1. Mapping the translation initiation landscape of an S. cerevisiae gene using fluorescent proteins.
- Author
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Ben-Yehezkel, Tuval, Zur, Hadas, Marx, Tzipy, Shapiro, Ehud, and Tuller, Tamir
- Subjects
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TRANSLATION initiation factors (Biochemistry) , *FLUORESCENT proteins , *GENE mapping , *MESSENGER RNA , *GENE expression , *SACCHAROMYCES cerevisiae , *REPORTER genes , *NUCLEOTIDE sequence - Abstract
Abstract: Accurate and efficient gene expression requires that protein translation initiates from mRNA transcripts with high fidelity. At the same time, indiscriminate initiation of translation from multiple ATG start-sites per transcript has been demonstrated, raising fundamental questions regarding the rate and rationale governing alternative translation initiation. We devised a sensitive fluorescent reporter assay for monitoring alternative translation initiation. To demonstrate it, we map the translation initiation landscape of a Saccharomyces cerevisiae gene (RMD1) with a typical ATG sequence context profile. We found that up to 3%–5% of translation initiation events occur from alternative out-of-frame start codons downstream of the main ATG. Initiation from these codons follows the ribosome scanning model: initiation rates from different start sites are determined by ATG order, rather than their context strength. Genomic analysis of S. cerevisiae further supports the scanning model: ATG codons downstream rather than upstream of the main ATG tend to have higher context scores. [Copyright &y& Elsevier]
- Published
- 2013
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