Calcium-permeable channels activated via guanine nucleotide-dependent mechanism in human carcinoma cells.
Patch clamp experiments on human carcinoma A431 cells have revealed two types of Ca2(+)-permeable channels, the activity of which can be increased by the application of non-hydrolyzable analogues of GTP to the intracellular side of the membrane. With 105 mM Ca2+ in recording pipette at 30-33 degrees C their unitary conductances (in pS) are 1.3 (SG-channels) and 2.4 (G-channels). G- and, possibly, SG-channels are activated from the extracellular side of the membrane with epidermal growth factor (EGF). The data are consistent with the hypothesis that both channels are activated via guanine nucleotide binding (G) proteins.
Mozhayeva
G N
GN
Institute of Cytology of Academy of Sciences of the USSR, Leningrad.
Naumov
A P
AP
Kuryshev
Y A
YA
D015220:Calcium Channels / Q000502:physiology*; D002277:Carcinoma / Q000503:physiopathology*; D004594:Electrophysiology; D004815:Epidermal Growth Factor / Q000494:pharmacology; D019204:GTP-Binding Proteins / Q000502:physiology*; D006150:Guanine Nucleotides / Q000502:physiology*; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000494:pharmacology; D006801:Humans; D066298:In Vitro Techniques; D014407:Tumor Cells, Cultured
D015220:Calcium Channels; D006150:Guanine Nucleotides; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D004815:Epidermal Growth Factor; D019204:GTP-Binding Proteins