VIP activates G(s) and G(i3) in rat alveolar macrophages and G(s) in HEK293 cells transfected with the human VPAC1 receptor

S. M. Shreeve, S. P. Sreedharan, M. P. Hacker, D. E. Gannon, M. J. Morgan

Research output: Contribution to journalArticle

14 Scopus citations

Abstract

We have characterized vasoactive intestinal peptide (VIP) receptor/G-protein coupling in rat alveolar macrophage (AM) membranes and find that pertussis toxin treatment and antisera against G(αi3) and G(αs) reduce high-affinity 125I-VIP binding, indicating that both G(αs) and G(αi3) couple to the VIP-receptor. The predominant VIP-receptor subtype in AM is VPAC1 and we examined the G-protein interactions of the human VPAC1 that had been transfected into HEK293 cells. VPAC1 has a molecular mass of 56 kDa; GTP analogs reduced 125I-VIP binding to this protein demonstrating that high-affinity binding of VIP to the receptor requires coupling to G-protein. Functional VIP/VPAC1/ G-protein complexes were captured by covalent cross-linking and analyzed by Western blotting. The transfected human VPAC1 receptor in HEK293 was found to be coupled to G(αs) but not G(αi) or G(αq). Furthermore, pertussis toxin treatment had no effect on VPAC1/G-protein coupling in these cells. These observations suggest that the G-proteins activated by VPAC1 may be dependent upon species and cell type. (C) 2000 Academic Press.

Original languageEnglish (US)
Pages (from-to)922-928
Number of pages7
JournalBiochemical and Biophysical Research Communications
Volume272
Issue number3
DOIs
StatePublished - Jun 16 2000

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Keywords

  • G(i3)
  • G-protein
  • G-protein, inhibitory
  • Human VPAC
  • Lung
  • Rat alveolar macrophages
  • Receptor signaling
  • Vasoactive intestinal peptide
  • Vasoactive intestinal peptide receptors

ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Molecular Biology
  • Cell Biology

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