Synaptic modulation by a Drosophila neuropeptide is motor neuron-specific and requires CaMKII activity.
The Drosophila FMRFamide-related peptide, DPKQDFMRFamide modulates synaptic transmission at the larval neuromuscular junction. The amplitude of excitatory junctional potentials (EJPs) produced by the selective stimulation of motor neuron MN6/7-Ib increases following application of 1 microM DPKQDFMRFamide. EJPs elicited by stimulating motor neuron MNSNb/d-Is, however, exhibit no significant increase with the same concentration of neuropeptide. The mechanisms underlying the modulatory effects of DPKQDFMRFamide were examined using a combination of pharmacological and genetic methods. Three independent lines of evidence implicate CaMKII as an essential effector protein or part of the signal transduction pathway. The effect of the neuropeptide is suppressed by 1 microM KN-93 (CaMKII inhibitor) and by heat-shock induced expression of a CaMKII inhibitor. A heterozygous CaM kinase mutant responds poorly to the peptide.
Dunn
Tyler W
TW
Department of Biological Sciences, Brock University, 500 Glenridge Avenue, St. Catharines, Ont., Canada L2S 3A1.
Mercier
A Joffre
AJ
D000818:Animals; D001596:Benzylamines / Q000494:pharmacology; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism*; D004330:Drosophila / Q000502:physiology*; D004558:Electric Stimulation; D007814:Larva; D009046:Motor Neurons / Q000187:drug effects* / Q000502:physiology; D009469:Neuromuscular Junction / Q000187:drug effects / Q000502:physiology*; D009479:Neuropeptides / Q000378:metabolism / Q000494:pharmacology*; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D013449:Sulfonamides / Q000494:pharmacology; D009435:Synaptic Transmission / Q000187:drug effects* / Q000502:physiology; D013997:Time Factors; D000096926:Benzenesulfonamides
D001596:Benzylamines; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D009479:Neuropeptides; D047428:Protein Kinase Inhibitors; D013449:Sulfonamides; C425780:KN 92; C072105:KN 93; D000096926:Benzenesulfonamides