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Multiple trimeric G-proteins on the trans-Golgi network exert stimulatory and inhibitory effects on secretory vesicle formation.

1992; Springer Nature; Volume: 11; Issue: 13 Linguagem: Inglês

10.1002/j.1460-2075.1992.tb05585.x

1460-2075

Anja Leyte, Francis A. Barr, Ralph H. Kehlenbach, Wieland Β. Huttner,

Supramolecular Self-Assembly in Materials

Research Article1 December 1992free access Multiple trimeric G-proteins on the trans-Golgi network exert stimulatory and inhibitory effects on secretory vesicle formation. A. Leyte A. Leyte Institute for Neurobiology, University of Heidelberg, Germany. Search for more papers by this author F.A. Barr F.A. Barr Institute for Neurobiology, University of Heidelberg, Germany. Search for more papers by this author R.H. Kehlenbach R.H. Kehlenbach Institute for Neurobiology, University of Heidelberg, Germany. Search for more papers by this author W.B. Huttner W.B. Huttner Institute for Neurobiology, University of Heidelberg, Germany. Search for more papers by this author A. Leyte A. Leyte Institute for Neurobiology, University of Heidelberg, Germany. Search for more papers by this author F.A. Barr F.A. Barr Institute for Neurobiology, University of Heidelberg, Germany. Search for more papers by this author R.H. Kehlenbach R.H. Kehlenbach Institute for Neurobiology, University of Heidelberg, Germany. Search for more papers by this author W.B. Huttner W.B. Huttner Institute for Neurobiology, University of Heidelberg, Germany. Search for more papers by this author Author Information A. Leyte1, F.A. Barr1, R.H. Kehlenbach1 and W.B. Huttner1 1Institute for Neurobiology, University of Heidelberg, Germany. The EMBO Journal (1992)11:4795-4804https://doi.org/10.1002/j.1460-2075.1992.tb05585.x PDFDownload PDF of article text and main figures. ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinked InMendeleyWechatReddit Figures & Info The role of heterotrimeric G-proteins on the formation of constitutive secretory vesicles (CSVs) and immature secretory granules (ISGs) from the trans-Golgi network (TGN) of PC12 cells was investigated. Using immunofluorescence and subcellular fractionation in conjunction with immunoblotting or ADP-ribosylation by either pertussis toxin or cholera toxin, TGN membranes were found to contain not only several alpha i/alpha o G-protein subunits including apparently alpha i3, but also alpha s. Pertussis toxin treatment of cells, which resulted in the stoichiometric ADP-ribosylation of alpha i/alpha o, a modification known to prevent their coupling to receptors, led to the stimulation of cell-free CSV and ISG formation, suggesting the presence of a guanine nucleotide exchange factor for alpha i/alpha o on the TGN. Mastoparan-7, a peptide known to mimic an activated receptor and to stimulate nucleotide exchange on alpha i/alpha o, inhibited cell-free vesicle formation, an effect abolished by pertussis toxin. In contrast, activation of alpha s by cholera toxin treatment of cells resulted in a stimulation of cell-free CSV and ISG formation. This stimulation could be reversed when the alpha subunits not activated by cholera toxin, i.e. alpha i/alpha o, were activated by GTP gamma S and [AIF4]-. Our results show that both inhibitory and stimulatory trimeric G-proteins on the TGN participate in the regulation of secretory vesicle formation. Previous ArticleNext Article Volume 11Issue 131 December 1992In this issue RelatedDetailsLoading ...