Do Amino Acid Antiporters Have Asymmetric Substrate Specificity?
Amino acid antiporters mediate the 1:1 exchange of groups of amino acids. Whether substrate specificity can be different for the inward and outward facing conformation has not been investigated systematically, although examples of asymmetric transport have been reported. Here we used LC–MS to detect...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-02-01
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| Series: | Biomolecules |
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| Online Access: | https://www.mdpi.com/2218-273X/13/2/301 |
| _version_ | 1797622132567441408 |
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| author | Gregory Gauthier-Coles Stephen J. Fairweather Angelika Bröer Stefan Bröer |
| author_facet | Gregory Gauthier-Coles Stephen J. Fairweather Angelika Bröer Stefan Bröer |
| author_sort | Gregory Gauthier-Coles |
| collection | DOAJ |
| description | Amino acid antiporters mediate the 1:1 exchange of groups of amino acids. Whether substrate specificity can be different for the inward and outward facing conformation has not been investigated systematically, although examples of asymmetric transport have been reported. Here we used LC–MS to detect the movement of <sup>12</sup>C- and <sup>13</sup>C-labelled amino acid mixtures across the plasma membrane of <i>Xenopus laevis</i> oocytes expressing a variety of amino acid antiporters. Differences of substrate specificity between transporter paralogs were readily observed using this method. Our results suggest that antiporters are largely symmetric, equalizing the pools of their substrate amino acids. Exceptions are the antiporters y<sup>+</sup>LAT1 and y<sup>+</sup>LAT2 where neutral amino acids are co-transported with Na<sup>+</sup> ions, favouring their import. For the antiporters ASCT1 and ASCT2 glycine acted as a selective influx substrate, while proline was a selective influx substrate of ASCT1. These data show that antiporters can display non-canonical modes of transport. |
| first_indexed | 2024-03-11T09:05:59Z |
| format | Article |
| id | doaj.art-74e5a6aa94fd491f93eac758699d657d |
| institution | Directory Open Access Journal |
| issn | 2218-273X |
| language | English |
| last_indexed | 2024-03-11T09:05:59Z |
| publishDate | 2023-02-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Biomolecules |
| spelling | doaj.art-74e5a6aa94fd491f93eac758699d657d2023-11-16T19:23:14ZengMDPI AGBiomolecules2218-273X2023-02-0113230110.3390/biom13020301Do Amino Acid Antiporters Have Asymmetric Substrate Specificity?Gregory Gauthier-Coles0Stephen J. Fairweather1Angelika Bröer2Stefan Bröer3Research School of Biology, Australian National University, Canberra, ACT 0200, AustraliaResearch School of Biology, Australian National University, Canberra, ACT 0200, AustraliaResearch School of Biology, Australian National University, Canberra, ACT 0200, AustraliaResearch School of Biology, Australian National University, Canberra, ACT 0200, AustraliaAmino acid antiporters mediate the 1:1 exchange of groups of amino acids. Whether substrate specificity can be different for the inward and outward facing conformation has not been investigated systematically, although examples of asymmetric transport have been reported. Here we used LC–MS to detect the movement of <sup>12</sup>C- and <sup>13</sup>C-labelled amino acid mixtures across the plasma membrane of <i>Xenopus laevis</i> oocytes expressing a variety of amino acid antiporters. Differences of substrate specificity between transporter paralogs were readily observed using this method. Our results suggest that antiporters are largely symmetric, equalizing the pools of their substrate amino acids. Exceptions are the antiporters y<sup>+</sup>LAT1 and y<sup>+</sup>LAT2 where neutral amino acids are co-transported with Na<sup>+</sup> ions, favouring their import. For the antiporters ASCT1 and ASCT2 glycine acted as a selective influx substrate, while proline was a selective influx substrate of ASCT1. These data show that antiporters can display non-canonical modes of transport.https://www.mdpi.com/2218-273X/13/2/301LAT1LAT2y<sup>+</sup>LAT1y<sup>+</sup>LAT2asc-1ASCT1 |
| spellingShingle | Gregory Gauthier-Coles Stephen J. Fairweather Angelika Bröer Stefan Bröer Do Amino Acid Antiporters Have Asymmetric Substrate Specificity? Biomolecules LAT1 LAT2 y<sup>+</sup>LAT1 y<sup>+</sup>LAT2 asc-1 ASCT1 |
| title | Do Amino Acid Antiporters Have Asymmetric Substrate Specificity? |
| title_full | Do Amino Acid Antiporters Have Asymmetric Substrate Specificity? |
| title_fullStr | Do Amino Acid Antiporters Have Asymmetric Substrate Specificity? |
| title_full_unstemmed | Do Amino Acid Antiporters Have Asymmetric Substrate Specificity? |
| title_short | Do Amino Acid Antiporters Have Asymmetric Substrate Specificity? |
| title_sort | do amino acid antiporters have asymmetric substrate specificity |
| topic | LAT1 LAT2 y<sup>+</sup>LAT1 y<sup>+</sup>LAT2 asc-1 ASCT1 |
| url | https://www.mdpi.com/2218-273X/13/2/301 |
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