RESUMO
mRNA degradation is a regulated process that can play an important role in determining the level of expression of specific genes. The rate at which a specific mRNA is degraded depends largely on specific cis-acting sequences located throughout the transcript. cis-Acting destabilizer sequences that promote increased rates of decay have been identified in several short-lived mRNAs. However, little is known about elements that promote stability, known as stabilizer elements (STEs), and how they function. The work presented here describes the characterization of a STE in the PGK1 transcript. The PGK1 stabilizer element (P-STE) has been delineated to a 64-nucleotide sequence from the coding region that can stabilize a chimeric transcript containing the instability elements from the 3'-untranslated region of the MFA2 transcript. The P-STE is located within the PGK1 coding region and functions when located in the translated portion of the transcript and at a minimum distance from the 3'-untranslated region. These results further support the link between translation and mRNA degradation. A conserved sequence in the TEF1/2 transcript has been identified that also functions as a STE, suggesting that this sequence element maybe a general stability determinant found in other yeast mRNAs.
