| Annotated protein: | Synaptotagmin-4 (Synaptotagmin IV) (SytIV). Gene symbol: SYT4. Taxonomy: Mus musculus (Mouse). Uniprot ID: P40749 |
| antibody wiki: | |
| SynGO gene info: | SynGO data @ SYT4 |
| Ontology domain: | Cellular Component |
| SynGO term: | integral component of neuronal dense core vesicle membrane (GO:0099066) |
| Synapse type(s): | hypothalamus |
| Annotated paper: | Zhang Z, et al. "Synaptotagmin IV: a multifunctional regulator of peptidergic nerve terminals" Nat Neurosci. 2009 Feb;12(2):163-71 PMID:19136969 |
| Figure(s): | Fig.1, Fig. 2 |
| Annotation description: | In the light of controversial reports on the localization and function of mammalian syt4, Zhang et al attempt to determine the protein subcellular localization in peptidergic nerve terminals of mouse. Zhang et al determine the expression pattern of the protein in cortex, cerebellum, hippocampus, striatum and pituitary gland and find high abundance of the protein in posterior and anterior pituitary - neuro- and adenohypophysis, respectively. In addition, the specificity of the antibody for immunoblotting is verified by protein extracts from syt-4 KO animals (fig. 1A and B). The authors perform immuno-organelle isolation of vesicles from rat anterior and posterior pituitary (rat is preferred over mouse in order to obtain more material) using synaptophysin and synaptotagmin I antibodies and observe co-enrichment of synaptotagmin IV with synaptophysin and syt I-positive vesicles (Fig 1), suggesting that the protein is localized to both microvesicles and dense-core vesicles. These findings are supported by immunogold EM analysis which reveals synaptotagmin 4 association with microvesicles and DCVs at WT mice nerve terminals of the neurophypophysis (Fig. 2). 6/2/2018 Pim - Based on the known transmembrane topology of the protein, the "integral component of ... membrane" term was chosen. |
| Evidence tracking, Biological System: | Intact tissue |
| Evidence tracking, Protein Targeting: | Antibody (detection) |
| Evidence tracking, Experiment Assay: | Electron Microscopy Western blot Biochemical fractionation (generic) IP + WB/MSMS |
| Annotator(s): | Momchil Ninov (ORCID:0000-0002-0808-7003) Mahdokht Kohansalnodehi (ORCID:0000-0002-3898-5197) Reinhard Jahn (ORCID:0000-0003-1542-3498) |
| Lab: | Department of Neurobiology, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany |
| Additional literature: | The paper provides evidence for the localization of syt4 to postsynaptic brain-derived neurotrophic factor (BDNF)-containing vesicles in hippocampal neurons (Fig. 1 and Suppl Fig 1). Furthermore, time-lapse experiments on hippocampal neurons transfected with mCherry-syt 4 and BDNF-GFP show co-trafficking of both proteins (Suppl Fig 2) and deliver additional evidence for their localization to same vesicles. Additionally, the data shows that syt 4 is not localized to synaptic vesicles (Fig. 1C and Fig. 4). @ PMID:19448629 In a screen for cell-type specific immediate early genes in induced rat PC12 cells, the authors isolate a cDNA clone encoding for rat synaptotagmin IV and provide predicted amino acid sequence with putative transmembrane regions indicated. Furthermore, Vician et al show that syt-4 mRNA transcripts are induced by forskolin, calcium ionophore, potassium depolarization and ATP in PC12 cells and that kainic acid-induced seizures increase syt4 mRNA in rat hippocampus and piriform cortex. @ PMID:7892240 |
| SynGO annotation ID: | 1147 |
| Dataset release (version): | 20231201 |
| View annotation as GO-CAM model: |  |