title: The regulation of synaptic vesicle recycling by cGMP-dependent protein kinase type II in cerebellar granule cells under strong and sustained stimulation.
abstract: From the early periods of neurogenesis and migration, up until synaptogenesis, both nitric oxide (NO) and its downstream messenger, cGMP, are thought to influence the development of neurons. The NO/cGMP/cGMP-dependent protein kinase (cGK) pathway regulates the clustering and recruitment of synaptic proteins and vesicles to the synapse, adjusting the exoendocytic cycle to the intensity of activity and accelerating endocytosis following large-scale exocytosis. Here, we show that blockage of the N-methyl-D-aspartate receptor impairs the cycling of synaptic vesicles in a subset of boutons on cerebellar granule cells, an effect that was reversed by increasing cGMP. Furthermore, we demonstrate that presynaptic cGK type II (cGKII) plays a major role in this process. Using the FM1-43 dye to track vesicle recycling, we found that knockdown of cGKII and/or the application of a cGK inhibitor reduced the efficiency of synaptic vesicle recycling to a similar extent. Likewise, in cerebellar granule cells transfected with vGlut1-pHluorin to follow the exoendocytotic cycle, application of a cGK inhibitor slowed vesicle endocytosis when exocytosis was accelerated through strong and sustained stimulation. Additionally, ultrastructural analysis showed that cGKII knockdown or inhibition favored the formation of endosomal-like structures after strong and sustained stimulation. We conclude that cGKII controls the homeostatic balance of vesicle exocytosis and endocytosis in synaptic boutons of rat cerebellar granule cells.
authors: Departamento de Bioquímica, Facultad de Veterinaria, Universidad Complutense, Madrid 28040, Spain, and Instituto de Investigación Sanitaria del Hospital Clínico San Carlos, Hospital Clínico San Carlos, C/Profesor Martín Lagos s/n, Madrid 28040, Spain.
authors: Andrea
authors: A
authors: Collado-Alsina
authors: Departamento de Bioquímica, Facultad de Veterinaria, Universidad Complutense, Madrid 28040, Spain, and Instituto de Investigación Sanitaria del Hospital Clínico San Carlos, Hospital Clínico San Carlos, C/Profesor Martín Lagos s/n, Madrid 28040, Spain.
authors: Jorge
authors: J
authors: Ramírez-Franco
authors: Departamento de Bioquímica, Facultad de Veterinaria, Universidad Complutense, Madrid 28040, Spain, and Instituto de Investigación Sanitaria del Hospital Clínico San Carlos, Hospital Clínico San Carlos, C/Profesor Martín Lagos s/n, Madrid 28040, Spain.
authors: José
authors: J
authors: Sánchez-Prieto
authors: Departamento de Bioquímica, Facultad de Veterinaria, Universidad Complutense, Madrid 28040, Spain, and Instituto de Investigación Sanitaria del Hospital Clínico San Carlos, Hospital Clínico San Carlos, C/Profesor Martín Lagos s/n, Madrid 28040, Spain mitorres@vet.ucm.es.
authors: Magdalena
authors: M
authors: Torres
mesh_terms: D000818:Animals; D002531:Cerebellum / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D062967:Cyclic GMP-Dependent Protein Kinase Type II / Q000235:genetics / Q000378:metabolism*; D004705:Endocytosis / Q000187:drug effects / Q000502:physiology; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D005089:Exocytosis / Q000187:drug effects / Q000502:physiology; D006706:Homeostasis / Q000187:drug effects / Q000502:physiology; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors / Q000378:metabolism; D013572:Synaptic Vesicles / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*
chemical_list: D018691:Excitatory Amino Acid Antagonists; D016194:Receptors, N-Methyl-D-Aspartate; D062967:Cyclic GMP-Dependent Protein Kinase Type II
keywords: cGMP signaling; cerebellar granule cells; endocytosis; retrograde messenger; vesicle recycling