Activation of exocytosis by the heterotrimeric G protein Gi3.
Secretagogues of rat peritoneal mast cells, such as mastoparan and compound 48/80, induce mast cell exocytosis by activating directly the guanosine triphosphate-binding proteins that are required for exocytosis. The introduction of a synthetic peptide that corresponds to the carboxyl-terminal end sequence of G alpha i3 into the cells specifically blocked this secretion. Similar results were obtained when antibodies to this peptide were introduced. The G alpha i3 was located in both the Golgi and the plasma membrane, but only the latter source of G alpha i3 appeared to be essential for secretion. These results indicate that G alpha i3 functions to control regulated exocytosis in mast cells.
Aridor
M
M
Weizmann Institute of Science, Department of Chemical Immunology, Rehovot, Israel.
Rajmilevich
G
G
Beaven
M A
MA
Sagi-Eisenberg
R
R
D000595:Amino Acid Sequence; D000818:Animals; D005089:Exocytosis / Q000187:drug effects / Q000502:physiology*; D019204:GTP-Binding Proteins / Q000032:analysis / Q000187:drug effects / Q000502:physiology*; D006636:Histamine Release / Q000187:drug effects; D066298:In Vitro Techniques; D008407:Mast Cells / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000494:pharmacology; D051381:Rats; D013347:Subcellular Fractions / Q000737:chemistry; D010566:Virulence Factors, Bordetella / Q000494:pharmacology
D010446:Peptide Fragments; D010566:Virulence Factors, Bordetella; D019204:GTP-Binding Proteins