Vesicular glutamate transporter 2

UniProtKB accession:  Q9JI12

Grouped By:  Matching UniProtKB accession

UniProtKB description:  Multifunctional transporter that transports L-glutamate as well as multiple ions such as chloride, proton, potassium, sodium and phosphate (PubMed:18080752, PubMed:11551935, PubMed:11698619, PubMed:11502256, PubMed:29642010, PubMed:17046815, PubMed:32439795, PubMed:27133463, PubMed:25433636). At the synaptic vesicle membrane, mainly functions as a uniporter which transports preferentially L-glutamate but also, phosphate from the cytoplasm into synaptic vesicles at presynaptic nerve terminals of excitatory neural cells (PubMed:18080752, PubMed:11698619, PubMed:11551935, PubMed:11502256, PubMed:29642010, PubMed:17046815, PubMed:32439795, PubMed:27133463). The L-glutamate or phosphate uniporter activity is electrogenic and is driven by the proton electrochemical gradient, mainly by the electrical gradient established by the vacuolar H(+)-ATPase across the synaptic vesicle membrane (PubMed:11551935, PubMed:11698619, PubMed:11502256, PubMed:17046815, PubMed:32439795, PubMed:29642010). In addition, functions as a chloride channel that allows a chloride permeation through the synaptic vesicle membrane therefore affects the proton electrochemical gradient and promotes synaptic vesicles acidification (PubMed:27133463). Moreover, functions as a vesicular K(+)/H(+) antiport allowing to maintain the electrical gradient and to decrease chemical gradient and therefore sustain vesicular L-glutamate uptake (PubMed:25433636). The vesicular H(+)/H(+) antiport activity is electroneutral (PubMed:25433636). At the plasma membrane, following exocytosis, functions as a symporter of Na(+) and phosphate from the extracellular space to the cytoplasm allowing synaptic phosphate homeostasis regulation (PubMed:17046815, PubMed:29642010). The symporter activity is driven by an inside negative membrane potential and is electrogenic (PubMed:29642010, PubMed:17046815). Also involved in the regulation of retinal hyaloid vessel regression during postnatal development (By similarity). May also play a role in the endocrine L-glutamatergic system of other tissues such as pineal gland and pancreas (PubMed:11551935).