| Annotated protein: | Synaptotagmin-3 (Synaptotagmin III) (SytIII). Gene symbol: SYT3. Taxonomy: Rattus norvegicus (Rat). Uniprot ID: P40748 |
| antibody wiki: | |
| SynGO gene info: | SynGO data @ SYT3 |
| Ontology domain: | Cellular Component |
| SynGO term: | integral component of synaptic membrane (GO:0099699) |
| Synapse type(s): | brain retina |
| Annotated paper: | Butz S, et al. "The subcellular localizations of atypical synaptotagmins III and VI. Synaptotagmin III is enriched in synapses and synaptic plasma membranes but not in synaptic vesicles" J Biol Chem. 1999 Jun 25;274(26):18290-6 PMID:10373432 |
| Figure(s): | Fig. 3, Fig. 5, Fig. 6-8 |
| Annotation description: | Butz et al report in this paper enrichment of synaptotagmin-3 in synaptic plasma membranes. The authors generate a specific antibody and verify it by using overexpressed synaptotagmin-3 in COS cells and brain material from a syt-3 KO mouse (stated as unpublished). Immunoblotting of fractions from rat brain subfractionation shows no enrichment of synaptogmin-3 (though remaining detectable) in synaptic vesicle fractions. In contrast, the protein is highly enriched in the synaptic membrane fraction. Additionally, in order to test whether synaptotagmin-3 is a SV protein, the authors immunoblot ([125]I-secondary-antibody-detection) synaptosomes, crude SV fraction and CPG-isolated SVs for a set of vesicular proteins and observe decrease in synaptotagmin-3 signal in CPG-SVs compared to that of the other SV marker proteins. Furthermore, synaptic vesicle immunoisolation via anti-synaptotagmin-1 or anti-synaptobrevin 2 antibodies and immunodetection as mentioned above reveals no signal for synaptotagmin-3 in the immunoisolates. This data suggests that synaptotagmin-3 is not on synaptic vesicles, but rather localized to synaptic plasma membranes. This finding is consistent with data from Takamori et al (Cell, 2006). 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: | Microscopy (generic) Western blot Biochemical fractionation (generic) Radioimmunoassay |
| 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: | Mizuta et al isolate cDNA clone encoding for synaptotagmin and detect for first time mRNA of synaptotagmin 3 in RNA pool from cerebrum and cerebellum. @ PMID:8163462 Takamori et al do not detect synaptotagmin-3 in their proteomic analysis of CPG-SVs, what is consistent with previous findings that the protein is rather enriched on synaptic plasma membranes. @ PMID:17110340 |
| SynGO annotation ID: | 1144 |
| Dataset release (version): | 20231201 |
| View annotation as GO-CAM model: |  |