biostudies-literatureCampbell JRNEI NIH HHSNational Institutes of Health587072https://www.ebi.ac.uk/biostudies/studies/S-EPMC7606922biostudies-literatureUnknown14Neurotransmitter release at retinal ribbon-style synapses utilizes a specialized t-SNARE protein called syntaxin3B (STX3B). In contrast to other syntaxins, STX3 proteins can be phosphorylated <i>in vitro</i> at T14 by Ca^2+/calmodulin-dependent protein kinase II (CaMKII). This modification has the potential to modulate SNARE complex formation required for neurotransmitter release in an activity-dependent manner. To determine the extent to which T14 phosphorylation occurs <i>in vivo</i> in the mammalian retina and characterize the pathway responsible for the <i>in vivo</i> phosphorylation of T14, we utilized quantitative immunofluorescence to measure the levels of STX3 and STX3 phosphorylated at T14 (pSTX3) in the synaptic terminals of mouse retinal photoreceptors and rod bipolar Frontiers in cellular neurosciencePhosphorylation of the Retinal Ribbon Synapse Specific t-SNARE Protein Syntaxin3B Is Regulated by Light via a Ca^{2 +}-Dependent Pathway.PMC7606922P30 EY028102R01 EY012128P30 EY010608Liu XCampbell JRLi HKozhemyakin MJanz RWang YHunt AJHeidelberger RfalsePhosphorylation of the Retinal Ribbon Synapse Specific t-SNARE Protein Syntaxin3B Is Regulated by Light via a Ca^{2 +}-Dependent Pathway.Neurotransmitter release at retinal ribbon-style synapses utilizes a specialized t-SNARE protein called syntaxin3B (STX3B). In contrast to other syntaxins, STX3 proteins can be phosphorylated <i>in vitro</i> at T14 by Ca^2+/calmodulin-dependent protein kinase II (CaMKII). This modification has the potential to modulate SNARE complex formation required for neurotransmitter release in an activity-dependent manner. To determine the extent to which T14 phosphorylation occurs <i>in vivo</i> in the mammalian retina and characterize the pathway responsible for the <i>in vivo</i> phosphorylation of T14, we utilized quantitative immunofluorescence to measure the levels of STX3 and STX3 phosphorylated at T14 (pSTX3) in the synaptic terminals of mouse retinal photoreceptors and rod bipolar 2020-01-01T00:00:00Z20202025-04-05T11:25:24.38Z2020-11-22T09:59:39ZS-EPMC76069223319232910.3389/fncel.2020.587072