The last two transmembrane helices in the APC-type FurE transporter act as an intramolecular chaperone essential for concentrative ER-exit
FurE is a H+ symporter specific for the cellular uptake of uric acid, allantoin, uracil, and toxic nucleobase analogues in the fungus Aspergillus nidulans. Being member of the NCS1 protein family, FurE is structurally relat-ed to the APC-superfamily of transporters. APC-type transporters are charac-...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Shared Science Publishers OG
2024-01-01
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| Series: | Microbial Cell |
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| Online Access: | http://microbialcell.com/researcharticles/2024a-pyrris-microbial-cell/ |
| _version_ | 1797362692032299008 |
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| author | Yiannis Pyrris Georgia F. Papadaki Emmanuel Mikros George Diallinas |
| author_facet | Yiannis Pyrris Georgia F. Papadaki Emmanuel Mikros George Diallinas |
| author_sort | Yiannis Pyrris |
| collection | DOAJ |
| description | FurE is a H+ symporter specific for the cellular uptake of uric acid, allantoin, uracil, and toxic nucleobase analogues in the fungus Aspergillus nidulans. Being member of the NCS1 protein family, FurE is structurally relat-ed to the APC-superfamily of transporters. APC-type transporters are charac-terised by a 5+5 inverted repeat fold made of ten transmembrane segments (TMS1-10) and function through the rocking-bundle mechanism. Most APC-type transporters possess two extra C-terminal TMS segments (TMS11-12), the function of which remains elusive. Here we present a systematic muta-tional analysis of TMS11-12 of FurE and show that two specific aromatic resi-dues in TMS12, Trp473 and Tyr484, are essential for ER-exit and trafficking to the plasma membrane (PM). Molecular modeling shows that Trp473 and Tyr484 might be essential through dynamic interactions with residues in TMS2 (Leu91), TMS3 (Phe111), TMS10 (Val404, Asp406) and other aromatic residues in TMS12. Genetic analysis confirms the essential role of Phe111, Asp406 and TMS12 aromatic residues in FurE ER-exit. We further show that co-expression of FurE-Y484F or FurE-W473A with wild-type FurE leads to a dominant negative phenotype, compatible with the concept that FurE mole-cules oligomerize or partition in specific microdomains to achieve concentra-tive ER-exit and traffic to the PM. Importantly, truncated FurE versions lacking TMS11-12 are unable to reproduce a negative effect on the trafficking of co-expressed wild-type FurE. Overall, we show that TMS11-12 acts as an intra-molecular chaperone for proper FurE folding, which seems to provide a struc-tural code for FurE partitioning in ER-exit sites. |
| first_indexed | 2024-03-08T16:10:08Z |
| format | Article |
| id | doaj.art-207939987211495eac00c8e0b52db847 |
| institution | Directory Open Access Journal |
| issn | 2311-2638 |
| language | English |
| last_indexed | 2024-03-08T16:10:08Z |
| publishDate | 2024-01-01 |
| publisher | Shared Science Publishers OG |
| record_format | Article |
| series | Microbial Cell |
| spelling | doaj.art-207939987211495eac00c8e0b52db8472024-01-07T18:27:11ZengShared Science Publishers OGMicrobial Cell2311-26382024-01-011111510.15698/mic2024.01.811The last two transmembrane helices in the APC-type FurE transporter act as an intramolecular chaperone essential for concentrative ER-exitYiannis Pyrris0Georgia F. Papadaki1Emmanuel Mikros2George Diallinas3Department of Biology, National and Kapodistrian University of Athens, Panepistimioupolis, Athens, 15784, Greece.Department of Biology, National and Kapodistrian University of Athens, Panepistimioupolis, Athens, 15784, Greece.Department of Pharmacy, National and Kapodistrian University of Athens, Panepistimioupolis, Athens, 15771, Greece.Department of Biology, National and Kapodistrian University of Athens, Panepistimioupolis, Athens, 15784, Greece.FurE is a H+ symporter specific for the cellular uptake of uric acid, allantoin, uracil, and toxic nucleobase analogues in the fungus Aspergillus nidulans. Being member of the NCS1 protein family, FurE is structurally relat-ed to the APC-superfamily of transporters. APC-type transporters are charac-terised by a 5+5 inverted repeat fold made of ten transmembrane segments (TMS1-10) and function through the rocking-bundle mechanism. Most APC-type transporters possess two extra C-terminal TMS segments (TMS11-12), the function of which remains elusive. Here we present a systematic muta-tional analysis of TMS11-12 of FurE and show that two specific aromatic resi-dues in TMS12, Trp473 and Tyr484, are essential for ER-exit and trafficking to the plasma membrane (PM). Molecular modeling shows that Trp473 and Tyr484 might be essential through dynamic interactions with residues in TMS2 (Leu91), TMS3 (Phe111), TMS10 (Val404, Asp406) and other aromatic residues in TMS12. Genetic analysis confirms the essential role of Phe111, Asp406 and TMS12 aromatic residues in FurE ER-exit. We further show that co-expression of FurE-Y484F or FurE-W473A with wild-type FurE leads to a dominant negative phenotype, compatible with the concept that FurE mole-cules oligomerize or partition in specific microdomains to achieve concentra-tive ER-exit and traffic to the PM. Importantly, truncated FurE versions lacking TMS11-12 are unable to reproduce a negative effect on the trafficking of co-expressed wild-type FurE. Overall, we show that TMS11-12 acts as an intra-molecular chaperone for proper FurE folding, which seems to provide a struc-tural code for FurE partitioning in ER-exit sites.http://microbialcell.com/researcharticles/2024a-pyrris-microbial-cell/aspergillus nidulanstransportermembrane trafficncs1sortinger exit |
| spellingShingle | Yiannis Pyrris Georgia F. Papadaki Emmanuel Mikros George Diallinas The last two transmembrane helices in the APC-type FurE transporter act as an intramolecular chaperone essential for concentrative ER-exit Microbial Cell aspergillus nidulans transporter membrane traffic ncs1 sorting er exit |
| title | The last two transmembrane helices in the APC-type FurE transporter act as an intramolecular chaperone essential for concentrative ER-exit |
| title_full | The last two transmembrane helices in the APC-type FurE transporter act as an intramolecular chaperone essential for concentrative ER-exit |
| title_fullStr | The last two transmembrane helices in the APC-type FurE transporter act as an intramolecular chaperone essential for concentrative ER-exit |
| title_full_unstemmed | The last two transmembrane helices in the APC-type FurE transporter act as an intramolecular chaperone essential for concentrative ER-exit |
| title_short | The last two transmembrane helices in the APC-type FurE transporter act as an intramolecular chaperone essential for concentrative ER-exit |
| title_sort | last two transmembrane helices in the apc type fure transporter act as an intramolecular chaperone essential for concentrative er exit |
| topic | aspergillus nidulans transporter membrane traffic ncs1 sorting er exit |
| url | http://microbialcell.com/researcharticles/2024a-pyrris-microbial-cell/ |
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