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Redundancy of non‐AUG initiators: a clever mechanism to enhance the efficiency of translation in yeast
Author(s) -
Wang ChienChia,
Chang KuangJung,
Lin Grace,
Men LeeChung
Publication year - 2006
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.20.4.a106
Subject(s) - saccharomyces cerevisiae , redundancy (engineering) , ribosome , gene , förster resonance energy transfer , yeast , translation (biology) , chemistry , computational biology , biophysics , genetics , microbiology and biotechnology , stereochemistry , biology , biochemistry , computer science , physics , messenger rna , rna , fluorescence , quantum mechanics , operating system
It was recently shown that ALA1 , the only alanyl‐tRNA synthetase gene in Saccharomyces cerevisiae , uses two successive ACG triplets as the translation initiators for its mitochondrial form. Evidence presented here argues that the second ACG triplet not only acts as a remedial initiation site for scanning ribosomes that skip the first ACG, but also enhances the activity of the preceding initiator by providing a preferable “A” at its relative position +4. Therefore, ALA1 constructs with redundant ACG initiators exhibit stronger complementing activity and express a higher level of protein than do those with a single ACG initiator. A similar scenario is seen when a single or redundant ACG triplets are placed in the positions of the first and second AUG initiators of VAS1 , which serve as the start sites of the mitochondrial and cytoplasmic forms of valyl‐tRNA synthetase, respectively. Cumulatively, the results suggest that this feature of redundancy of non‐AUG initiators in a single mRNA per se may represent a novel paradigm for improving the efficiency of a poor or otherwise non‐productive initiation event. (This work was supported in part by Grant NSC 94‐2311‐B‐008‐009 (to C. C. W.) from the National Science Council (Taiwan) and by Grant 94‐2001‐INER‐EE‐009 (to C. C. W.) from the Institute of Nuclear Energy Research, Atomic Energy Council (Taiwan).)