TY - JOUR
T1 - Stimulation of epinephrine sensitive fat cell adenylate cyclase by cytosol
T2 - effect of cholera toxin
AU - Ganguly, U.
AU - Greenough, W. B.
PY - 1975
Y1 - 1975
N2 - Cytosol prepared from rat epididymal fat cells by centrifugation at 100,000 x g for 1 hr was found to enhance the basal and epinephrine sensitive adenylate cyclase [EC 4.6.1.1; ATP pyrophosphate lyase (cyclizing)] of fat cell ghosts. Cholera toxin also stimulated adenylate cyclase and increased the response to epinephrine in fat cells. A possible relationship between the adenylate cyclase modifying activities of cytosol and the effects of cholera toxin was sought. Cytosol from freshly pepared fat cells added to ghosts prepared from cells that had been exposed to toxin for varying periods showed a progressive loss of responsiveness to cytosol epinephrine enhancing activity. The effect appeared within 15 min after toxin exposure, a full 30 min before any direct effect to toxin on adenylate cyclase was seen. Since exposure to toxin decreased mmbrane response to cytosol epinephrine enhancing activity, the possibility that epinephrine enhancing activity in cytosol might be altered by toxin was explored. Cytosol from cells exposed to toxin for varying periods lost epinephrine enhancing activity to an appreciable degree within 15 min. Examination of these early events after exposure to toxin should clarify the way in which this bacterial substance affects mammalian cells. The cytosol epinephrine enhancing activity was destroyed by boiling for 3 min and was partially inactivated by trypsin. It was nondialyzable and stable at -70° .
AB - Cytosol prepared from rat epididymal fat cells by centrifugation at 100,000 x g for 1 hr was found to enhance the basal and epinephrine sensitive adenylate cyclase [EC 4.6.1.1; ATP pyrophosphate lyase (cyclizing)] of fat cell ghosts. Cholera toxin also stimulated adenylate cyclase and increased the response to epinephrine in fat cells. A possible relationship between the adenylate cyclase modifying activities of cytosol and the effects of cholera toxin was sought. Cytosol from freshly pepared fat cells added to ghosts prepared from cells that had been exposed to toxin for varying periods showed a progressive loss of responsiveness to cytosol epinephrine enhancing activity. The effect appeared within 15 min after toxin exposure, a full 30 min before any direct effect to toxin on adenylate cyclase was seen. Since exposure to toxin decreased mmbrane response to cytosol epinephrine enhancing activity, the possibility that epinephrine enhancing activity in cytosol might be altered by toxin was explored. Cytosol from cells exposed to toxin for varying periods lost epinephrine enhancing activity to an appreciable degree within 15 min. Examination of these early events after exposure to toxin should clarify the way in which this bacterial substance affects mammalian cells. The cytosol epinephrine enhancing activity was destroyed by boiling for 3 min and was partially inactivated by trypsin. It was nondialyzable and stable at -70° .
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U2 - 10.1073/pnas.72.9.3561
DO - 10.1073/pnas.72.9.3561
M3 - Article
C2 - 1059143
AN - SCOPUS:0016786279
SN - 0027-8424
VL - 72
SP - 3561
EP - 3564
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 9
ER -