SLC17A7

The protein encoded by this gene is a vesicle-bound, sodium-dependent phosphate transporter that is specifically expressed in the neuron-rich regions of the brain. It is preferentially associated with the membranes of synaptic vesicles and functions in glutamate transport. The protein shares 82% identity with the differentiation-associated Na-dependent inorganic phosphate cotransporter and they appear to form a distinct class within the Na+/Pi cotransporter family.

Full Name

Solute Carrier Family 17 Member 7

Function

Multifunctional transporter that transports L-glutamate as well as multiple ions such as chloride, proton, potassium, sodium and phosphate (PubMed:10820226).
At the synaptic vesicle membrane, mainly functions as an uniporter which transports preferentially L-glutamate but also phosphate from the cytoplasm into synaptic vesicles at presynaptic nerve terminals of excitatory neural cells (By similarity).
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 (By similarity).
In addition, functions as a chloride channel that allows a chloride permeation through the synaptic vesicle membrane that affects the proton electrochemical gradient and promotes synaptic vesicles acidification (By similarity).
Moreover, may function as a K+/H+ antiport allowing to maintain the electrical gradient and to decrease chemical gradient and therefore sustain vesicular glutamate uptake (By similarity).
The vesicular K+/H+ antiport activity is electroneutral (By similarity).
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:10820226).
The symporter activity is driven by an inside negative membrane potential and is electrogenic (By similarity).
Is necessary for synaptic signaling of visual-evoked responses from photoreceptors (By similarity).

Biological Process

Biological Process anion transportManual Assertion Based On ExperimentIBA:GO_Central
Biological Process brain developmentIEA:Ensembl
Biological Process chloride transportISS:UniProtKB
Biological Process ion transportTAS:Reactome
Biological Process L-glutamate transmembrane transportISS:UniProtKB
Biological Process neural retina developmentIEA:Ensembl
Biological Process neurotransmitter loading into synaptic vesicleManual Assertion Based On ExperimentIBA:GO_Central
Biological Process neurotransmitter transportTAS:Reactome
Biological Process phosphate ion homeostasisIEA:Ensembl
Biological Process phosphate ion transportISS:UniProtKB
Biological Process potassium ion transportISS:UniProtKB
Biological Process regulation of synapse structure or activityManual Assertion Based On ExperimentIBA:GO_Central
Biological Process regulation of synaptic vesicle endocytosisIEA:Ensembl
Biological Process sodium-dependent phosphate transportISS:UniProtKB
Biological Process synaptic transmission, glutamatergicManual Assertion Based On ExperimentIBA:GO_Central

Cellular Location

Cytoplasmic vesicle, secretory vesicle, synaptic vesicle membrane
Cell membrane
Synapse, synaptosome

Topology

Cytoplasmic: 1-63
Helical: 64-84
Extracellular: 85-116
Helical: 117-137
Cytoplasmic: 138-140
Helical: 141-161
Extracellular: 162-169
Helical: 170-190
Cytoplasmic: 191-208
Helical: 209-229
Extracellular: 230-236
Helical: 237-257
Cytoplasmic: 258-302
Helical: 303-323
Extracellular: 324-341
Helical: 342-362
Cytoplasmic: 363-378
Helical: 379-399
Extracellular: 400-401
Helical: 402-422
Cytoplasmic: 423-435
Helical: 436-456
Extracellular: 457-469
Helical: 470-490
Cytoplasmic: 491-560