Regulation of exocytosis by the small GTP-binding protein Rho in rat basophilic leukemia (RBL-2H3) cells.

Abstract

1. We investigated the effect of Clostridium botulinum C3 ADP-ribosyltransferase upon beta-hexosaminidase release induced by various stimuli from streptolysin-O (0.5-1 U/ml)-permeabilized rat basophilic leukemia (RBL-2H3) cells. 2. The C3 transferase inhibited beta-hexosaminidase release induced by Ca2+ or by guanosine-5'-(3-thiotriphosphate) (GTP gamma S) plus Ca2+. 3. The C3 transferase also inhibited beta-hexosaminidase release induced by stimulating high affinity IgE and m3 muscarinic acetylcholine receptors. 4. The substrate for the C3 transferase was present in cytosol of RBL-2H3 cells, indicating the presence of rho p21. About 60% of the total cellular substrate protein remained within the cells permeabilized by 1 U/ml of streptolysin-O. 5. The protein rho p21 appears to be regulated by several pathways and it may function as an integration point for exocytosis.

• Authors: S G Yonei, K Oishi, M K Uchida
• Journal: General pharmacology (Gen Pharmacol) Vol. 26 Issue 7 Pg. 1583-9 (Nov 1995) ISSN: 0306-3623 [Print] England
• PMID: 8690250 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• ADP Ribose Transferases
• exoenzyme C3, Clostridium botulinum
• beta-N-Acetylhexosaminidases
• Botulinum Toxins
• GTP-Binding Proteins
• rho GTP-Binding Proteins

Topics

• ADP Ribose Transferases (metabolism)
• Animals
• Botulinum Toxins
• Cell Membrane Permeability
• Clostridium botulinum (enzymology)
• Exocytosis (drug effects)
• GTP-Binding Proteins (analysis, metabolism)
• Leukemia, Basophilic, Acute
• Rats
• Tumor Cells, Cultured
• beta-N-Acetylhexosaminidases (metabolism)
• rho GTP-Binding Proteins