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Updated: Aug 25, 2026

Drug-induced Sensitization of Adenylyl Cyclase: Assay Streamlining and Miniaturization for Small Molecule and siRNA Screening Applications
09:39

Drug-induced Sensitization of Adenylyl Cyclase: Assay Streamlining and Miniaturization for Small Molecule and siRNA Screening Applications

Published on: January 27, 2014

Dexras1 inhibits adenylyl cyclase

T E Graham1, Z Qiao, R I Dorin

  • 1New Mexico Veterans Affairs Health Care System, Medical Service (111), Departments of Medicine and Biochemistry/Molecular Biology, University of New Mexico School of Medicine, 1501 San Pedro Blvd. SE, Albuquerque, NM 87108, USA.

Biochemical and Biophysical Research Communications
|March 17, 2004
PubMed

Insights

Dexras1 activates Gi signaling pathways independently of receptors. This activation inhibits adenylyl cyclase and CREB, suggesting a role in cAMP-PKA-CREB pathway regulation.

Area of Science:

  • Molecular Biology
  • Cell Signaling
  • Endocrinology

Background:

  • Dexras1 is a Ras family G protein activated by steroid hormones.
  • It acts as a receptor-independent activator of Gi/o family heterotrimeric G proteins.
  • Adenylyl cyclase activity is regulated by inhibitory G alpha subunits.

Purpose of the Study:

  • To investigate the effects of Dexras1 on adenylyl cyclase activity.
  • To determine the signaling pathways involved in Dexras1-mediated inhibition.
  • To assess Dexras1's impact on cAMP levels and CREB activation.

Main Methods:

  • Expression of Dexras1 and constitutively active Gsalpha.
  • Measurement of intracellular cAMP levels.
  • Assessment of CREB activation.
  • Use of pertussis toxin, RGS4, and dominant-interfering Gi alpha2 mutants.

Main Results:

  • Dexras1 expression significantly inhibited cAMP levels.
  • This inhibition was blocked by pertussis toxin and RGS4, but not by Gi alpha2 mutants.
  • Dexras1 decreased forskolin-stimulated CREB activation, an effect also blocked by RGS4.
  • Findings suggest activation of both G alpha and G beta gamma subunits of Gi.

Conclusions:

  • Dexras1 mediates ligand-independent activation of Gi signaling.
  • Dexras1 inhibits adenylyl cyclase and CREB activation via Gi pathways.
  • Dexras1 may play a physiological role in regulating the cAMP-PKA-CREB pathway.

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