A Phosphate Transporter Also Hauls Glutamate

Abstract only One of the most important neurotransmitters, glutamate, has long held a secret from the research community -- the identity of its transporter into synaptic vesicles. Bellochio et al . (see the news story by Helmuth) now report that a protein previously thought to play a role in transporting inorganic phosphate across the plasma membrane, the brain-specific Na + -dependent inorganic phosphate transporter (BNPI), also acts as the glutamate transporter. Now bearing a second moniker, the vesicular glutamate transporter (VGLUT1), its role may be a function of its environment. The authors suggest that at the plasma membrane, it may function as BNPI, whereas in synaptic vesicles it functions as VGLUT1. Bellocchio, E.E., Reimer, R.J., Fremeau, R.T. Jr., and Edwards, R.H. (2000) Uptake of glutamate into synaptic vesicles by an inorganic phosphate transporter. Science 289 : 957-960. [Abstract] [Full Text] Helmuth, L. (2000) Long-sought protein packages glutamate. Science 289 : 847-849. [Abstract] [Full Text]