The rice CK2 kinase regulates trafficking of phosphate transporters in response to phosphate levels.
Plant Cell
; 27(3): 711-23, 2015 Mar.
Article
em En
| MEDLINE
| ID: mdl-25724641
ABSTRACT
Phosphate transporters (PTs) mediate phosphorus uptake and are regulated at the transcriptional and posttranslational levels. In one key mechanism of posttranslational regulation, phosphorylation of PTs affects their trafficking from the endoplasmic reticulum (ER) to the plasma membrane. However, the kinase(s) mediating PT phosphorylation and the mechanism leading to ER retention of phosphorylated PTs remain unclear. In this study, we identified a rice (Oryza sativa) kinase subunit, CK2ß3, which interacts with PT2 and PT8 in a yeast two-hybrid screen. Also, the CK2α3/ß3 holoenzyme phosphorylates PT8 under phosphate-sufficient conditions. This phosphorylation inhibited the interaction of PT8 with PHOSPHATE TRANSPORTER TRAFFIC FACILITATOR1, a key cofactor regulating the exit of PTs from the ER to the plasma membrane. Additionally, phosphorus starvation promoted CK2ß3 degradation, relieving the negative regulation of PT phosphorus-insufficient conditions. In accordance, transgenic expression of a nonphosphorylatable version of OsPT8 resulted in elevated levels of that protein at the plasma membrane and enhanced phosphorus accumulation and plant growth under various phosphorus regimes. Taken together, these results indicate that CK2α3/ß3 negatively regulates PTs and phosphorus status regulates CK2α3/ß3.
Texto completo:
1
Bases de dados:
MEDLINE
Assunto principal:
Fosfatos
/
Proteínas de Plantas
/
Oryza
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Proteínas de Transporte de Fosfato
/
Caseína Quinase II
Idioma:
En
Revista:
Plant Cell
Assunto da revista:
BOTANICA
Ano de publicação:
2015
Tipo de documento:
Article
País de afiliação:
China