High impact information on VGlut

• Consistent with the presence of empty vesicles, at dvglut mutant synapses synaptic vesicles are smaller, suggesting that vesicle filling and/or transporter level is an important determinant of vesicle size [1].
• At glutamatergic synapses, the vesicular glutamate transporter (VGLUT) fills vesicles with glutamate [1].
• In this issue of Neuron, a study by Daniels et al. using the Drosophila neuromuscular junction and mutations of the vesicular glutamate transporter suggests that one transporter may suffice to fill each vesicle [2].
• In situ hybridization experiments using antisense probes against the mRNAs of DVGLUT and neighboring genes confirm that OK371-Gal4 detects an enhancer of DVGLUT [3].
• As development proceeds, DVGLUT-positive particles are transported along motor axons and become concentrated at neuromuscular junctions (NMJs), where they colocalize with the synaptic vesicle marker synaptotagmin [3].

Anatomical context of VGlut

• Increasing the expression of DVGLUT in motoneurons leads to an increase in quantal size that is accompanied by an increase in synaptic vesicle volume [4].
• DVGLUT mRNA is expressed in glutamatergic motoneurons and a large number of interneurons in the Drosophila CNS [4].
• DVGLUT protein resides on synaptic vesicles and localizes to the presynaptic terminals of all known glutamatergic neuromuscular junctions as well as to synapses throughout the CNS neuropil [4].

Associations of VGlut with chemical compounds

• Increased expression of the Drosophila vesicular glutamate transporter leads to excess glutamate release and a compensatory decrease in quantal content [4].

References