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Abstract : |
Posttranscriptional controls play important roles in the determination of gene expression. A major component of the regulation of gene expression is exerted at the level of mRNA stability. mRNAs can differ dramatically in their intrinsic stabilities. Eukaryotic mRNAs have a considerable range of halfأƒآ¢أ‚€أ‚“lives, from as short as few minutes to as long as several days. In parallel, specific mRNA decay pathways may also occur to control the quality of mRNA prior to translation. Nonsenseأƒآ¢أ‚€أ‚“mediated mRNA decay (NMD) is an example of a posttranscriptional mechanism that is used by cells to survey mRNA quality. By degrading abnormal transcripts that prematurely terminate translation, NMD prevents the production of truncated proteins that could have a dominantأƒآ¢أ‚€أ‚“negative effect for the cell. Thus, the stability of individual mRNAs reflects the interaction of general determinants with mRNAأƒآ¢أ‚€أ‚“specific sequence elements and transأƒآ¢أ‚€أ‚“acting proteins that function to dictate mRNA turnover. In this review, we present the major current conceived mechanisms that specify the stability of the normal human أƒإ½أ‚آ²أƒآ¢أ‚€أ‚“globin mRNA, as well as the surveillance mechanism of nonsenseأƒآ¢أ‚€أ‚“mediated mRNA decay, emphasizing aspects specific for this transcript., |
