GSBS Student Publications

Title

Reconstitution into proteoliposomes and partial purification of the Golgi apparatus membrane UDP-galactose, UDP-xylose, and UDP-glucuronic acid transport activities

UMMS Affiliation

Graduate School of Biomedical Sciences; Department of Biochemistry and Molecular Biology

Date

1-5-1992

Document Type

Article

Medical Subject Headings

Animals; Biological Transport; Golgi Apparatus; Lipid Metabolism; Male; Proteolipids; Rats; Rats, Inbred Strains; Temperature; Uridine Diphosphate Galactose; Uridine Diphosphate Glucuronic Acid; Uridine Diphosphate Xylose

Disciplines

Life Sciences | Medicine and Health Sciences

Abstract

Previous studies in vitro on proteoglycan biosynthesis from our laboratory have shown that nucleotide sugar precursors of all the sugars of the linkage oligosaccharides (xylose, galactose, and glucuronic acid) and of the glycosaminoglycans (N-acetylglucosamine, N-galactosamine, and glucuronic acid) are transported by specific carriers into the lumen of Golgi vesicles. More recently, we also reported the reconstitution in phosphatidylcholine liposomes of detergent-solubilized Golgi membrane proteins containing transport activities of CMP-sialic acid and adenosine-3'-phosphate-5'-phosphosulfate. We have now completed the successful reconstitution into liposomes of the Golgi membrane transport activities of UDP-galactose, UDP-xylose, and UDP-glucuronic acid. Transport of these nucleotide sugars into Golgi protein proteoliposomes occurred with the same affinity, temperature dependence, and sensitivity to inhibitors as observed with intact Golgi vesicles. Preloading of proteoliposomes with UMP, the putative antiporter for Golgi vesicle transport of these nucleotide sugars, stimulated transport of the nucleotide sugars by 2-3-fold. Transport of UDP-xylose into Golgi protein proteoliposomes was dependent on the presence of endogenous Golgi membrane lipids while that of UDP-galactose and UDP-glucuronic acid was not. This suggests a possible stabilizing or regulatory role for Golgi lipids on the UDP-xylose translocator. Finally, we have also shown that detergent-solubilized Golgi membrane translocator proteins can be partially purified by an ion-exchange chromatographic step before successful reconstitution into liposomes, demonstrating that this reconstitution approach can be used for the biochemical purification of these transporters.

Rights and Permissions

Citation: J Biol Chem. 1992 Jan 5;267(1):103-7.

Related Resources

Link to article in PubMed

Journal Title

The Journal of biological chemistry

PubMed ID

1730575