English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

It has been proposed that synthesis of beta-1,6-glucan, one of Saccharomyces cerevisiae cell wall components, is initiated by a uridine diphosphate (UDP)-glucose-dependent reaction in the lumen of the endoplasmic reticulum (ER). Because this sugar nucleotide is not synthesized in the lumen of the ER, we have examined whether or not UDP-glucose can be transported across the ER membrane. We have detected transport of this sugar nucleotide into the ER in vivo and into ER-containing microsomes in vitro. Experiments with ER-containing microsomes showed that transport of UDP-glucose was temperature dependent and saturable with an apparent Km of 46 microM and a Vmax of 200 pmol/mg protein/3 min. Transport was substrate specific because UDP-N-acetylglucosamine did not enter these vesicles. Demonstration of UDP-glucose transport into the ER lumen in vivo was accomplished by functional expression of Schizosaccharomyces pombe UDP-glucose:glycoprotein glucosyltransferase (GT) in S. cerevisiae, which is devoid of this activity. Monoglucosylated protein-linked oligosaccharides were detected in alg6 or alg5 mutant cells, which transfer Man9GlcNAc2 to protein; glucosylation was dependent on the inhibition of glucosidase II or the disruption of the gene encoding this enzyme. Although S. cerevisiae lacks GT, it contains Kre5p, a protein with significant homology and the same size and subcellular location as GT. Deletion mutants, kre5Delta, lack cell wall beta-1,6 glucan and grow very slowly. Expression of S. pombe GT in kre5Delta mutants did not complement the slow-growth phenotype, indicating that both proteins have different functions in spite of their similarities.

Uridine Diphosphate–Glucose Transport into the Endoplasmic Reticulum ofSaccharomyces cerevisiae:In Vivo and In Vitro Evidence