Cargando…
Plastid chaperone HSP90C guides precursor proteins to the SEC translocase for thylakoid transport
Chloroplast stromal factors involved in regulating thylakoid protein targeting are poorly understood. We previously reported that in Arabidopsis thaliana, the stromal-localized chaperone HSP90C (plastid heat shock protein 90) interacted with the nuclear-encoded thylakoid lumen protein PsbO1 (PSII su...
Autores principales: | , , |
---|---|
Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Oxford University Press
2020
|
Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7906790/ https://www.ncbi.nlm.nih.gov/pubmed/32853383 http://dx.doi.org/10.1093/jxb/eraa399 |
_version_ | 1783655363833233408 |
---|---|
author | Jiang, Tim Mu, Bona Zhao, Rongmin |
author_facet | Jiang, Tim Mu, Bona Zhao, Rongmin |
author_sort | Jiang, Tim |
collection | PubMed |
description | Chloroplast stromal factors involved in regulating thylakoid protein targeting are poorly understood. We previously reported that in Arabidopsis thaliana, the stromal-localized chaperone HSP90C (plastid heat shock protein 90) interacted with the nuclear-encoded thylakoid lumen protein PsbO1 (PSII subunit O isoform 1) and suggested a role for HSP90C in aiding PsbO1 thylakoid targeting. Using in organello transport assays, particularly with model substrates naturally expressed in stroma, we showed that light, exogenous ATP, and HSP90C activity were required for Sec-dependent transport of green fluorescent protein (GFP) led by the PsbO1 thylakoid targeting sequence. Using a previously identified PsbO1T200A mutant, we provided evidence that a stronger interaction between HSP90C and PsbO1 better facilitated its stroma–thylakoid trafficking. We also demonstrated that SecY1, the channel protein of the thylakoid SEC translocase, specifically interacted with HSP90C in vivo. Inhibition of the chaperone ATPase activity suppressed the association of the PsbO1GFP–HSP90C complex with SecY1. Together with analyzing the expression and accumulation of a few other thylakoid proteins that utilize the SRP, TAT, or SEC translocation pathways, we propose a model in which HSP90C forms a guiding complex that interacts with thylakoid protein precursors and assists in their specific targeting to the thylakoid SEC translocon. |
format | Online Article Text |
id | pubmed-7906790 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2020 |
publisher | Oxford University Press |
record_format | MEDLINE/PubMed |
spelling | pubmed-79067902021-03-02 Plastid chaperone HSP90C guides precursor proteins to the SEC translocase for thylakoid transport Jiang, Tim Mu, Bona Zhao, Rongmin J Exp Bot Research Papers Chloroplast stromal factors involved in regulating thylakoid protein targeting are poorly understood. We previously reported that in Arabidopsis thaliana, the stromal-localized chaperone HSP90C (plastid heat shock protein 90) interacted with the nuclear-encoded thylakoid lumen protein PsbO1 (PSII subunit O isoform 1) and suggested a role for HSP90C in aiding PsbO1 thylakoid targeting. Using in organello transport assays, particularly with model substrates naturally expressed in stroma, we showed that light, exogenous ATP, and HSP90C activity were required for Sec-dependent transport of green fluorescent protein (GFP) led by the PsbO1 thylakoid targeting sequence. Using a previously identified PsbO1T200A mutant, we provided evidence that a stronger interaction between HSP90C and PsbO1 better facilitated its stroma–thylakoid trafficking. We also demonstrated that SecY1, the channel protein of the thylakoid SEC translocase, specifically interacted with HSP90C in vivo. Inhibition of the chaperone ATPase activity suppressed the association of the PsbO1GFP–HSP90C complex with SecY1. Together with analyzing the expression and accumulation of a few other thylakoid proteins that utilize the SRP, TAT, or SEC translocation pathways, we propose a model in which HSP90C forms a guiding complex that interacts with thylakoid protein precursors and assists in their specific targeting to the thylakoid SEC translocon. Oxford University Press 2020-08-27 /pmc/articles/PMC7906790/ /pubmed/32853383 http://dx.doi.org/10.1093/jxb/eraa399 Text en © The Author(s) 2020. Published by Oxford University Press on behalf of the Society for Experimental Biology. http://creativecommons.org/licenses/by/4.0/ This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited. |
spellingShingle | Research Papers Jiang, Tim Mu, Bona Zhao, Rongmin Plastid chaperone HSP90C guides precursor proteins to the SEC translocase for thylakoid transport |
title | Plastid chaperone HSP90C guides precursor proteins to the SEC translocase for thylakoid transport |
title_full | Plastid chaperone HSP90C guides precursor proteins to the SEC translocase for thylakoid transport |
title_fullStr | Plastid chaperone HSP90C guides precursor proteins to the SEC translocase for thylakoid transport |
title_full_unstemmed | Plastid chaperone HSP90C guides precursor proteins to the SEC translocase for thylakoid transport |
title_short | Plastid chaperone HSP90C guides precursor proteins to the SEC translocase for thylakoid transport |
title_sort | plastid chaperone hsp90c guides precursor proteins to the sec translocase for thylakoid transport |
topic | Research Papers |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7906790/ https://www.ncbi.nlm.nih.gov/pubmed/32853383 http://dx.doi.org/10.1093/jxb/eraa399 |
work_keys_str_mv | AT jiangtim plastidchaperonehsp90cguidesprecursorproteinstothesectranslocaseforthylakoidtransport AT mubona plastidchaperonehsp90cguidesprecursorproteinstothesectranslocaseforthylakoidtransport AT zhaorongmin plastidchaperonehsp90cguidesprecursorproteinstothesectranslocaseforthylakoidtransport |