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Structural insights into how vacuolar sorting receptors recognize the sorting determinants of seed storage proteins

In Arabidopsis, vacuolar sorting receptor isoform 1 (VSR1) sorts 12S globulins to the protein storage vacuoles during seed development. Vacuolar sorting is mediated by specific protein–protein interactions between VSR1 and the vacuolar sorting determinant located at the C terminus (ctVSD) on the car...

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Autores principales: Tsao, Hsi-En, Lui, Shu Nga, Lo, Anthony Hiu-Fung, Chen, Shuai, Wong, Hiu Yan, Wong, Chi-Kin, Jiang, Liwen, Wong, Kam-Bo
Formato: Online Artículo Texto
Lenguaje:English
Publicado: National Academy of Sciences 2021
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8740768/
https://www.ncbi.nlm.nih.gov/pubmed/34983843
http://dx.doi.org/10.1073/pnas.2111281119
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author Tsao, Hsi-En
Lui, Shu Nga
Lo, Anthony Hiu-Fung
Chen, Shuai
Wong, Hiu Yan
Wong, Chi-Kin
Jiang, Liwen
Wong, Kam-Bo
author_facet Tsao, Hsi-En
Lui, Shu Nga
Lo, Anthony Hiu-Fung
Chen, Shuai
Wong, Hiu Yan
Wong, Chi-Kin
Jiang, Liwen
Wong, Kam-Bo
author_sort Tsao, Hsi-En
collection PubMed
description In Arabidopsis, vacuolar sorting receptor isoform 1 (VSR1) sorts 12S globulins to the protein storage vacuoles during seed development. Vacuolar sorting is mediated by specific protein–protein interactions between VSR1 and the vacuolar sorting determinant located at the C terminus (ctVSD) on the cargo proteins. Here, we determined the crystal structure of the protease-associated domain of VSR1 (VSR1-PA) in complex with the C-terminal pentapeptide ((468)RVAAA(472)) of cruciferin 1, an isoform of 12S globulins. The (468)RVA(470) motif forms a parallel β-sheet with the switch III residues ((127)TMD(129)) of VSR1-PA, and the (471)AA(472) motif docks to a cradle formed by the cargo-binding loop ((95)RGDCYF(100)), making a hydrophobic interaction with Tyr99. The C-terminal carboxyl group of the ctVSD is recognized by forming salt bridges with Arg95. The C-terminal sequences of cruciferin 1 and vicilin-like storage protein 22 were sufficient to redirect the secretory red fluorescent protein (spRFP) to the vacuoles in Arabidopsis protoplasts. Adding a proline residue to the C terminus of the ctVSD and R95M substitution of VSR1 disrupted receptor–cargo interactions in vitro and led to increased secretion of spRFP in Arabidopsis protoplasts. How VSR1-PA recognizes ctVSDs of other storage proteins was modeled. The last three residues of ctVSD prefer hydrophobic residues because they form a hydrophobic cluster with Tyr99 of VSR1-PA. Due to charge–charge interactions, conserved acidic residues, Asp129 and Glu132, around the cargo-binding site should prefer basic residues over acidic ones in the ctVSD. The structural insights gained may be useful in targeting recombinant proteins to the protein storage vacuoles in seeds.
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spelling pubmed-87407682022-06-30 Structural insights into how vacuolar sorting receptors recognize the sorting determinants of seed storage proteins Tsao, Hsi-En Lui, Shu Nga Lo, Anthony Hiu-Fung Chen, Shuai Wong, Hiu Yan Wong, Chi-Kin Jiang, Liwen Wong, Kam-Bo Proc Natl Acad Sci U S A Biological Sciences In Arabidopsis, vacuolar sorting receptor isoform 1 (VSR1) sorts 12S globulins to the protein storage vacuoles during seed development. Vacuolar sorting is mediated by specific protein–protein interactions between VSR1 and the vacuolar sorting determinant located at the C terminus (ctVSD) on the cargo proteins. Here, we determined the crystal structure of the protease-associated domain of VSR1 (VSR1-PA) in complex with the C-terminal pentapeptide ((468)RVAAA(472)) of cruciferin 1, an isoform of 12S globulins. The (468)RVA(470) motif forms a parallel β-sheet with the switch III residues ((127)TMD(129)) of VSR1-PA, and the (471)AA(472) motif docks to a cradle formed by the cargo-binding loop ((95)RGDCYF(100)), making a hydrophobic interaction with Tyr99. The C-terminal carboxyl group of the ctVSD is recognized by forming salt bridges with Arg95. The C-terminal sequences of cruciferin 1 and vicilin-like storage protein 22 were sufficient to redirect the secretory red fluorescent protein (spRFP) to the vacuoles in Arabidopsis protoplasts. Adding a proline residue to the C terminus of the ctVSD and R95M substitution of VSR1 disrupted receptor–cargo interactions in vitro and led to increased secretion of spRFP in Arabidopsis protoplasts. How VSR1-PA recognizes ctVSDs of other storage proteins was modeled. The last three residues of ctVSD prefer hydrophobic residues because they form a hydrophobic cluster with Tyr99 of VSR1-PA. Due to charge–charge interactions, conserved acidic residues, Asp129 and Glu132, around the cargo-binding site should prefer basic residues over acidic ones in the ctVSD. The structural insights gained may be useful in targeting recombinant proteins to the protein storage vacuoles in seeds. National Academy of Sciences 2021-12-30 2022-01-04 /pmc/articles/PMC8740768/ /pubmed/34983843 http://dx.doi.org/10.1073/pnas.2111281119 Text en Copyright © 2021 the Author(s). Published by PNAS. https://creativecommons.org/licenses/by-nc-nd/4.0/This article is distributed under Creative Commons Attribution-NonCommercial-NoDerivatives License 4.0 (CC BY-NC-ND) (https://creativecommons.org/licenses/by-nc-nd/4.0/) .
spellingShingle Biological Sciences
Tsao, Hsi-En
Lui, Shu Nga
Lo, Anthony Hiu-Fung
Chen, Shuai
Wong, Hiu Yan
Wong, Chi-Kin
Jiang, Liwen
Wong, Kam-Bo
Structural insights into how vacuolar sorting receptors recognize the sorting determinants of seed storage proteins
title Structural insights into how vacuolar sorting receptors recognize the sorting determinants of seed storage proteins
title_full Structural insights into how vacuolar sorting receptors recognize the sorting determinants of seed storage proteins
title_fullStr Structural insights into how vacuolar sorting receptors recognize the sorting determinants of seed storage proteins
title_full_unstemmed Structural insights into how vacuolar sorting receptors recognize the sorting determinants of seed storage proteins
title_short Structural insights into how vacuolar sorting receptors recognize the sorting determinants of seed storage proteins
title_sort structural insights into how vacuolar sorting receptors recognize the sorting determinants of seed storage proteins
topic Biological Sciences
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8740768/
https://www.ncbi.nlm.nih.gov/pubmed/34983843
http://dx.doi.org/10.1073/pnas.2111281119
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