G-protein modulation of neuronal class E (alpha(1E)) calcium channel expressed in GH(3) cells

GH(3) cell lines stably expressing alpha(1E) channel were established and the modulation of this channel by G-protein through membrane-delimited pathways was studied. alpha(1E) channel expressed in GH(3) cells showed slowing of activation and reduction of current amplitude by the application of carbachol or somatostatin. Both of these effects caused by these agents were pertussis toxin (PTX) sensitive and voltage dependent. Dialysis of the cell interior with GTP gamma S mimicked the action of these externally applied neurotransmitters, indicating that the alpha(1E) channel is modulated by the PTX sensitive G-protein(s) through the membrane-delimited pathway but not by the PTX insensitive pathway that has been observed in alpha(1A) channel expressed in GH(3) cells. Thus different types of neuronal Ca2+ channels can be modulated not only by a similar mechanism but also by a different mechanism conferring a multilateral regulation of Ca2+ entry through these channels. (C) 1996 Academic Press, Inc.