General Description
Vesicular glutamate transporter 3 (UniProt Q7TSF2; also known as Solute carrier family 17 member 8, VGluT3) is encoded by the Slc17a8 (also known as Vglut3) gene (Gene ID 266767) in rat species. Vesicular glutamate transporters (VGluTs) are proton-dependent carriers responsible for the upload of the major excitatory neurotransmitter glutamate into synaptic vesicles within presynaptic terminals to allow later regulated release at the synaptic cleft. Studies conducted in mice show that VGluT1 and VGluT2 are essential for vital functions, while Vglut3-knockout mice have a normal life expectancy despite being deaf and developing anxiety and discrete basal locomotor phenotypes. VGluT1- and VGluT2-expressing neurons represent the bulk of canonical glutamatergic neurons in the brain, with VgluT1 representing the major subtype and accounting for approximately 80% of total vesicular transport of glutamate in the brain. In contrast, VgluT3 is found in discrete population of non-glutamatergic neurons using other transmitters than glutamate, such as cholinergic interneurons in the dorsal and ventral striatum, subpopulations of GABAergic basket cells in the cortex and hippocampus, and serotoninergic neurons, where it is involved in more subtle modulation of local transmission. Rat VGluT3 is a 12-transmembrane (a.a. 77-97, 131-151, 154-174, 183-203, 222-242, 250-270, 315-335, 354-374, 391-411, 414-434, 448-468, 482-502) protein with 7 cytoplasmic and 6 vacuolar domains, having both its N- and C-terminal tails (a.a. 1-76 and 503-585) exposed at the cytoplasmic side.
