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Biosynthesis and transport of plasma membrane glycoproteins in the rat intestinal epithelial cell : studies with sucrase-isomaltase

Hauri, H. P.. (1983) Biosynthesis and transport of plasma membrane glycoproteins in the rat intestinal epithelial cell : studies with sucrase-isomaltase. In: Brush border membranes. London, pp. 132-163.

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Official URL: http://edoc.unibas.ch/dok/A5257728

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Abstract

Sucrase-isomaltase (SI), an integral heterodimeric glycoprotein of the intestinal microvillus membrane, is synthesized as a single enzymically active precursor protein (pro-SI) of high relative molecular mass. After glycosylation in the Golgi complex pro-SI is transferred to the microvillus membrane where it is cleaved into the two subunits by pancreatic elastase. Pro-SI was purified by monoclonal antibody-affinity chromatography from microvillus membranes of fetal intestinal transplants in which SI is found exclusively in the non-cleaved precursor form. The N-terminal amino acid sequence of pro-SI was identical to that of the isomaltase subunit of SI which anchors the mature enzyme complex to the lipid bilayer, but it differed from the N-terminal sequence of the sucrase subunit of SI. This structural comparison indirectly gave insight into the mechanisms of membrane insertion and assembly of pro-SI during its biosynthesis. Subcellular fractionation studies indicate transient structural association of newly synthesized pro-SI with the basolateral membrane on its transfer from the Golgi complex to the microvillus membrane, suggesting that part of the basolateral membrane or its associated structures might be involved in the sorting-out processes of microvillar membrane proteins. This concept may have general relevance for the mechanisms of membrane insertion, intracellular transport and sorting of other microvillar membrane glycoproteins in the intestinal epithelial cell.
Faculties and Departments:05 Faculty of Science > Departement Biozentrum > Former Organization Units Biozentrum > Pharmacology/Neurobiology (Hauri)
UniBasel Contributors:Hauri, Hans-Peter
Item Type:Conference or Workshop Item
Conference or workshop item Subtype:Conference Paper
Publisher:Pitman
ISBN:0-272-79659-X
Series Name:Ciba Foundation symposium
Issue Number:95
Note:Publication type according to Uni Basel Research Database: Conference paper
Last Modified:22 Mar 2012 14:22
Deposited On:22 Mar 2012 13:31

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