Cookies on this website

We use cookies to ensure that we give you the best experience on our website. If you click 'Accept all cookies' we'll assume that you are happy to receive all cookies and you won't see this message again. If you click 'Reject all non-essential cookies' only necessary cookies providing core functionality such as security, network management, and accessibility will be enabled. Click 'Find out more' for information on how to change your cookie settings.

Sustained neurotransmission requires the tight coupling of synaptic vesicle (SV) exocytosis and endocytosis. The mechanisms underlying this coupling are poorly understood. We tested the hypothesis that a cGMP-dependent protein kinase (PKG), encoded by the foraging (for) gene in Drosophila melanogaster, is critical for this process using a for null mutant, genomic rescues and tissue-specific rescues. We uncoupled the exocytic and endocytic functions of FOR in neurotransmission using a temperature-sensitive shibire mutant in conjunction with fluorescein-assisted light inactivation of FOR. We discovered a dual role for presynaptic FOR, in which FOR inhibits SV exocytosis during low-frequency stimulation by negatively regulating presynaptic Ca2+ levels and maintains neurotransmission during high-frequency stimulation by facilitating SV endocytosis. Additionally, glial FOR negatively regulated nerve terminal growth through TGF-β signalling, and this developmental effect was independent of the effects of FOR on neurotransmission. Overall, FOR plays a critical role in coupling SV exocytosis and endocytosis, thereby balancing these two components to maintain sustained neurotransmission.

Original publication




Journal article


J Cell Sci

Publication Date





Endocytosis, Exocytosis, Neurotransmitter release, Presynaptic, Synaptic transmission, Animals, Cyclic GMP-Dependent Protein Kinases, Drosophila Proteins, Drosophila melanogaster, Endocytosis, Exocytosis, Mutation, Neuromuscular Junction, Presynaptic Terminals, Signal Transduction, Synaptic Transmission, Synaptic Vesicles, Transforming Growth Factor beta