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SLC32 vesicular inhibitory amino acid transporter C

Unless otherwise stated all data on this page refer to the human proteins. Gene information is provided for human (Hs), mouse (Mm) and rat (Rn).


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The vesicular inhibitory amino acid transporter, VIAAT (also termed the vesicular GABA transporter VGAT), which is the sole representative of the SLC32 family, transports GABA, or glycine, into synaptic vesicles [2-3], and is a member of the structurally-defined amino acid-polyamine-organocation/APC clan composed of SLC32, SLC36 and SLC38 transporter families (see [8]). VIAAT was originally suggested to be composed of 10 TM segments with cytoplasmic N- and C-termini [6]. However, an alternative 9TM structure with the N terminus facing the cytoplasm and the C terminus residing in the synaptic vesicle lumen has subsequently been reported [5]. VIAAT acts as an antiporter for inhibitory amino acids and protons. The accumulation of GABA and glycine within vesicles is driven by both the chemical (ΔpH) and electrical (Δψ) components of the proton electrochemical gradient (ΔµH+) established by a vacuolar H+-ATPase [6]. However, one study, [4], presented evidence that VIAAT is instead a Cl-/GABA co-transporter. VIAAT co-exists with VGLUT1 (SLC17A7), or VGLUT2 (SLC17A6), in the synaptic vesicles of selected nerve terminals [1,10]. VIAAT knock out mice die between embryonic day 18.5 and birth [9]. In cultures of spinal cord neurones established from earlier embryos, the co-release of of GABA and glycine from synaptic vesicles is drastically reduced, providing direct evidence for the role of VIAAT in the sequestration of both transmitters [7,9].


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VIAAT (Vesicular inhibitory amino acid transporter / SLC32A1) C Show summary »

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How to cite this family page

Database page citation:

SLC32 vesicular inhibitory amino acid transporter. Accessed on 02/10/2023. IUPHAR/BPS Guide to PHARMACOLOGY,

Concise Guide to PHARMACOLOGY citation:

Alexander SP, Kelly E, Mathie A, Peters JA, Veale EL et al. (2021) THE CONCISE GUIDE TO PHARMACOLOGY 2021/22: Transporters. Br J Pharmacol. 178 Suppl 1:S412-S513.