G protein activation: a receptor-independent mode of action for cationic amphiphilic neuropeptides and venom peptides.
The neuropeptide substance P, the venom peptide mastoparan and the synthetic polyamine compound 48/80 activate rat peritoneal mast cells, leading to rapid histamine release by exocytosis. Although these effects are inhibited by pertussis toxin and involve a transient increase in IP3, no selective membrane receptors have been identified. However, it has recently been shown that these compounds activate G proteins in vitro. Here Yves Landry and colleagues discuss the proposal that direct activation of G protein is the physiological mechanism of action of substance P on rat peritoneal mast cells, this mechanism being mimicked by mastoparan and 48/80, and possibly by other cationic amphiphilic peptides such as kinins. These compounds might be of help in defining the interaction between membrane receptors and G proteins.
Mousli
M
M
Laboratoire de Neuroimmunopharmacologie, Faculté de Pharmacie, Université Louis Pasteur, Strasbourg I, Illkirch, France.
Bueb
J L
JL
Bronner
C
C
Rouot
B
B
Landry
Y
Y
D000595:Amino Acid Sequence; D000818:Animals; D001711:Biotransformation; D019204:GTP-Binding Proteins / Q000378:metabolism*; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins; D008969:Molecular Sequence Data; D009479:Neuropeptides / Q000737:chemistry / Q000494:pharmacology*; D010455:Peptides; D014862:Wasp Venoms / Q000737:chemistry / Q000494:pharmacology*
D036341:Intercellular Signaling Peptides and Proteins; D009479:Neuropeptides; D010455:Peptides; D014862:Wasp Venoms; C037500:mastoparan; D019204:GTP-Binding Proteins