title: Expression of protein complexes and individual proteins upon transition of etioplasts to chloroplasts in pea (Pisum sativum).
abstract: The protein complexes of pea (Pisum sativum L.) etioplasts, etio-chloroplasts and chloroplasts were examined using 2D Blue Native/SDS-PAGE. The most prominent protein complexes in etioplasts were the ATPase and the Clp and FtsH protease complexes which probably have a crucial role in the biogenesis of etioplasts and chloroplasts. Also the cytochrome b(6)f (Cyt b(6)f) complex was assembled in the etioplast membrane, as well as Rubisco, at least partially, in the stroma. These complexes are composed of proteins encoded by both the plastid and nuclear genomes, indicating that a functional cross-talk exists between pea etioplasts and the nucleus. In contrast, the proteins and protein complexes that bind chlorophyll, with the PetD subunit and the entire Cyt b(6)f complex as an exception, did not accumulate in etioplasts. Nevertheless, some PSII core components such as PsbE and the luminal oxygen-evolvong complex (OEC) proteins PsbO and PsbP accumulated efficiently in etioplasts. After 6 h de-etiolation, a complete PSII core complex appeared with 40% of the maximal photochemical efficiency, but a fully functional PSII was recorded only after 24 h illumination. Similarly, the core complex of PSI was assembled after 6 h illumination, whereas the PSI-light-harvesting complex I was stably assembled only in chloroplasts illuminated for 24 h. Moreover, a battery of proteins responsible for defense against oxidative stress accumulated particularly in etioplasts, including the stromal and thylakoidal forms of ascorbate peroxidase, glutathione reductase and PsbS.
authors.affiliation: Department of Biology, University of Turku, FIN-20014 Turku, Finland.
authors.forename: Eira
authors.initials: E
authors.lastname: Kanervo
authors.forename: Munna
authors.initials: M
authors.lastname: Singh
authors.forename: Marjaana
authors.initials: M
authors.lastname: Suorsa
authors.forename: Virpi
authors.initials: V
authors.lastname: Paakkarinen
authors.forename: Eveliina
authors.initials: E
authors.lastname: Aro
authors.forename: Natalia
authors.initials: N
authors.lastname: Battchikova
authors.forename: Eva-Mari
authors.initials: EM
authors.lastname: Aro
mesh_terms: D002736:Chloroplasts / Q000502:physiology* / Q000648:ultrastructure; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D008027:Light; D018532:Pisum sativum / Q000166:cytology* / Q000235:genetics / Q000378:metabolism*; D010788:Photosynthesis / Q000502:physiology; D045332:Photosystem II Protein Complex / Q000235:genetics / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D045332:Photosystem II Protein Complex; D010940:Plant Proteins