The SLC17A7 (also known as VGLUT1) gene encodes the Vesicular Glutamate Transporter 1, a critical protein responsible for packaging glutamate into synaptic vesicles at excitatory nerve terminals. Located on chromosome 19q13.33, this gene is essential for glutamatergic neurotransmission in the mammalian brain. VGLUT1 is the principal vesicular glutamate transporter in the cerebral cortex, hippocampus, and cerebellar cortex, where it defines the identity and quantal output of the majority of excitatory synapses[1][2].
| SLC17A7 (VGLUT1) | |
|---|---|
| Gene Symbol | SLC17A7 |
| Alternative Names | VGLUT1, BNPI |
| Chromosomal Location | 19q13.33 |
| NCBI Gene ID | [57087](https://www.ncbi.nlm.nih.gov/gene/57087) |
| Ensembl ID | ENSG00000177508 |
| UniProt ID | [Q9P2U7](https://www.uniprot.org/uniprot/Q9P2U7) |
| Protein Name | Vesicular Glutamate Transporter 1 |
| Protein Length | 560 amino acids (~62 kDa) |
| Expression | Cortex, Hippocampus, Cerebellum |
The SLC17A7 gene spans approximately 17.5 kb and consists of 12 exons that encode a 560-amino acid protein. It belongs to the SLC17 family of anion transporters, which evolved from a prokaryotic phosphate transporter ancestor. The gene shows conserved synteny with other VGLUT genes (SLC17A6/VGLUT2 and SLC17A8/VGLUT3) throughout vertebrate evolution[3][4].
This complementarity suggests functional specialization: VGLUT1-bearing synapses favor reliable, low-probability transmission suited for cortical information processing, while VGLUT2 supports high-fidelity sensory relay from thalamus to cortex[5].
VGLUT1 is a multipass transmembrane protein with 12 predicted transmembrane domains. The protein operates as a proton-dependent symporter, using the energy from the vacuolar H+-ATPase (V-ATPase) proton gradient to concentrate glutamate inside synaptic vesicles[6].
VGLUT1 exhibits a highly specific expression pattern in the adult brain[10]:
VGLUT1 protein localizes specifically to glutamatergic synaptic vesicles in presynaptic terminals. Importantly, it is excluded from GABAergic and glycinergic terminals, making it a definitive marker for excitatory synapses[11][12].
Interestingly, recent studies have detected VGLUT1 in dendritic compartments, challenging the traditional view of exclusive axonal localization. This dendritic expression may support non-synaptic glutamate release or local signaling functions[marta2018].
VGLUT1 expression level directly controls excitatory synaptic strength:
VGLUT1's interaction with endophilin A1 via its C-terminal polyproline domain is critical for synaptic vesicle recycling[9:1]:
VGLUT1 loss is one of the earliest and most consistent synaptic biomarkers in Alzheimer's disease[14][15]:
In Parkinson's disease, corticostriatal VGLUT1-positive terminals show early dysfunction[liu2014]:
Paradoxically, while VGLUT1 loss underlies hypofunction in AD, its overexpression can cause excitotoxicity:
The expression of vesicular glutamate transporters defines two classes of excitatory synapse. Neuron. 2001. ↩︎
VGLUTs in glutamate neurotransmission. Curr Opin Neurobiol. 2004. ↩︎
The proton-coupled polymorphic glycoprotein of the synaptic vesicle is a vesicular glutamate transporter. J Biol Chem. 2000. ↩︎
Identification, molecular characterization, and distribution of a novel vesicular glutamate transporter from mouse brain. J Comp Neurol. 1998. ↩︎
Localizing vesicular glutamate transporters to synapses. Neuron. 2002. ↩︎
VGLUT1 functions as a glutamate/proton exchanger with chloride channel activity in hippocampal glutamatergic synapses. Nat Commun. 2017. ↩︎
Chloride dependence of vesicular glutamate transporters. Cell Mol Neurobiol. 2015. ↩︎
Presynaptic regulation of quantal size by the vesicular glutamate transporter VGLUT1. J Neurosci. 2005. ↩︎
Distinct endophilin interactions with VGLUT1 and VGLUT2 control synaptic vesicle recycling. Neuron. 2006. ↩︎ ↩︎
Differential expressions of vesicular glutamate transporters 1 and 2 in the mouse hippocampus. Neuroscience. 2011. ↩︎
Vesicular glutamate transporter 1 expression in the rat spinal cord. J Comp Neurol. 1999. ↩︎
VGLUT2-containing vesicles and synaptophysin in the adult mouse brain. Brain Res. 2009. ↩︎
Activity-dependent regulation of the VGLUT1asin the brain. J Physiol Paris. 2009. ↩︎
Loss of VGLUT1 and VGLUT2 in the prefrontal cortex is correlated with cognitive decline in Alzheimer disease. Neurobiol Aging. 2008. ↩︎
Down-regulation of glutamatergic terminals VGLUT1 driven by Abeta in Alzheimer's disease. Hippocampus. 2016. ↩︎