Uptake of glutamate into synaptic vesicles by an inorganic phosphate transporter

Previous work has identified two families of proteins that transport classi cal neurotransmitters into synaptic vesicles, but the protein responsible f or vesicular transport of the principal excitatory transmitter glutamate ha s remained unknown. We demonstrate that a protein that is unrelated to any known neurotransmitter transporters and that was previously suggested to me diate the Na+-dependent uptake of inorganic phosphate across the plasma mem brane transports glutamate into synaptic vesicles. In addition, we show tha t this vesicular glutamate transporter, VGLUT1, exhibits a conductance for chloride that is blocked by glutamate.