Take our Survey

Reference: Cabib E, et al. (1983) Vectorial synthesis of a polysaccharide by isolated plasma membranes. Proc Natl Acad Sci U S A 80(11):3318-21

Reference Help

Abstract


To ascertain the directionality of chitin synthesis by yeast plasma membranes, the external surface of Saccharomyces cerevisiae protoplasts was labeled with ferritin--concanavalin A. After protoplast lysis, plasma membranes were isolated and treated with trypsin to activate chitin synthase (UDP-2-acetamido-2-deoxy-D-glucose:chitin 4-beta-acetamidodeoxy-D-glucosyl-transferase, EC 2.4.1.16). The membranes were then enrobed in agar and allowed to synthesize chitin from UDP-N-acetylglucosamine. After fixation and embedding in Epon, thin sections were stained for chitin with wheat germ agglutinin--colloidal gold complexes. The chitin marker was found near the ferritin-labeled external face of the membrane--i.e., the polysaccharide was located on the outside of the membrane, as it is in the intact cell. Chitin synthase activity was not detected in intact protoplasts before or after treatment with trypsin. The enzyme became available to trypsin activation after lysis of the protoplasts. Together with similar, previously reported experiments on the inactivation of chitin synthase by glutaraldehyde, these results indicate that the enzyme faces the interior of the cell. We conclude that, both in vivo and in vitro, the synthase receives N-acetylglucosamine residues from UDP-N-acetylglucosamine at the cytoplasmic face of the membrane and transfers them vectorially to a growing chain of chitin that is concomitantly extruded to the outside.

Reference Type
Journal Article
Authors
Cabib E, Bowers B, Roberts RL
Primary Lit For
Additional Lit For
Review For

Interaction Annotations


Increase the total number of rows showing on this page by using the pull-down located below the table, or use the page scroll at the table's top right to browse through the table's pages; use the arrows to the right of a column header to sort by that column; filter the table using the "Filter" box at the top of the table; click on the small "i" buttons located within a cell for an annotation to view further details about experiment type and any other genes involved in the interaction.

Interactor Interactor Type Assay Annotation Action Modification Phenotype Source Reference

Gene Ontology Annotations


Increase the total number of rows showing on this page using the pull-down located below the table, or use the page scroll at the table's top right to browse through the table's pages; use the arrows to the right of a column header to sort by that column; filter the table using the "Filter" box at the top of the table.

Gene Gene Ontology Term Qualifier Aspect Method Evidence Source Assigned On Annotation Extension Reference

Phenotype Annotations


Increase the total number of rows showing on this page using the pull-down located below the table, or use the page scroll at the table's top right to browse through the table's pages; use the arrows to the right of a column header to sort by that column; filter the table using the "Filter" box at the top of the table; click on the small "i" buttons located within a cell for an annotation to view further details.

Gene Phenotype Experiment Type Mutant Information Strain Background Chemical Details Reference

Regulation Annotations


Increase the total number of rows displayed on this page using the pull-down located below the table, or use the page scroll at the table's top right to browse through the table's pages; use the arrows to the right of a column header to sort by that column; to filter the table by a specific experiment type, type a keyword into the Filter box (for example, “microarray”); download this table as a .txt file using the Download button or click Analyze to further view and analyze the list of target genes using GO Term Finder, GO Slim Mapper, SPELL, or YeastMine.

Regulator Target Experiment Assay Construct Conditions Strain Background Reference