| Structural highlights
Function
[AAAT_HUMAN] Sodium-dependent amino acids transporter that has a broad substrate specificity, with a preference for zwitterionic amino acids. It accepts as substrates all neutral amino acids, including glutamine, asparagine, and branched-chain and aromatic amino acids, and excludes methylated, anionic, and cationic amino acids (PubMed:8702519). Through binding of the fusogenic protein syncytin-1/ERVW-1 may mediate trophoblasts syncytialization, the spontaneous fusion of their plasma membranes, an essential process in placental development (PubMed:10708449, PubMed:23492904).[1] [2] [3] (Microbial infection) Acts as a cell surface receptor for Feline endogenous virus RD114.[4] [5] (Microbial infection) Acts as a cell surface receptor for Baboon M7 endogenous virus.[6] (Microbial infection) Acts as a cell surface receptor for type D simian retroviruses.[7]
Publication Abstract from PubMed
The human Alanine Serine Cysteine Transporter 2 (ASCT2) is a neutral amino acid exchanger that belongs to the solute carrier family 1 (SLC1A). SLC1A structures have revealed an elevator-type mechanism, in which the substrate is translocated across the cell membrane by a large displacement of the transport domain, whereas a small movement of hairpin 2 (HP2) gates the extracellular access to the substrate-binding site. However, it has remained unclear how substrate binding and release is gated on the cytoplasmic side. Here, we present an inward-open structure of the human ASCT2, revealing a hitherto elusive SLC1A conformation. Strikingly, the same structural element (HP2) serves as a gate in the inward-facing as in the outward-facing state. The structures reveal that SLC1A transporters work as one-gate elevators. Unassigned densities near the gate and surrounding the scaffold domain, may represent potential allosteric binding sites, which could guide the design of lipidic-inhibitors for anticancer therapy.
A one-gate elevator mechanism for the human neutral amino acid transporter ASCT2.,Garaeva AA, Guskov A, Slotboom DJ, Paulino C Nat Commun. 2019 Jul 31;10(1):3427. doi: 10.1038/s41467-019-11363-x. PMID:31366933[8]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Blond JL, Lavillette D, Cheynet V, Bouton O, Oriol G, Chapel-Fernandes S, Mandrand B, Mallet F, Cosset FL. An envelope glycoprotein of the human endogenous retrovirus HERV-W is expressed in the human placenta and fuses cells expressing the type D mammalian retrovirus receptor. J Virol. 2000 Apr;74(7):3321-9. PMID:10708449
- ↑ Sugimoto J, Sugimoto M, Bernstein H, Jinno Y, Schust D. A novel human endogenous retroviral protein inhibits cell-cell fusion. Sci Rep. 2013;3:1462. doi: 10.1038/srep01462. PMID:23492904 doi:http://dx.doi.org/10.1038/srep01462
- ↑ Kekuda R, Prasad PD, Fei YJ, Torres-Zamorano V, Sinha S, Yang-Feng TL, Leibach FH, Ganapathy V. Cloning of the sodium-dependent, broad-scope, neutral amino acid transporter Bo from a human placental choriocarcinoma cell line. J Biol Chem. 1996 Aug 2;271(31):18657-61. PMID:8702519
- ↑ Rasko JE, Battini JL, Gottschalk RJ, Mazo I, Miller AD. The RD114/simian type D retrovirus receptor is a neutral amino acid transporter. Proc Natl Acad Sci U S A. 1999 Mar 2;96(5):2129-34. PMID:10051606
- ↑ Tailor CS, Nouri A, Zhao Y, Takeuchi Y, Kabat D. A sodium-dependent neutral-amino-acid transporter mediates infections of feline and baboon endogenous retroviruses and simian type D retroviruses. J Virol. 1999 May;73(5):4470-4. PMID:10196349
- ↑ Tailor CS, Nouri A, Zhao Y, Takeuchi Y, Kabat D. A sodium-dependent neutral-amino-acid transporter mediates infections of feline and baboon endogenous retroviruses and simian type D retroviruses. J Virol. 1999 May;73(5):4470-4. PMID:10196349
- ↑ Tailor CS, Nouri A, Zhao Y, Takeuchi Y, Kabat D. A sodium-dependent neutral-amino-acid transporter mediates infections of feline and baboon endogenous retroviruses and simian type D retroviruses. J Virol. 1999 May;73(5):4470-4. PMID:10196349
- ↑ Garaeva AA, Guskov A, Slotboom DJ, Paulino C. A one-gate elevator mechanism for the human neutral amino acid transporter ASCT2. Nat Commun. 2019 Jul 31;10(1):3427. doi: 10.1038/s41467-019-11363-x. PMID:31366933 doi:http://dx.doi.org/10.1038/s41467-019-11363-x
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