Differential phosphorylation of thylakoid proteins in mesophyll and bundle sheath chloroplasts from maize plants grown under low or high light.
Proteomics
; 12(18): 2852-61, 2012 Sep.
Article
en En
| MEDLINE
| ID: mdl-22833285
In C4 plants, such as maize, the photosynthetic apparatus is partitioned over two cell types called mesophyll (M) and bundle sheath (BS), which have different structure and specialization of the photosynthetic thylakoid membranes. We characterized protein phosphorylation in thylakoids of the two cell types from maize grown under either low or high light. Western blotting with phosphothreonine antibodies and ProQ phosphostaining detected light-dependent changes in the protein phosphorylation patterns. LC-MS/MS with alternating CID and electron transfer dissociation sequencing of peptide ions mapped 15 protein phosphorylation sites. Phosphorylated D2, CP29, CP26, Lhcb2 proteins, and ATPsynthase were found only in M membranes. A previously unknown phosphorylation site was mapped in phosphoenolpyruvate carboxykinase from the BS cells. Phosphorylation stoichiometry was calculated from the ratios of normalized ion currents for phosphorylated to nonphosphorylated peptide pairs from the D1, D2, CP43, and PbsH proteins of photosystem II (PSII). Every PSII in M thylakoids contained on average 1.5 ± 0.1 or 2.3 ± 0.2 phosphoryl groups in plants grown under either low or high light, while in BS membranes the corresponding numbers were 0.25 ± 0.1 or 0.7 ± 0.2, respectively. It is suggested that the phosphorylation level, as well as turnover of PSII depend on the structure of thylakoids.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Fosfoproteínas
/
Proteínas de Plantas
/
Zea mays
/
Tilacoides
/
Complejo de Proteína del Fotosistema II
Idioma:
En
Revista:
Proteomics
Asunto de la revista:
BIOQUIMICA
Año:
2012
Tipo del documento:
Article
País de afiliación:
Suecia
Pais de publicación:
Alemania