Abstract
The sodium-coupled neutral amino acid transporters (SNAT) of the SLC38 gene family resemble the classically-described System A and System N transport activities in terms of their functional properties and patterns of regulation. Transport of small, aliphatic amino acids by System A subtypes (SNAT1, SNAT2, and SNAT4) is rheogenic and pH sensitive. The System N subtypes SNAT3 and SNAT5 also countertransport H+, which may be key to their operation in reverse, and have narrower substrate profiles than do the System A subtypes. Glutamine emerges as a favored substrate throughout the family, except for SNAT4. The SLC38 transporters undoubtedly play many physiological roles including the transfer of glutamine from astrocyte to neuron in the CNS, ammonia detoxification and gluconeogenesis in the liver, and the renal response to acidosis. Probing their regulation has revealed additional roles, and recent work has considered SLC38 transporters as therapeutic targets in neoplasia.
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Notes
We propose here that the transporters of the SLC38 gene family be renamed SNAT1–6, numbered in line with the corresponding gene symbols (see Table 1). We suggest that SNAT should stand for "Sodium-coupled Neutral Amino acid Transporter" (and also recall the classic transport activities, i.e., "System N/A Transporter"). An overwhelming majority of the investigators consulted support the revised nomenclature. Those polled included S. Bröer, F.A. Chaudhry, F. Conti, R.H. Edwards, V. Ganapathy, M.A. Hediger, H.S. Hundal, J.X. Jiang, M.S. Kilberg, M. Matteoli, J.C. Matthews, H. Varoqui, and E. Weihe.
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Mackenzie, B., Erickson, J.D. Sodium-coupled neutral amino acid (System N/A) transporters of the SLC38 gene family. Pflugers Arch - Eur J Physiol 447, 784–795 (2004). https://doi.org/10.1007/s00424-003-1117-9
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DOI: https://doi.org/10.1007/s00424-003-1117-9