How do G proteins directly control neuronal Ca2+ channel function?
Ca2+ entry into neuronal cells is modulated by the activation of numerous G-protein-coupled receptors (GPCRs). Much effort has been invested in studying direct G-protein-mediated inhibition of voltage-dependent CaV2 Ca2+ channels. This inhibition occurs through a series of convergent modifications in the biophysical properties of the channels. An integrated view of the structural organization of the Gbetagamma-dimer binding-site pocket within the channel is emerging. In this review, we discuss how variable geometry of the Gbetagamma binding pocket can yield distinct sets of channel inhibition. In addition, we propose specific mechanisms for the regulation of the channel by G proteins that take into account the regulatory input of each Gbetagamma binding element.
De Waard
Michel
M
Laboratoire Canaux Calciques, Fonctions et Pathologies, Inserm U607, CEA, DRDC, 17 rue des Martyrs, 38054 Grenoble Cedex 09, France. mdewaard@cea.fr
Hering
Julien
J
Weiss
Norbert
N
Feltz
Anne
A
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D015220:Calcium Channels / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D019204:GTP-Binding Proteins / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009474:Neurons / Q000378:metabolism*; D011485:Protein Binding; D017386:Sequence Homology, Amino Acid
D015220:Calcium Channels; D019204:GTP-Binding Proteins