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Inhibition of oligosaccharide processing and membrane morphogenesis in retinal rod photoreceptor cells.
Fliesler SJ, Rayborn ME, Hollyfield JG.
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Castanospermine (Cas), an inhibitor of alpha-glucosidase I, blocks "trimming" of the N-linked oligosaccharide Glc3Man9GlcNAc2, thus preventing normal glycoprotein maturation. With use of a dual-label protocol, Xenopus retinas incubated in the presence of Cas exhibited at least a 2.3-fold increase in the incorporation of [3H]mannose into total retina Cl3CCOOH-precipitable material, whereas incorporation of [14C]leucine was not significantly affected, relative to controls. Analysis of NaDodSO4/PAGE fluorograms of solubilized retinas and rod outer segment (ROS) membranes indicated a relatively selective effect of Cas on opsin (the rod visual pigment apoglycoprotein). The apparent molecular mass of opsin was increased by approximately 2500 in the presence of Cas; the incorporation of [3H]mannose into opsin was enhanced about 2.3-fold without a significant effect on [14C]leucine incorporation, relative to controls. Electron microscopic autoradiography of retinas incubated for 4 hr with [3H]mannose showed that the number of newly formed ROS discs in Cas-treated retinas was not significantly different from controls, but the silver grain density over those discs was about 2.6-fold greater than in controls. The morphology of the newly formed discs was comparable under both conditions. Thus, opsin bearing abnormally large oligosaccharides can be accommodated in the process of disc morphogenesis. These results suggest that the structural requirements for opsin's oligosaccharides, with regard to their potential role as determinants of disc morphogenesis, are not stringent. Furthermore, post-translational processing of N-linked oligosaccharides is not essential for the normal intracellular routing and cell surface expression of membrane glycoproteins.
Berger,
Structure, biosynthesis and functions of glycoprotein glycans.
1982, Pubmed
Berger,
Structure, biosynthesis and functions of glycoprotein glycans.
1982,
Pubmed Bok,
Retinal photoreceptor-pigment epithelium interactions. Friedenwald lecture.
1985,
Pubmed Burke,
Inhibition of N-linked oligosaccharide trimming does not interfere with surface expression of certain integral membrane proteins.
1984,
Pubmed Daemen,
Vertebrate rod outer segment membranes.
1973,
Pubmed Elbein,
Inhibitors of the biosynthesis and processing of N-linked oligosaccharides.
1984,
Pubmed Fliesler,
Membrane morphogenesis in retinal rod outer segments: inhibition by tunicamycin.
1985,
Pubmed
,
Xenbase Fliesler,
Chemistry and metabolism of lipids in the vertebrate retina.
1983,
Pubmed Fliesler,
Tunicamycin blocks the incorporation of opsin into retinal rod outer segment membranes.
1985,
Pubmed Fliesler,
Photoreceptor-specific degeneration caused by tunicamycin.
,
Pubmed Fukuda,
Rhodopsin carbohydrate. Structure of small oligosaccharides attached at two sites near the NH2 terminus.
1979,
Pubmed Hargrave,
The amino-terminal tryptic peptide of bovine rhodopsin. A glycopeptide containing two sites of oligosaccharide attachment.
1977,
Pubmed Hargrave,
Rhodopsin's protein and carbohydrate structure: selected aspects.
1984,
Pubmed Hollyfield,
The emergence, localization and maturation of neurotransmitter systems during development of the retina in Xenopus laevis. I. Gamma aminobutyric acid.
1979,
Pubmed
,
Xenbase Hollyfield,
Membrane addition to rod photoreceptor outer segments: light stimulates membrane assembly in the absence of increased membrane biosynthesis.
1982,
Pubmed
,
Xenbase Hori,
Inhibition of processing of plant N-linked oligosaccharides by castanospermine.
1984,
Pubmed Hubbard,
Synthesis and processing of asparagine-linked oligosaccharides.
1981,
Pubmed Kornfeld,
Assembly of asparagine-linked oligosaccharides.
1985,
Pubmed Liang,
Structure of the carbohydrate moieties of bovine rhodopsin.
1979,
Pubmed O'Brien,
Rhodopsin as a glycoprotein: a possible role for the oligosaccharide in phagocytosis.
1976,
Pubmed O'Brien,
Differential effects of puromycin on the incorporation of precursors of rhodopsin in bovine retina.
1977,
Pubmed O'Brien,
Characteristics of galactosyl and fucosyl transfer to bovine rhodopsin.
1978,
Pubmed Olden,
Carbohydrate moieties of glycoproteins. A re-evaluation of their function.
1982,
Pubmed Pan,
Castanospermine inhibits the processing of the oligosaccharide portion of the influenza viral hemagglutinin.
1983,
Pubmed Plantner,
Effect of tunicamycin on the glycosylation of rhodopsin.
1980,
Pubmed Plantner,
Carbohydrate composition of bovine rhodopsin.
1976,
Pubmed Saul,
Castanospermine inhibits alpha-glucosidase activities and alters glycogen distribution in animals.
1985,
Pubmed Schwarz,
The lipid pathway of protein glycosylation and its inhibitors: the biological significance of protein-bound carbohydrates.
1982,
Pubmed Steinberg,
Disc morphogenesis in vertebrate photoreceptors.
1980,
Pubmed Young,
Visual cells and the concept of renewal.
1976,
Pubmed
