| Annotated protein: | Calsyntenin-3 (Cst-3) (Alcadein-beta). Gene symbol: CLSTN3. Taxonomy: Mus musculus (Mouse). Uniprot ID: Q99JH7 |
| antibody wiki: | |
| SynGO gene info: | SynGO data @ CLSTN3 |
| Ontology domain: | Biological Process |
| SynGO term: | regulation of presynapse assembly (GO:1905606) |
| Synapse type(s): | hippocampus, GABAergic hippocampus, glutamatergic neocortex, GABAergic |
| Annotated paper: | Um JW, et al. "Calsyntenins function as synaptogenic adhesion molecules in concert with neurexins" Cell Rep. 2014 Mar 27;6(6):1096-1109 PMID:24613359 |
| Figure(s): | Fig.1, 4-6 |
| Annotation description: | Fig.1: "CST-3 Induces Presynaptic Differentiation in Heterologous Synapse-formation Assays" - "To determine the synaptic function(s) of CST-3, we first examined whether all three CSTs trigger presynaptic differentiation in heterologous synapse-formation assays using HEK293T cells expressing each CST protein. ... CST-3, but not CST-1 or CST-2, strongly induced synapsin clustering (Figures 1A and 1B)." - "CST-3 induced the synaptic clustering of both the excitatory presynaptic marker VGLUT1 (vesicular glutamate transport 1) and the inhibitory presynaptic marker GAD67 (glutamic acid decarboxylase, 67 kDa), but not the excitatory postsynaptic marker PSD-95 (postsynaptic density, 95 kDa) (Figures 1A and 1B). These results suggest that CST-3 is a novel postsynaptogenic factor that induces presynaptic differentiation." Fig.4: "Knockdown of All Three CSTs, but Not Individual CST Isoform Alone, Reduces Synapse Density and Soma Size in Cultured Neurons" - "We next investigated whether the single KD of CST-1, CST-2, or CST-3 altered the synapse number in cultured mouse hippocampal neurons...We observed that single KD of each CST did not alter synapse density, synapse size, synapse strength or soma size (Figures S2B-S2E)...Using the CST-TKD vector, which successfully suppressed the mRNA levels of all three CSTs (Figure 4C), we examined whether CSTs are functionally redundant and essential for synapse maintenance in cultured hippocampal neurons (Figures 4 and S3). Strikingly, CST-TKD significantly decreased the number of inhibitory synapses, assessed using inhibitory synaptic markers (GAD67 and gephyrin) (Figures 4D, 4E and S3). CST-TKD also significantly reduced the number of excitatory presynaptic puncta (labeled by VGLUT1), but not excitatory postsynaptic puncta (labeled by Homer1) (Figures 4D, 4E and S3)." Fig.5: "CST Knockdown Impairs Inhibitory, but Not Excitatory, Synaptic Transmission In Vivo" - " Strikingly, measurements of miniature excitatory postsynaptic currents (mEPSCs) showed that CST-TKD did not alter excitatory synaptic transmission (Figures S5C and S5E-S5F). In contrast, CST-TKD caused a significant decrease in the frequency, but not the amplitude, of miniature inhibitory postsynaptic currents (mIPSCs) (Figures S5D and S5G-S5H). These results suggest that, although CSTs are required for the maintenance of both excitatory and inhibitory synapses, these molecules are predominantly involved in regulating inhibitory synaptic functions." Fig.6: "Nrxs Are Functional Receptors For CST-3 To Promote Presynaptic Development" - " We asked whether Nrxs are required for the synaptogenic activities of CST-3. We infected cultured neurons with lentiviruses expressing either an empty shRNA vector (Control) or a triple KD shRNA construct for Nrxs (Nrx-TKD). Subsequently, we performed heterologous synapse-formation assays using infected neurons and HEK293T cells expressing CST-3, neuroligin-1 (NL1; positive control) or Slitrk1 (negative control) (Figures 6G and 6H). Upon Nrx-TKD, we observed the absence of CST-3 induced synapsin clustering on contacting axons of co-cultured hippocampal neurons. " Notes: - Calcystenin-3 is a postsynaptic protein (see PMID:12498782) that in this paper is shown to indirectly interact with presynaptic neurexin (Fig.7) to induce presynaptic differentiation (Fig.6). |
| Evidence tracking, Biological System: | Intact tissue Cultured neurons Non-neuronal tissue |
| Evidence tracking, Protein Targeting: | RNAi / shRNA Over-expression |
| Evidence tracking, Experiment Assay: | Confocal Whole-cell patch clamp |
| Annotator(s): | Pim van Nierop (ORCID:0000-0003-0593-3443) Guus Smit (ORCID:0000-0002-2286-1587) Matthijs Verhage (ORCID:0000-0002-2514-0216) |
| Lab: | Department of Functional Genomics, Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands |
| Additional literature: | Equivalent findings. @ PMID:24094106 |
| SynGO annotation ID: | 2821 |
| Dataset release (version): | 20231201 |
| View annotation as GO-CAM model: |  |