Voltage-dependent calcium channel beta-subunits in combination with alpha 1 subunits, have a GTPase activating effect to promote the hydrolysis of GTP by G alpha o in rat frontal cortex

FEBS Lett. 1995 Aug 14;370(1-2):135-40. doi: 10.1016/0014-5793(95)00813-o.


The dihydropyridine-sensitive calcium channel agonist (-)-BayK 8644 was found to produce an enhancement of the intrinsic hydrolysis of GTP by Go in rat frontal cortex membranes. An anti-calcium channel beta-subunit antiserum abolished the (-)-BayK 8644-stimulated hydrolysis of GTP by Go and reduced the dihydropyridine binding capacity of the cortical membranes. A peptide which mimics the beta-subunit binding domain of the calcium channel complex, also attenuated (-)-BayK 8644 activation of GTPase. This study suggests that the calcium channel beta-subunit is the principal component of the channel complex involved in linking dihydropyridine agonist binding to enhanced hydrolysis of GTP by Go. This may be a mechanism by which calcium channels can normally act to limit the duration of a G-protein modulatory signal.

MeSH terms

  • 3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester / pharmacology*
  • Amino Acid Sequence
  • Animals
  • Binding Sites
  • Calcium Channels / drug effects
  • Calcium Channels / physiology*
  • Cell Membrane / metabolism
  • Dihydropyridines / metabolism
  • Enzyme Activation
  • Frontal Lobe / drug effects
  • Frontal Lobe / metabolism*
  • GTP Phosphohydrolases / metabolism*
  • GTP-Binding Proteins / metabolism*
  • Guanosine Triphosphate / metabolism*
  • Kinetics
  • Molecular Sequence Data
  • Peptide Fragments / chemical synthesis
  • Peptide Fragments / chemistry
  • Rats


  • Calcium Channels
  • Dihydropyridines
  • Peptide Fragments
  • 3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester
  • 1,4-dihydropyridine
  • Guanosine Triphosphate
  • GTP Phosphohydrolases
  • GTP-Binding Proteins