The stability of a messenger RNA (mRNA) is a highly regulated and important aspect of gene expression. Proteins that regulate mRNA stability often bind to 3' untranslated region (UTR) sequence elements. The eukaryotic Puf proteins are one class of 3'UTR binding proteins that regulate the stability and expression of their target transcripts. Several global genome analyses have identified hundreds of potential mRNA targets of the Saccharomyces cerevisiae Puf proteins, however only three mRNA targets for these proteins have been characterized thus far. After direct testing of nearly forty candidate mRNAs, I have established three of these as true mRNA targets of Puf-mediated decay in yeast, YHB1, HXK1 and TIF1. In a novel finding, multiple Puf proteins, including Puf1p, regulate HXK1 and TIF1 mRNAs in combination. TIF1 mRNA decay can be stimulated individually by Puf1p and Puf5p, but the combination of both proteins is required for full regulation. This Puf-mediated decay requires the presence of two UGUA binding sites within the TIF1 3' UTR, with one site regulated by Puf5p and the other by both Puf1p and Puf5p. The stability of the endogenously transcribed HXK1 mRNA, cellular levels of Hxk1 protein activity, and HXK1 3'UTR-directed decay are affected by Puf1p and Puf5p as well as Puf4p. YHB1 mRNA decay is mediated by Puf5p and also requires a UGUA sequence element.Hxklp is upregulated in PUF deletion yeast To test the effects of Puf proteins on HXK1 gene expression at the cellular level, the ... However, Hxklp prefers fructose to glucose phosphorylation 3:1, whereas Hxk2p phosphorylates fructose and glucose ... mRNA by Puf2p, neither the HXK1 full-length mRNA decay nor the Hxklp activity appears to be affected by Pul2p. Moreover, the slight stabilization of PGK1/HXK1 mRNA in the absence of PUF4 does not coordinate with the more drasticanbsp;...
|Title||:||Puf1p-mediatedmRNA Decay and Combinatorial Control of MRNA Stability by the Yeast Puf Proteins|
|Author||:||Randi J. Ulbricht|
|Publisher||:||ProQuest - 2008|