Open AccessmRNAs encoding ribulose-1,5-bisphosphate carboxylase remain bound to polysomes but are not translated in amaranth seedlings transferred to darkness
Author(s) -
James O. Berry,
John P. Carr,
Daniel F. Klessig
Publication year - 1988
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.85.12.4190
Subject(s) - polysome , puromycin , darkness , protein biosynthesis , pyruvate carboxylase , biology , rubisco , ribosome , protein subunit , biochemistry , microbiology and biotechnology , messenger rna , ribulose 1,5 bisphosphate , translation (biology) , rna , photosynthesis , enzyme , botany , gene
When light-grown seedlings of amaranth are transferred to total darkness, synthesis of the large subunit (LS) and small subunit (SS) of ribulose-1,5-bisphosphate carboxylase [RbuP 2 Case; 3-phospho-D-glycerate carboxylase (dimerizing), EC 4.1.1.39] is rapidly depressed. This reduction in RbuP 2 Case synthesis occurs in the absence of any corresponding changes in levels of functional mRNA for either subunit. Four hours after light-to-dark transition little, if any, changes in the distribution of LS and SS mRNAs on polysomes could be detected. The association of these mRNAs with polysomes was authenticated by treatment with RNase A or puromycin. Furthermore, polysomes were able to synthesize LS and SS precursor in cell-free translation systems supplemented with inhibitors of initiation. Therefore, during a light-to-dark transition LS and SS mRNAs remained bound to polysomes but were not translatedin vivo , suggesting that control is exercised, in part, at the translational elongation step.