Enzymes
| UniProtKB help_outline | 644 proteins |
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- Name help_outline L-threonine Identifier CHEBI:57926 Charge 0 Formula C4H9NO3 InChIKeyhelp_outline AYFVYJQAPQTCCC-GBXIJSLDSA-N SMILEShelp_outline C[C@@H](O)[C@H]([NH3+])C([O-])=O 2D coordinates Mol file for the small molecule Search links Involved in 32 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline L-glutamine Identifier CHEBI:58359 Charge 0 Formula C5H10N2O3 InChIKeyhelp_outline ZDXPYRJPNDTMRX-VKHMYHEASA-N SMILEShelp_outline NC(=O)CC[C@H]([NH3+])C([O-])=O 2D coordinates Mol file for the small molecule Search links Involved in 77 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline Na+ Identifier CHEBI:29101 (CAS: 17341-25-2) help_outline Charge 1 Formula Na InChIKeyhelp_outline FKNQFGJONOIPTF-UHFFFAOYSA-N SMILEShelp_outline [Na+] 2D coordinates Mol file for the small molecule Search links Involved in 259 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
Cross-references
| RHEA:70863 | RHEA:70864 | RHEA:70865 | RHEA:70866 | |
|---|---|---|---|---|
| Reaction direction help_outline | undefined | left-to-right | right-to-left | bidirectional |
| UniProtKB help_outline |
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Publications
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Cysteine is not a substrate but a specific modulator of human ASCT2 (SLC1A5) transporter.
Scalise M., Pochini L., Pingitore P., Hedfalk K., Indiveri C.
The Alanine Serine Cysteine Transporter 2 (ASCT2) is involved in balancing the intracellular amino acid pool. This function is allowed by the antiport mechanism and the asymmetric specificity towards different neutral amino acids, distinctive of this transporter. In the present work, the interacti ... >> More
The Alanine Serine Cysteine Transporter 2 (ASCT2) is involved in balancing the intracellular amino acid pool. This function is allowed by the antiport mechanism and the asymmetric specificity towards different neutral amino acids, distinctive of this transporter. In the present work, the interaction of the putative substrate Cys with the human ASCT2 has been studied using the recombinant hASCT2 over-produced in Pichia pastoris and the native ASCT2 extracted from HeLa in both proteoliposomes and intact cells. It was found that Cys is a potent competitive inhibitor of hASCT2 but is not a substrate. Moreover, Cys binding to a second site, different from that of substrate, triggers a protein-mediated unidirectional Gln efflux. << Less
FEBS Lett. 589:3617-3623(2015) [PubMed] [EuropePMC]
This publication is cited by 1 other entry.
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Large scale production of the active human ASCT2 (SLC1A5) transporter in Pichia pastoris--functional and kinetic asymmetry revealed in proteoliposomes.
Pingitore P., Pochini L., Scalise M., Galluccio M., Hedfalk K., Indiveri C.
The human glutamine/neutral amino acid transporter ASCT2 (hASCT2) was over-expressed in Pichia pastoris and purified by Ni(2+)-chelating and gel filtration chromatography. The purified protein was reconstituted in liposomes by detergent removal with a batch-wise procedure. Time dependent [(3)H]glu ... >> More
The human glutamine/neutral amino acid transporter ASCT2 (hASCT2) was over-expressed in Pichia pastoris and purified by Ni(2+)-chelating and gel filtration chromatography. The purified protein was reconstituted in liposomes by detergent removal with a batch-wise procedure. Time dependent [(3)H]glutamine/glutamine antiport was measured in proteoliposomes which was active only in the presence of external Na(+). Internal Na(+) slightly stimulated the antiport. Optimal activity was found at pH7.0. A substantial inhibition of the transport was observed by Cys, Thr, Ser, Ala, Asn and Met (≥70%) and by mercurials and methanethiosulfonates (≥80%). Heterologous antiport of [(3)H]glutamine with other neutral amino acids was also studied. The transporter showed asymmetric specificity for amino acids: Ala, Cys, Val, Met were only inwardly transported, while Gln, Ser, Asn, and Thr were transported bi-directionally. From kinetic analysis of [(3)H]glutamine/glutamine antiport Km values of 0.097 and 1.8mM were measured on the external and internal sides of proteoliposomes, respectively. The Km for Na(+) on the external side was 32mM. The homology structural model of the hASCT2 protein was built using the GltPh of Pyrococcus horikoshii as template. Cys395 was the only Cys residue externally exposed, thus being the potential target of SH reagents inhibition and, hence, potentially involved in the transport mechanism. << Less
Biochim. Biophys. Acta 1828:2238-2246(2013) [PubMed] [EuropePMC]
This publication is cited by 7 other entries.