Light regulation of protein synthesis factor EF-G in pea chloroplasts.
The activity of pea chloroplast elongation factor G (EF-G), a nuclear-coded protein required for the elongation cycle of chloroplast protein synthesis, is regulated in response to light. In pea seedlings germinated and grown under continuous white or red light, EF-G specific activity reaches a maximum between days 10 to 15, and then decreases. EF-G activity is almost undetectable in extracts from dark-grown seedlings. When 13-day dark-grown pea seedlings are transferred to light, EF-G specific activity reaches a higher value after 2 to 3 days than observed in seedlings grown under continuous light. The small and large subunits of ribulose bisphosphate carboxylase continue to accumulate after EF-G specific activity has reached maximum levels. Cytoplasmically synthesized components of the chloroplast protein synthetic apparatus, such as EF-G, may help coordinate cytoplasmic and nuclear events with chloroplast gene expression during light-induced chloroplast differentiation.
Akkaya
M S
MS
Department of Biochemistry, Ohio State University, Columbus 43210-1292.
Breitenberger
C A
CA
D002736:Chloroplasts / Q000378:metabolism* / Q000528:radiation effects; D003624:Darkness; D004926:Escherichia coli / Q000378:metabolism; D007887:Fabaceae / Q000254:growth & development / Q000378:metabolism*; D007700:Kinetics; D008027:Light; D020653:Peptide Elongation Factor G; D010445:Peptide Elongation Factors / Q000378:metabolism* / Q000528:radiation effects; D010946:Plants, Medicinal; D012270:Ribosomes / Q000378:metabolism; D013997:Time Factors
D020653:Peptide Elongation Factor G; D010445:Peptide Elongation Factors