Retrograde Transport from the Golgi Complex to the ER of Both Shiga Toxin and the Nontoxic Shiga B-Fragment Is Regulated by Butyric Acid and cAMP

• Published in: The Journal of cell biology 1994-07, Vol.126 (1), p.53-64
• Main Authors: Sandvig, Kirsten, Ryd, Marie, Garred, Øystein, Schweda, Elke, Holm, Pernille Kaae, van Deurs, Bo
• Format: Article
• Language: English
• Subjects: Bacterial Toxins - metabolism; Bacterial Toxins - pharmacology; Biological and medical sciences; Biological Transport - drug effects; Butyrates - pharmacology; Butyric Acid; Carbohydrate Sequence; Cell Compartmentation; Cell lines; Cell physiology; Cells; Cellular biology; Cholera; Cholera Toxin - metabolism; Cholera Toxin - pharmacology; Cyclic AMP - pharmacology; Dose-Response Relationship, Drug; Drug Interactions; Endoplasmic Reticulum - metabolism; Endoplasmic Reticulum - ultrastructure; Epithelial cells; Fatty acids; Fundamental and applied biological sciences. Psychology; Glycolipids; Glycolipids - metabolism; Golgi apparatus; Golgi Apparatus - metabolism; Golgi Apparatus - ultrastructure; HeLa cells; Horseradish Peroxidase - metabolism; Humans; Membrane and intracellular transports; Molecular and cellular biology; Molecular Sequence Data; Organelles - metabolism; Organelles - ultrastructure; Peptide Fragments - metabolism; Proteins; Ricin - metabolism; Ricin - pharmacology; Shiga Toxins; Toxins; Trihexosylceramides - isolation & purification; Tumor Cells, Cultured
• ISSN: 0021-9525; 1540-8140
• DOI: 10.1083/jcb.126.1.53

Endocytosed Shiga toxin is transported from the Golgi complex to the endoplasmic reticulum in butyric acid-treated A431 cells. We here examine the extent of this retrograde transport and its regulation. The short B fragment of Shiga toxin is sufficient for transport to the ER. The B fragment of cholera toxin, which also binds to glycolipids, is transported to all the Golgi cisterns, but cannot be localized in the ER even after butyric acid treatment. Under all conditions the toxic protein ricin was found predominantly in the trans-Golgi network. There is no transport of endocytosed fluid to the Golgi apparatus or to the ER even after butyric acid treatment and in the presence of Shiga toxin, indicating that transport to the ER, through the trans-Golgi network and the cisterns of the Golgi apparatus, involves several sorting stations. Since Shiga toxin receptors (Gb3) in butyric acid-treated A431 cells seem to have a ceramide moiety with longer fatty acids than in untreated cells, the possibility exists that fatty acid composition of the receptor is important for sorting to the ER. Both retrograde transport and intoxication with Shiga toxin can also be induced by cAMP, supporting the idea that retrograde transport from the Golgi to the ER is required for intoxication. The data suggest that transport to the ER in cells in situ may depend on fatty acid composition and is regulated by physiological signals.