Translation and a 42-nucleotide segment within the coding region of the mRNA encoded by the MAT alpha 1 gene are involved in promoting rapid mRNA decay in yeast.

AUTOR(ES)

Parker, R

RESUMO

In yeast, the mRNA encoded by the MAT alpha 1 gene is unstable (t1/2 = 5 min) and the mRNAs encoded by the ACT1 gene (t1/2 = 30 min) and the PGK1 gene (t1/2 = 45 min) are stable. To understand the RNA structural features that dictate mRNA decay rates in yeast, we have constructed PGK1/MAT alpha 1 and ACT1/MAT alpha 1 gene fusions and analyzed the decay rates of the resultant chimeric transcripts. Fusion of a MAT alpha 1 segment containing 73% of the coding region and the 3' untranslated region to either of the stable genes is sufficient to cause rapid decay of the chimeric mRNAs (t1/2 = 6-7.5 min). Sequences required for this rapid decay are not found in the MAT alpha 1 3' untranslated region but are located within a 42-nucleotide segment of the coding region that has a high content (8 out of 14) of rare codons. Introduction of a translational stop codon upstream of this region stabilizes the hybrid mRNAs, indicating that the rapid decay promoted by these sequences is dependent on ribosomal translocation.

Documentos Relacionados

• mRNA decay in spinach chloroplasts: psbA mRNA degradation is initiated by endonucleolytic cleavages within the coding region.
• A small segment of the MAT alpha 1 transcript promotes mRNA decay in Saccharomyces cerevisiae: a stimulatory role for rare codons.
• Accelerated mRNA decay in conditional mutants of yeast mRNA capping enzyme.
• Analysis of chimeric mRNAs derived from the STE3 mRNA identifies multiple regions within yeast mRNAs that modulate mRNA decay.
• Translation repression by GLD-1 protects its mRNA targets from nonsense-mediated mRNA decay in C. elegans