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Spermine Specifically Inhibits the RRF (ribosome recycling factor) Reaction: In its presence, RRF still Stimulates Protein Synthesis
Author(s) -
Iwakura Nobuhiro,
Giuliodori Annamaria,
Kaji Akira,
Kaji Hideko
Publication year - 2015
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.29.1_supplement.892.1
Subject(s) - spermine , spermidine , protein biosynthesis , in vivo , messenger rna , microbiology and biotechnology , chemistry , ribosome , mutant , biochemistry , translation (biology) , transfer rna , biology , rna , enzyme , gene , genetics
Although spermine (Spm) is not present in E . coli , 100 µM Spm inhibited the disassembly of the model PoTC 100%. On the other hand, in vitro incorporation of amino acids programmed by synthetic mRNA similar to naturally occurring mRNA with canonical initiation and termination signals was stimulated 100% by RRF even in the presence of 100 µM of Spm. These observations indicate that RRF functions to stimulate protein synthesis at steps in addition to the recycling step; our current hypothesis is that RRF stimulates the translocation step. To test this, conventional assay of the translocation as well as the single ribosome translocation step are examined. The inhibitory action of Spm on the RRF reaction is at steps of the release of mRNA and tRNA but not on the binding or release of RRF to and from the ribosome. The inhibitory effect of Spm was partially reversed by IF3. In E . coli mutant unable to metabolize spermidine in vivo , 25% increase of RRF amount was observed. Furthermore, addition of 4 mM spermidine to the culture media of this mutant raised in vivo concentration of RRF about 100%.