Defective Responsiveness of Adenylate Cyclase to Forskolin in the Drosophila Memory Mutant rutabaga
作者:
DudaiYadin,
SherBruria,
SegalDaniel,
YovellYoram,
期刊:
Journal of Neurogenetics
(Taylor Available online 1985)
卷期:
Volume 2,
issue 6
页码: 365-380
ISSN:0167-7063
年代: 1985
DOI:10.3109/01677068509101423
出版商: Taylor&Francis
关键词: adenylate cyclase;memory mutation;Drosophila melanogaster;forskolin
数据来源: Taylor
摘要:
TheDrosophilamemory mutantrutabaga(rut) has been previously shown to have a defective subpopu-lation (or functional state) of the enzyme adenylate cyclase. We report here that the reduced adenylate cyclase activity is also associated with a defective responsiveness of the enzyme to forskolin. Forskolin activation isotherms of the enzyme in normal membranes reveal low- and high-affinity forskolin-interacting components; the residual enzyme in the mutant shows a smaller proportion of the high-affinity response. In addition, in mutant membrane preparations, forskolin fails to shift theKmof the enzyme for free Mg2+and for MgATP, in contrast to the situation in the normal tissue. The defect in the responsiveness to forskolin inrutis even more pronounced in a Lubrol-solubilized enzyme preparation, and is due to intrinsic properties of the cyclase system rather than to the absence (or presence) of a soluble, or detergent solubilized, factor inrut. The reduced forskolin responsiveness maps to the X chromosomal segment 12F5-6 to 13A1-5, within the region previously reported to span the locus that controls both the abortive memory and the lack of Ca2+-stimulation of adenylate cyclase inrut17. The possible relevance of the findings to postulated molecular mechanisms of short-term memory formation is discussed.
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