Inhibition of basic secretagogue-induced signaling in mast cells by cell permeable G alpha i-derived peptides

Int Arch Allergy Immunol. 2008;145(2):131-40. doi: 10.1159/000108138. Epub 2007 Sep 10.


Background: Basic secretagogues of connective tissue mast cells act as receptor mimetic agents that trigger mast cells by activating G proteins. This leads to simultaneous propagation of two signaling pathways: one that culminates in exocytosis, while the other involves protein tyrosine phosphorylation and leads to release of arachidonic acid metabolites. We have previously shown that introduction of a peptide that comprises the C-terminal end of G alpha i3 into permeabilized mast cells inhibits basic secretagogue-induced exocytosis [Aridor et al., Science 1993;262:1569-1572]. We investigated whether cell-permeable peptides, composed of the C-terminus of G alpha i3 fused with importation sequences, affect mast cell function.

Methods: Following preincubation with the fused peptides, rat peritoneal mast cells were activated by compound 48/80 and analyzed for histamine and prostaglandin D2 release and protein tyrosine phosphorylations.

Results: We demonstrate that out of three importation sequences tested only G alpha i3 peptide fused with the Kaposi fibroblast growth factor importation sequence (ALL1) inhibited release of histamine. ALL1 as well as a cell-permeable peptide that corresponds to G alpha i2 also blocked compound 48/80-stimulated protein tyrosine phosphorylation, though the latter did not block histamine release. ALL1 effect was G protein-specific, as it was incapable of blocking protein tyrosine phosphorylation stimulated by pervanadate.

Conclusion: ALL1, a transducible G alpha i3-corresponding peptide, blocks the two signaling pathways in mast cells: histamine release and protein tyrosine phosphorylation. Cell permeable peptides that block these two signaling cascades may constitute a novel approach for preventing the onset of the allergic reaction.

Publication types

  • Comparative Study

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Cell Membrane Permeability
  • Drug Evaluation, Preclinical
  • GTP-Binding Protein alpha Subunit, Gi2 / pharmacology
  • GTP-Binding Protein alpha Subunits, Gi-Go / pharmacology*
  • Histamine Release / drug effects
  • Inflammation Mediators / physiology*
  • Integrin beta3 / chemistry
  • Mast Cells / drug effects*
  • Mast Cells / metabolism
  • Molecular Sequence Data
  • Peptide Fragments / chemical synthesis
  • Peptide Fragments / pharmacology
  • Peptides / chemical synthesis
  • Peptides / pharmacology*
  • Phosphorylation / drug effects
  • Prostaglandin D2 / metabolism
  • Protein Processing, Post-Translational / drug effects
  • Rats
  • Rats, Wistar
  • Signal Transduction / drug effects
  • Transducin / pharmacology
  • p-Methoxy-N-methylphenethylamine / antagonists & inhibitors


  • ALL1 peptide
  • Inflammation Mediators
  • Integrin beta3
  • Peptide Fragments
  • Peptides
  • p-Methoxy-N-methylphenethylamine
  • GTP-Binding Protein alpha Subunit, Gi2
  • GTP-Binding Protein alpha Subunits, Gi-Go
  • Gnai2 protein, rat
  • Gnai3 protein, rat
  • Transducin
  • Prostaglandin D2