Sensory circuitry controls cytosolic calcium-mediated phytochrome B phototransduction.
Cell
; 186(6): 1230-1243.e14, 2023 03 16.
Article
em En
| MEDLINE
| ID: mdl-36931246
ABSTRACT
Although Ca2+ has long been recognized as an obligatory intermediate in visual transduction, its role in plant phototransduction remains elusive. Here, we report a Ca2+ signaling that controls photoreceptor phyB nuclear translocation in etiolated seedlings during dark-to-light transition. Red light stimulates acute cytosolic Ca2+ increases via phyB, which are sensed by Ca2+-binding protein kinases, CPK6 and CPK12 (CPK6/12). Upon Ca2+ activation, CPK6/12 in turn directly interact with and phosphorylate photo-activated phyB at Ser80/Ser106 to initiate phyB nuclear import. Non-phosphorylatable mutation, phyBS80A/S106A, abolishes nuclear translocation and fails to complement phyB mutant, which is fully restored by combining phyBS80A/S106A with a nuclear localization signal. We further show that CPK6/12 function specifically in the early phyB-mediated cotyledon expansion, while Ser80/Ser106 phosphorylation generally governs phyB nuclear translocation. Our results uncover a biochemical regulatory loop centered in phyB phototransduction and provide a paradigm for linking ubiquitous Ca2+ increases to specific responses in sensory stimulus processing.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fitocromo
/
Arabidopsis
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Proteínas de Arabidopsis
Idioma:
En
Revista:
Cell
Ano de publicação:
2023
Tipo de documento:
Article
País de afiliação:
China