Cyclic AMP influences protein synthesis in larval brains of Drosophila melanogaster

The protein synthesis in dissected whole larval brains of Drosophila melanogaster has been monitored by [35S] methionine incorporation, as revealed by two-dimensional gel-electrophoresis and fluorography. In wild type brains, drugs known to increase cAMP level increased the labelling of at least two proteins in the Mr range 30 to 120 kD and pI range 4.8 to 6.2. One of these proteins, Mr = 78 kD and pI = 5.9, was also enhanced in the dunceM11 memory-mutant, which has an elevated cAMP level, whereas it was hardly affected in the rutabaga memory-mutant, which has a subnormal cAMP level. It is suggested that cAMP-induced alterations in protein composition and/or turnover of nerve cells may contribute to the development of memory deficit in the dunce strains.