Dephosphorylation of photosystem II core proteins is light-regulated in vivo.
AUTOR(ES)
Elich, T D
RESUMO
A number of photosystem II (PSII)-associated proteins, including D1, D2, CP43 and LHCII, are phosphorylated post-translationally by a membrane-bound, redox-regulated kinase activity. In vitro studies have demonstrated that these proteins can be dephosphorylated by membrane-bound phosphatase activity, reportedly insensitive to light or redox control. We demonstrate here that the PSII core proteins, D1, D2 and CP43, undergo light-stimulated, linear electron-transport-independent dephosphorylation in vivo. The in vivo dephosphorylation of D1 was characterized further and shown to depend upon light intensity, and to occur throughout the visible light spectrum with characteristics most consistent with light absorption by chlorophyll. PSII core protein dephosphorylation in vivo was stimulated by photosystem I (PSI)-specific far-red light, and inhibited by 2,5-dibromo-3-methyl-6-isopropyl-p-benzoquinone, an inhibitor of plastoquinol oxidation by the cytochrome b6f complex. Based on these findings, we propose that PSI excitation is involved in regulating dephosphorylation of PSII core proteins in vivo.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=413940Documentos Relacionados
- Fast light-regulated genes of Neurospora crassa.
- Light-Regulated Gravitropism in Seedling Roots of Maize 1
- A novel light-regulated promoter is conserved in cereal and dicot chloroplasts.
- Heterodimerization between light-regulated and ubiquitously expressed Arabidopsis GBF bZIP proteins.
- In vivo and in vitro footprinting of a light-regulated promoter in the cyanobacterium Fremyella diplosiphon.