Immunoprecipitation of A1 adenosine receptor-GTP-binding protein complexes in ciliary epithelial cells

M. B. Wax, R. V. Patil

Research output: Contribution to journalArticle

18 Scopus citations

Abstract

Purpose. To examine the interaction of α subunits of guanine nucleotide binding proteins with A1 adenosine receptors from the SV40-transformed bovine-derived pigmented (PE) and human-derived nonpigmented (NPE) ciliary epithelial cell lines using an immunoprecipitation approach and [3H]DPCPX, a selective radioligand to adenosine receptor. Methods. Solubilized preparations of adenosine receptors from PE and NPE cell lines were immunoprecipitated with G protein specific antisera 8730 (anti-G(iα)), 3646 (anti-G(iα1)), 1521 (anti-G(iα2)), and 1518 (anti-G(iα3)), and of adenosine receptor-G protein complexes were detected by the binding of radioactive [3H]DPCPX. Results. Data indicate that [3H]DPCPX forms high- affinity complex with membrane-bound and solubilized forms of adenosine receptors from PE and NPE cells. Peptide-directed antisera against various G protein α subunits indicate that the A1 adenosine receptors from these cells are specifically coupled to G(iα) complexes. The results further indicate that the A1 adenosine receptors are predominantly associated to G(iα-3). Conclusion. The findings document a selective interaction between the α subunits of the inhibitory guanine nucleotide binding protein (G(i)) and A1 adenosine receptors in ocular ciliary epithelial cells in culture. The results suggest that adenosine receptors coupled to G(iα-3) may provide a site at which modulation of aqueous humor production in the ciliary epithelium occurs via the G protein-adenylyl cyclase pathway.

Original languageEnglish (US)
Pages (from-to)3057-3063
Number of pages7
JournalInvestigative Ophthalmology and Visual Science
Volume35
Issue number7
StatePublished - Jan 1 1994

Keywords

  • A adenosine receptors
  • G protein antisera
  • G(iα3)
  • [H]DPCPX
  • ciliary epithelia

ASJC Scopus subject areas

  • Ophthalmology
  • Sensory Systems
  • Cellular and Molecular Neuroscience

Fingerprint Dive into the research topics of 'Immunoprecipitation of A<sub>1</sub> adenosine receptor-GTP-binding protein complexes in ciliary epithelial cells'. Together they form a unique fingerprint.

  • Cite this