Modulation of calcium mobilization by guanosine 5'-O-(2-thiodiphosphate) in Xenopus oocytes.
We investigated the effect of intracellular loading of the non-hydrolyzable guanosine 5'-diphosphate analogue GDP beta S on calcium mobilization by IP3 and on calcium influx in Xenopus oocytes. Assayed by two electrode voltage-clamp recording, GDP beta S-loaded oocytes demonstrated a marked augmentation of the fast component of the response to IP3 injection, an attenuation of the slow component and an increase in membrane calcium permeability. These effects on calcium mobilization suggest that GDP beta S may facilitate calcium translocation both across the plasma membrane and between different intracellular calcium pools.
Sealfon
S C
SC
Fishberg Center in Neurobiology, Mount Sinai School of Medicine, New York, NY 10029.
Mundamattom
S
S
Gillo
B
B
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002451:Cell Compartmentation / Q000187:drug effects; D002463:Cell Membrane Permeability / Q000187:drug effects; D004553:Electric Conductivity; D006150:Guanine Nucleotides / Q000494:pharmacology*; D006153:Guanosine Diphosphate / Q000031:analogs & derivatives / Q000494:pharmacology*; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism; D008094:Lithium / Q000378:metabolism; D008845:Microinjections; D009865:Oocytes / Q000378:metabolism*; D013873:Thionucleotides / Q000494:pharmacology*; D014982:Xenopus laevis
D006150:Guanine Nucleotides; D013873:Thionucleotides; D006153:Guanosine Diphosphate; C023427:guanosine 5'-O-(2-thiodiphosphate); D015544:Inositol 1,4,5-Trisphosphate; D008094:Lithium; D002118:Calcium