| First Author | Sakagami H | Year | 2008 |
| Journal | Neurosci Res | Volume | 60 |
| Issue | 2 | Pages | 199-212 |
| PubMed ID | 18164504 | Mgi Jnum | J:131067 |
| Mgi Id | MGI:3772760 | Doi | 10.1016/j.neures.2007.10.013 |
| Citation | Sakagami H, et al. (2008) IQ-ArfGEF/BRAG1 is a guanine nucleotide exchange factor for Arf6 that interacts with PSD-95 at postsynaptic density of excitatory synapses. Neurosci Res 60(2):199-212 |
| abstractText | ADP ribosylation factor 6 (Arf6) is a small GTPase that regulates dendritic differentiation possibly through the organization of actin cytoskeleton and membrane traffic. Here, we characterized IQ-ArfGEF/BRAG1, a guanine nucleotide exchange factor (GEF) for Arf6, in the mouse brain. In vivo Arf pull down assay demonstrated that IQ-ArfGEF/BRAG1 activated Arf6 more potently than Arf1. IQ-ArfGEF/BRAG1 mRNA was abundantly expressed in the brain with higher levels in forebrain structures and cerebellar granule cells. In hippocampal neurons, IQ-ArfGEF/BRAG1 mRNA was localized not only at neuronal cell bodies but also at dendritic processes, indicating its dendritic transport and localization. Immunoprecipitation and in vitro binding experiments revealed that IQ-ArfGEF/BRAG1 formed a protein complex with N-methyl-d-aspartate (NMDA)-type glutamate receptors through the interaction with a postsynaptic density (PSD) scaffold protein, PSD-95. Immunohistochemical analysis demonstrated that IQ-ArfGEF/BRAG1 was localized preferentially at the postsynaptic density of asymmetrical synapses on dendritic spines, but was lacking at GABAa receptor-carrying inhibitory synapses. Taken together, IQ-ArfGEF/BRAG1 forms a postsynaptic protein complex containing PSD-95 and NMDA receptors at excitatory synapses, where it may function as a GEF for Arf6. |
