Skip to main content

Mechanism of guanine nucleotide regulatory protein-mediated inhibition of adenylate cyclase. Studies with isolated subunits of transducin in a reconstituted system.

Publication ,  Journal Article
Cerione, RA; Staniszewski, C; Gierschik, P; Codina, J; Somers, RL; Birnbaumer, L; Spiegel, AM; Caron, MG; Lefkowitz, RJ
Published in: J Biol Chem
July 15, 1986

The retinal nucleotide regulatory protein, transducin, can substitute for the inhibitory guanine nucleotide-binding regulatory protein (Ni) in inhibiting adenylate cyclase activity in phospholipid vesicle systems. In the present work we have assessed the roles of the alpha (alpha T) and beta gamma (beta gamma T) subunit components in mediating this inhibition. The inclusion of either a preactivated alpha T . GTP gamma S (where GTP gamma S is guanosine 5'-O-(thiotriphosphate)) complex, or the beta gamma complex, in phospholipid vesicles containing the pure human erythrocyte stimulatory guanine nucleotide-binding regulatory protein (Ns) and the resolved catalytic moiety of bovine caudate adenylate cyclase (C) resulted in inhibition of the GppNHp-stimulated (where GppNHp is guanyl-5'-yl imidodiphosphate) activity (by approximately 30-60 and 90%, respectively, at 2 mM MgCl2). The inhibitions by both of these subunit species are specific for the Ns-stimulated activity with neither alpha T . GTP gamma S nor beta gamma T having any direct effect on the intrinsic activity of the catalytic moiety. Increasing the MgCl2 concentration in the assay incubations significantly decreases the inhibitions by both alpha T . GTP gamma S and beta gamma T. Similarly, when the pure hamster lung beta-adrenergic receptor is included in the lipid vesicles with Ns and C, the levels of inhibition of the GppNHp-stimulated activity by both alpha T . GTP gamma S and beta gamma T are reduced compared to those obtained in vesicles containing just Ns and C (but not stimulatory receptor). These inhibitions are reduced still further under conditions where the agonist stimulation of adenylate cyclase activity is maximal, i.e. when stimulating with isoproterenol plus GTP. In these cases the alpha T . GTP gamma S inhibitory effects are completely eliminated and the inhibitions observed with holotransducin can be fully accounted for by the beta gamma T complex. The ability of the beta-adrenergic receptor to relieve these inhibitions suggests that the receptor may remain coupled to Ns (or alpha s) during the activation of the regulatory protein and the stimulation of adenylate cyclase. These results also suggest that under physiological conditions the beta gamma subunit complex is primarily responsible for mediating the inhibition of adenylate cyclase activity.

Duke Scholars

Published In

J Biol Chem

ISSN

0021-9258

Publication Date

July 15, 1986

Volume

261

Issue

20

Start / End Page

9514 / 9520

Location

United States

Related Subject Headings

  • Transducin
  • Thionucleotides
  • Receptors, Adrenergic, beta
  • Membrane Proteins
  • Magnesium Chloride
  • Magnesium
  • Macromolecular Substances
  • Liposomes
  • Isoproterenol
  • Humans
 

Citation

APA
Chicago
ICMJE
MLA
NLM
Cerione, R. A., Staniszewski, C., Gierschik, P., Codina, J., Somers, R. L., Birnbaumer, L., … Lefkowitz, R. J. (1986). Mechanism of guanine nucleotide regulatory protein-mediated inhibition of adenylate cyclase. Studies with isolated subunits of transducin in a reconstituted system. J Biol Chem, 261(20), 9514–9520.
Cerione, R. A., C. Staniszewski, P. Gierschik, J. Codina, R. L. Somers, L. Birnbaumer, A. M. Spiegel, M. G. Caron, and R. J. Lefkowitz. “Mechanism of guanine nucleotide regulatory protein-mediated inhibition of adenylate cyclase. Studies with isolated subunits of transducin in a reconstituted system.J Biol Chem 261, no. 20 (July 15, 1986): 9514–20.
Cerione RA, Staniszewski C, Gierschik P, Codina J, Somers RL, Birnbaumer L, et al. Mechanism of guanine nucleotide regulatory protein-mediated inhibition of adenylate cyclase. Studies with isolated subunits of transducin in a reconstituted system. J Biol Chem. 1986 Jul 15;261(20):9514–20.
Cerione RA, Staniszewski C, Gierschik P, Codina J, Somers RL, Birnbaumer L, Spiegel AM, Caron MG, Lefkowitz RJ. Mechanism of guanine nucleotide regulatory protein-mediated inhibition of adenylate cyclase. Studies with isolated subunits of transducin in a reconstituted system. J Biol Chem. 1986 Jul 15;261(20):9514–9520.

Published In

J Biol Chem

ISSN

0021-9258

Publication Date

July 15, 1986

Volume

261

Issue

20

Start / End Page

9514 / 9520

Location

United States

Related Subject Headings

  • Transducin
  • Thionucleotides
  • Receptors, Adrenergic, beta
  • Membrane Proteins
  • Magnesium Chloride
  • Magnesium
  • Macromolecular Substances
  • Liposomes
  • Isoproterenol
  • Humans