Adenylate cyclase in washed, crude membrane fractions prepared from the Drosophila conditioning mutant, rutabaga, displays an altered responsiveness to Ca2+. The results are of interest since the modulation of adenylate cyclase activity by Ca2+ has recently been suggested to play a role in molecular events that underlie memory formation.
The High Resolution Fly's Eye (HiRes) experiment has observed the GZK cutoff. HiRes' measurement of the flux of cosmic rays shows a sharp suppression at an energy of 6 × 10 19 eV, exactly the expected cutoff energy. We observe the " Ankle " of the cosmic ray spectrum as well, at an energy of 4 × 10 18 eV. We describe the experiment, data collection,… (More)
The activity of adenylate cyclase in homogenates prepared from the Drosophila memory mutant rutabaga is lower than normal. The effect is most pronounced in washed membranes prepared from the abdomen, in which the enzyme displays both a lower Vmax and a higher Km. Analysis of the effect of divalent cations suggests a lesion in the responsiveness of the… (More)
[3H]Dihydroergocryptine ([3H]DHE) binds to a particulate preparation from Drosophila melanogaster heads at a level of 2.4 +/- 0.4 pmol/mg protein, with an apparent dissociation constant of 2.0 +/- 0.5 nM. The binding sites are inactivated by heat, pronase treatment, and sulfhydryl and disulfide reagents. [3H]DHE binding is inhibited by low concentrations of… (More)
Adenylate cyclase in homogenates of Drosophila melanogaster is heterogeneous with respect to its affinity toward MgATP and its subcellular distribution. Km values for MgATP range, under similar assay conditions, from approximately 10(-5) M to approximately 10(-3) M, depending on the body region and on the subcellular localization of the enzyme. The majority… (More)