The G protein G13 mediates inhibition of voltage-dependent calcium current by bradykinin.
In neuroblastoma-glioma hybrid cells, bradykinin has dual modulatory effects on ion channels: it activates a K+ current as well as inhibits the voltage-dependent Ca2+ current (ICa,V). Both of these actions are mediated by pertussis toxin-insensitive G proteins. Antibodies raised against the homologous Gq and G11 proteins suppress only the activation of the K+ current; this suggested that at least two distinct G protein pathways transduce diverse effects of this transmitter. Here, we show that the inhibition of ICa,V by bradykinin is suppressed selectively by intracellular application of antibodies specific for G13. This novel G protein may play a general role in the inhibition of ICa,V by pathways resistant to pertussis toxin.
Wilk-Blaszczak
M A
MA
Department of Pharmacology, University of Texas, Southwestern Medical Center, Dallas 75235.
Singer
W D
WD
Gutowski
S
S
Sternweis
P C
PC
Belardetti
F
F
D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western; D001920:Bradykinin / Q000502:physiology*; D002118:Calcium / Q000502:physiology*; D002460:Cell Line; D004743:Enkephalin, Leucine / Q000494:pharmacology; D019204:GTP-Binding Proteins / Q000502:physiology*; D006822:Hybrid Cells; D007158:Immunologic Techniques; D066298:In Vitro Techniques; D015640:Ion Channel Gating; D008564:Membrane Potentials; D008969:Molecular Sequence Data; D009474:Neurons / Q000502:physiology; D010455:Peptides / Q000737:chemistry / Q000276:immunology / Q000494:pharmacology; D037342:Pertussis Toxin; D051381:Rats; D010566:Virulence Factors, Bordetella / Q000494:pharmacology; D020866:omega-Conotoxin GVIA
D010455:Peptides; D010566:Virulence Factors, Bordetella; D004743:Enkephalin, Leucine; D020866:omega-Conotoxin GVIA; D037342:Pertussis Toxin; D019204:GTP-Binding Proteins; D001920:Bradykinin; D002118:Calcium