| 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
Human ASCT2 belongs to the SLC1 family of secondary transporters and is specific for the transport of small neutral amino acids. ASCT2 is upregulated in cancer cells and serves as the receptor for many retroviruses; hence, it has importance as a potential drug target. Here we used single-particle cryo-EM to determine a structure of the functional and unmodified human ASCT2 at 3.85-A resolution. ASCT2 forms a homotrimeric complex in which each subunit contains a transport and a scaffold domain. Prominent extracellular extensions on the scaffold domain form the predicted docking site for retroviruses. Relative to structures of other SLC1 members, ASCT2 is in the most extreme inward-oriented state, with the transport domain largely detached from the central scaffold domain on the cytoplasmic side. This domain detachment may be required for substrate binding and release on the intracellular side of the membrane.
Cryo-EM structure of the human neutral amino acid transporter ASCT2.,Garaeva AA, Oostergetel GT, Gati C, Guskov A, Paulino C, Slotboom DJ Nat Struct Mol Biol. 2018 Jun;25(6):515-521. doi: 10.1038/s41594-018-0076-y. Epub, 2018 Jun 5. PMID:29872227[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, Oostergetel GT, Gati C, Guskov A, Paulino C, Slotboom DJ. Cryo-EM structure of the human neutral amino acid transporter ASCT2. Nat Struct Mol Biol. 2018 Jun;25(6):515-521. doi: 10.1038/s41594-018-0076-y. Epub, 2018 Jun 5. PMID:29872227 doi:http://dx.doi.org/10.1038/s41594-018-0076-y
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