures
It is generally admitted that glycosyltransferases and the synthesis machinery of glycoconjugates are localized in the intracellular membrane structures such as the endoplasmic reticulum (Cook et al. 1965), Golgi apparatus (Schachter et al. 1970; Fleischer et al. 1969) and mitochondrial membranes (Bosman 1971; Broquet et al. 1975). Recently several reports concluded that glycosyltransferases also exist at the cell curface with their active sites exposed to the extracellular space (see for review Shur and Roth 1975; Cacan et al. 1976). The methods applied for detection of these ectoenzymes were direct enzymatic assays of intact cells or membranes as well as immunocytochemistry using antisera against glycosyltransferases and autoradiography (for review see Shur and Roth 1975; Shur 1982). Most frequently the addition of a radiolabeled sugar from a sugar nucleotide to the plasma membrane of intact cells was used to test ectoglycosyltransferase activities. According to the results obtained, the presence of ectoglycosyltransferase activities was reported at the cell surface of lymphocytes (Cacan et al. 1976; Hoflack et al. 1979), leukemic cells (Bernacki and Porter 1978), cultured nerve cells from chick embryo retinas (Roth et al. 1971), embryonic liver (Arnold et al. 1973), sperm (Shur and Bennet 1979), teratocarcinoma cells (Shur and Roth 1975; Shur 1982) and migrating mesenchymal cells (Hakomori 1981; Johnson 1977).
KeywordsSugar Nucleotide Neuraminic Acid Glycosyltransferase Activity Sialyltransferase Activity Ectoenzyme Activity
Unable to display preview. Download preview PDF.
- Chen KY, Rinehart Jr CA (1982) Identification of exposed surface glycoproteins in undifferenti-ated and differentiated mouse N-18 neuroblastoma cells.Biochim Biophys Acta 685: 61–70Google Scholar
- DeFeudis FV, Ossola L, Sarlieve LL, Schmitt G, Rebel G, Varga V, Mandel P (1981) GABA and muscimol binding processes in CNS tissue culture preparations. In: Amino acid neurotransmitters. DeFeudis FV, Mandel P (eds) Raven Press NY, pp 405–410Google Scholar
- Hakomori SI (1973) Glycolipids-their chemical pattern, synthesis and degradation in normal and tumor cells. In: Tumor lipids. Biochemistry and metabolism, Wood R (ed) American Oil Che-mist’s Society Press, Champaign ( Illinois, USA ), pp 269–284Google Scholar
- Horowitz MI (ed) The glycoconjugates, vol. Ill (1982) Academic Press New York, pp 369Google Scholar
- Ledeen RW, Yu RK (1976) Gangliosides of nervous system. In: Glycolipid methodology, Witting LA (ed) American Oil Chemist’s Society Press, Champaign ( Illinois, USA ), pp 187–214Google Scholar
- Mahler HR (1979) Glycoproteins of the synapse. In: Complex carbohydrates of nervous tissue, Margolis RU, Margolis RK (eds), Plenum Press New York, pp 165–184Google Scholar
- Maitre M, Mandel P (1984) Gamma-hydroxybutyrate, a putative neurotransmitter in the central nervous system.CR Acad Sci Paris 298: 341–345Google Scholar
- Robert J, Rebel G, Mandel P (1977) Glycosphingolipids from cultured astroblasts.J Lipid Res 18: 517–522Google Scholar
- Shur BD (1982) Cell surface glycosyltransferase activities during fertilization and early embryo- genesis. In: The glycoconjugates, vol. III, Horowitz MI (ed) Academic Press Inc., pp 146–185Google Scholar
- Svennerholm L (1980) Gangliosides and synaptic transmission. In: Structure and function of gangliosides. Svennerholm L, Mandel P, Dreyfus H, Urban PF (eds) Plenum Press, pp 533–544Google Scholar
- Yamakawa T, Nagai Y (1978) Glycolipids at the cell surface and their biological functions.TIBS 3: 128–131Google Scholar