The STN8 kinase-PBCP phosphatase system is responsible for high-light-induced reversible phosphorylation of the PSII inner antenna subunit CP29 in rice.
Plant J
; 89(4): 681-691, 2017 Feb.
Article
en En
| MEDLINE
| ID: mdl-27813190
ABSTRACT
Reversible phosphorylation of thylakoid light-harvesting proteins is a mechanism to compensate for unbalanced excitation of photosystem I (PSI) versus photosystem II (PSII) under limiting light. In monocots, an additional phosphorylation event on the PSII antenna CP29 occurs upon exposure to excess light, enhancing resistance to light stress. Different from the case of the major LHCII antenna complex, the STN7 kinase and its related PPH1 phosphatase were proven not to be involved in CP29 phosphorylation, indicating that a different set of enzymes act in the high-light (HL) response. Here, we analyze a rice stn8 mutant in which both PSII core proteins and CP29 phosphorylation are suppressed in HL, implying that STN8 is the kinase catalyzing this reaction. In order to identify the phosphatase involved, we produced a recombinant enzyme encoded by the rice ortholog of AtPBCP, antagonist of AtSTN8, which catalyzes the dephosphorylation of PSII core proteins. The recombinant protein was active in dephosphorylating P-CP29. Based on these data, we propose that the activities of the OsSTN8 kinase and the antagonistic OsPBCP phosphatase, in addition to being involved in the repair of photo-damaged PSII, are also responsible for the HL-dependent reversible phosphorylation of the inner antenna CP29.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Proteínas de Plantas
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Proteínas Quinasas
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Oryza
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Fosfoproteínas Fosfatasas
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Complejo de Proteína del Fotosistema II
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Luz
Idioma:
En
Revista:
Plant J
Asunto de la revista:
BIOLOGIA MOLECULAR
/
BOTANICA
Año:
2017
Tipo del documento:
Article
País de afiliación:
Italia