| Annotated protein: | Alpha-internexin (Alpha-Inx). Gene symbol: INA. Taxonomy: Rattus norvegicus (Rat). Uniprot ID: P23565 |
| antibody wiki: | |
| SynGO gene info: | SynGO data @ INA |
| Ontology domain: | Cellular Component |
| SynGO term: | postsynaptic density, intracellular component (GO:0099092) |
| Synapse type(s): | brain, glutamatergic cerebral cortex, glutamatergic |
| Annotated paper: | Suzuki T, et al. "Excitable membranes and synaptic transmission: postsynaptic mechanisms. Localization of alpha-internexin in the postsynaptic density of the rat brain" Brain Res. 1997 Aug 8;765(1):74-80 PMID:9310396 |
| Figure(s): | Fig 1,2,3,6 |
| Annotation description: | Alpha-internexin is found in PSD fractions prepared from the rat forebrain but also cerebral cortex, hippocampus and cerebellum. The protein is present different subcellular compartments but enriched in the PSD fraction. No immunoreactivity was found in the soluble fraction. Moreover, alpha-internexin is also found in the neurofilament enriched fraction together with together with other neurofilament subunits, which suggests its tight association with neurofilaments. Electro microscopy analysis of samples immunostained with the antibody and visualized with diaminobenzidine revealed alpha-internexin immunoreactiviy in dendrites, spines and PSD were strongly immunoreactive. Importantly, these samples were not post stained with uranyl acetate to prevent unspecificity in the electron density labeling. Not all PSDs were immunoreactive. Presynaptic terminals were not labelled. Authors suggest based in the EM data and the high enrichment in the PSD fractions that alpha-internexin is a PSD constituent in vivo that may help in the organization of the PSD and mention, based on unpublished observations, that plectin, a cross-linker of intermediate filaments is present in the PSD fraction. 13/6/2017 Pim - Authors speculate that intermediate filament localization to the PSD might represent a early developmental state in the formation of a postsynaptic specialization. |
| Evidence tracking, Biological System: | Intact tissue |
| Evidence tracking, Protein Targeting: | Antibody (detection) |
| Evidence tracking, Experiment Assay: | Electron Microscopy Western blot Biochemical fractionation (generic) |
| Annotator(s): | Maria Andres-Alonso (ORCID:0000-0002-1585-539X) Michael Kreutz (ORCID:0000-0003-0575-6950) |
| Lab: | RG Neuroplasticity, Leibniz Institute for Neurobiology, 39118 Magdeburg, Germany and Leibniz Group 'Dendritic Organelles and Synaptic Function', Center for Molecular Neurobiology, ZMNH, University MC, Hamburg-Eppendorf, Hamburg, 20251, Germany |
| Additional literature: | A 66-kDa protein is isolated from a crude intermediate filament proteins from adult rat optic nerve and spinal cord. Authors name this protein as alpha-internexin. This protein is reactive against an antibody anti intermediate filament antigen. Unlike NF68, the protein cannot polymerize into 10nm filaments and authors suggest that the protein does not constitute an independent filamentous system but an intermediate filament-binding protein which associated with filaments in vivo. In line with this, the binding of the protein with intermediate filaments approaches saturation. @ PMID:2413040 |
| SynGO annotation ID: | 3667 |
| Dataset release (version): | 20231201 |
| View annotation as GO-CAM model: |  |