Inhibition by EDTA and enhancement by divalent cations or polyamines of the dithiothreitol-induced activation of adenylate cyclase in the cellular slime mold, Dictyostelium discoideum.
Binding of cAMP to cell surface receptors evokes the transient activation of of adenylate cyclase in Dictyostelium discoideum. Dithiothreitol is also known as an activator of this enzyme. We found that the dithiothreitol-induced activation was specifically enhanced by extracellular polyamines or divalent cations. Furthermore, EDTA, a chelating agent of divalent cations, completely inhibited the dithiothreitol-induced activation of adenylate cyclase while EDTA did not inhibit the cAMP-induced activation. The inhibition was nullified by addition of polyamines or divalent cations. These results suggest that extracellular polyamines and divalent cations play a specific role in the dithiothreitol-induced activation of adenylate cyclase.
Oyama
M
M
Laboratory of Biology, Himeji Institute of Technology, Hyogo, Japan.
Kubota
K
K
D000262:Adenylyl Cyclases / Q000187:drug effects*; D002133:Calcium Sulfate / Q000494:pharmacology; D002413:Cations, Divalent / Q000494:pharmacology; D000242:Cyclic AMP / Q000494:pharmacology; D004023:Dictyostelium / Q000187:drug effects* / Q000201:enzymology; D004229:Dithiothreitol / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D004492:Edetic Acid / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D011073:Polyamines / Q000494:pharmacology
D002413:Cations, Divalent; D011073:Polyamines; D004492:Edetic Acid; D000242:Cyclic AMP; D000262:Adenylyl Cyclases; D004229:Dithiothreitol; D002133:Calcium Sulfate