| Annotated protein: | Homer protein homolog 1 (Homer-1) (VASP/Ena-related gene up-regulated during seizure and LTP 1) (Vesl-1). Gene symbol: HOMER1. Taxonomy: Mus musculus (Mouse). Uniprot ID: Q9Z2Y3-5 |
| antibody wiki: | |
| SynGO gene info: | SynGO data @ HOMER1 |
| Ontology domain: | Biological Process |
| SynGO term: | regulation of postsynaptic neurotransmitter receptor activity (GO:0098962) |
| Synapse type(s): | cerebellum, glutamatergic |
| Annotated paper: | Ango F, et al. "Agonist-independent activation of metabotropic glutamate receptors by the intracellular protein Homer" Nature. 2001 Jun 21;411(6840):962-5 PMID:11418862 |
| Figure(s): | Figure 4 |
| Annotation description: | Homer1a is a short Homer1 isoform, upregulated in response to neuronal activity. Acts as an endogenous dominant-negative isoform, that disrupts binding of the constitutively expressed longer Homer isoforms to mGluR1/5 and thereby regulates mGluR activity. This PMID demonstrates that Homer1a competes with the interaction between long Homer isoforms and mGluR1a and thereby activates mGluR1a in the absence of agonist. 9/3/2017 Pim - Fig.1: KD of Homer3 (H3) activates mGluR1a signaling (using blockers and activatorrs or mGluRs to determine mGluR-involvement , and measured with BK channel as a funcional readout). This can be interpreted that Homer3 is a negative regulator of mGluRs --> term: [negative regulation of ...] [G-protein coupled glutamate receptor signaling pathway(GO:0007216)] term not existing. - Fig.4: As Fig.4, but now up-regulation of endogenous H1a (via NMDA and kainate stimulation) and overexpression of endogenous H1a is shown to activate mGluR-signaling --> term: [postive regulation of ...] [G-protein coupled glutamate receptor signaling pathway(GO:0007216)] term not existing. The relevance of these phenomena for synapses is suggested by PMID:10464340 by the same authors that show that "mGluR1α immunolabeling is concentrated in the endoplasmic reticulum in Purkinje cell bodies and in perisynaptic areas of parallel fiber synapses " --> Fig.7. |
| Evidence tracking, Biological System: | Cultured neurons |
| Evidence tracking, Protein Targeting: | Over-expression |
| Evidence tracking, Experiment Assay: | Whole-cell patch clamp IP + WB/MSMS |
| Annotator(s): | Harold MacGillavry (ORCID:0000-0002-6153-3586) Casper Hoogenraad (ORCID:0000-0002-2666-0758) |
| Lab: | Department of Biology, Faculty of Science, Utrecht University, 3584 CH Utrecht, The Netherlands |
| Additional literature: | This ref by the same authors of the primary annotated paper supports that the phenomena of mGluR1a signaling in the studied cerebellar neurons occur at synapses, rather that at non-synaptic sites. @ PMID:10464340 |
| SynGO annotation ID: | 238 |
| Dataset release (version): | 20231201 |
| View annotation as GO-CAM model: |  |