TY  - JOUR
AU  - Silbern, Ivan
AU  - Pan, Kuan-Ting
AU  - Fiosins, Maksims
AU  - Bonn, Stefan
AU  - Rizzoli, Silvio O
AU  - Fornasiero, Eugenio F
AU  - Urlaub, Henning
AU  - Jahn, Reinhard
TI  - Protein Phosphorylation in Depolarized Synaptosomes: Dissecting Primary Effects of Calcium from Synaptic Vesicle Cycling.
JO  - Molecular & cellular proteomics
VL  - 20
SN  - 1535-9476
CY  - Bethesda, Md.
PB  - The American Society for Biochemistry and Molecular Biology
M1  - DZNE-2021-00764
SP  - 100061
PY  - 2021
AB  - Synaptic transmission is mediated by the regulated exocytosis of synaptic vesicles. When the presynaptic membrane is depolarized by an incoming action potential, voltage-gated calcium channels open, resulting in the influx of calcium ions that triggers the fusion of synaptic vesicles (SVs) with the plasma membrane. SVs are recycled by endocytosis. Phosphorylation of synaptic proteins plays a major role in these processes, and several studies have shown that the synaptic phosphoproteome changes rapidly in response to depolarization. However, it is unclear which of these changes are directly linked to SV cycling and which might regulate other presynaptic functions that are also controlled by calcium-dependent kinases and phosphatases. To address this question, we analyzed changes in the phosphoproteome using rat synaptosomes in which exocytosis was blocked with botulinum neurotoxins (BoNTs) while depolarization-induced calcium influx remained unchanged. BoNT-treatment significantly alters the response of the synaptic phoshoproteome to depolarization and results in reduced phosphorylation levels when compared with stimulation of synaptosomes by depolarization with KCl alone. We dissect the primary Ca2+-dependent phosphorylation from SV-cycling-dependent phosphorylation and confirm an effect of such SV-cycling-dependent phosphorylation events on syntaxin-1a-T21/T23, synaptobrevin-S75, and cannabinoid receptor-1-S314/T322 on exo- and endocytosis in cultured hippocampal neurons.
KW  - Animals
KW  - Botulinum Toxins: pharmacology
KW  - Calcium: metabolism
KW  - Clostridium botulinum
KW  - Glutamic Acid: metabolism
KW  - HeLa Cells
KW  - Hippocampus: cytology
KW  - Humans
KW  - Neurons: metabolism
KW  - Neurotoxins: pharmacology
KW  - Phosphoproteins: metabolism
KW  - Phosphorylation
KW  - Proteome
KW  - R-SNARE Proteins: metabolism
KW  - Rats, Wistar
KW  - Receptor, Cannabinoid, CB1: metabolism
KW  - Synaptic Vesicles: metabolism
KW  - Synaptosomes: metabolism
KW  - Syntaxin 1: metabolism
KW  - Endocytosis (Other)
KW  - SNARE (Other)
KW  - botulinum neurotoxins (Other)
KW  - cannabinoid receptor (Other)
KW  - exocytosis (Other)
KW  - phosphomimetic studies (Other)
KW  - phosphorylation (Other)
KW  - synapse (Other)
KW  - synaptobrevin (Other)
KW  - syntaxin (Other)
LB  - PUB:(DE-HGF)16
C6  - pmid:33582301
C2  - pmc:PMC7995663
DO  - DOI:10.1016/j.mcpro.2021.100061
UR  - https://pub.dzne.de/record/155596
ER  -