Posttranslational regulation of photosynthetic activity via the TOR kinase in plants.
Sci Adv
; 10(25): eadj3268, 2024 Jun 21.
Article
em En
| MEDLINE
| ID: mdl-38896607
ABSTRACT
Chloroplasts are the powerhouse of the plant cell, and their activity must be matched to plant growth to avoid photooxidative damage. We have identified a posttranslational mechanism linking the eukaryotic target of rapamycin (TOR) kinase that promotes growth and the guanosine tetraphosphate (ppGpp) signaling pathway of prokaryotic origins that regulates chloroplast activity and photosynthesis in particular. We find that RelA SpoT homolog 3 (RSH3), a nuclear-encoded enzyme responsible for ppGpp biosynthesis, interacts directly with the TOR complex via a plant-specific amino-terminal region which is phosphorylated in a TOR-dependent manner. Down-regulating TOR activity causes a rapid increase in ppGpp synthesis in RSH3 overexpressors and reduces photosynthetic capacity in an RSH-dependent manner in wild-type plants. The TOR-RSH3 signaling axis therefore regulates the equilibrium between chloroplast activity and plant growth, setting a precedent for the regulation of organellar function by TOR.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Fotossíntese
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Transdução de Sinais
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Cloroplastos
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Arabidopsis
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Proteínas de Arabidopsis
Idioma:
En
Revista:
Sci Adv
Ano de publicação:
2024
Tipo de documento:
Article
País de afiliação:
França