The stress induced caleosin, RD20/CLO3, acts as a negative regulator of GPA1 in Arabidopsis.
Plant Mol Biol
; 107(3): 159-175, 2021 Oct.
Article
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| MEDLINE
| ID: mdl-34599731
ABSTRACT
KEY MESSAGE A stress induced calcium-binding protein, RD20/CLO3 interacts with the alpha subunit of the heterotrimeric G-protein complex in Arabidopsis and affects etiolation and leaf morphology. Heterotrimeric G proteins and calcium signaling have both been shown to play a role in the response to environmental abiotic stress in plants; however, the interaction between calcium-binding proteins and G-protein signaling molecules remains elusive. We investigated the interaction between the alpha subunit of the heterotrimeric G-protein complex, GPA1, of Arabidopsis thaliana with the calcium-binding protein, the caleosin RD20/CLO3, a gene strongly induced by drought, salt and abscisic acid. The proteins were found to interact in vivo by bimolecular fluorescent complementation (BiFC); the interaction was localized to the endoplasmic reticulum and to oil bodies within the cell. The constitutively GTP-bound GPA1 (GPA1QL) also interacts with RD20/CLO3 as well as its EF-hand mutant variations and these interactions are localized to the plasma membrane. The N-terminal portion of RD20/CLO3 was found to be responsible for the interaction with GPA1 and GPA1QL using both BiFC and yeast two-hybrid assays. RD20/CLO3 contains a single calcium-binding EF-hand in the N-terminal portion of the protein; disruption of the calcium-binding capacity of the protein obliterates interaction with GPA1 in in vivo assays and decreases the interaction between the caleosin and the constitutively active GPA1QL. Analysis of rd20/clo3 mutants shows that RD20/CLO3 plays a key role in the signaling pathway controlling hypocotyl length in dark grown seedlings and in leaf morphology. Our findings indicate a novel role for RD20/CLO3 as a negative regulator of GPA1.
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Bases de datos:
MEDLINE
Asunto principal:
Estrés Fisiológico
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Proteínas de Unión al Calcio
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Arabidopsis
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Proteínas de Arabidopsis
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Subunidades alfa de la Proteína de Unión al GTP
Idioma:
En
Revista:
Plant Mol Biol
Asunto de la revista:
BIOLOGIA MOLECULAR
/
BOTANICA
Año:
2021
Tipo del documento:
Article
País de afiliación:
Canadá