Project description:Comparison of WT, xrn1 delta and upf1 delta strains were used in a tiling array to yield genomic regions regulated by these proteins The supplementary CHP files record either the signal in log2 space or the p-values in linear space, per TAS output. The CHP files are further divided between UPF1 delta vs. WT and XRN1 delta vs. WT.
Project description:To determine the effects of inactivation of both the nosense-mediated mRNA decay pathway and the general 5' to 3' decay pathway on yeast mRNA decay, we compared the expression profiles of the wild-type, xrn1, xrn1 upf1, xrn1 nmd2, and xrn1 upf3 strains.
Project description:Upf1 is a master regulator of nonsense-mediated mRNA decay (NMD), an mRNA surveillance and degradation pathway conserved from yeast to human. In S. cerevisiae, Upf1 exists in two distinct complexes with factors that mediate NMD activation or 5'-3' mRNA degradation. We combined endogenous purifications and biochemical reconstitutions of yeast Upf1 complexes with structural analyses and biochemical assays to elucidate the molecular mechanisms driving the mutually exclusive organization of the Upf1-5'-3' and Upf1-2-3 complexes. We show that yeast Upf1 is in a constitutive complex whereby its CH, RecA and C-terminal domains interact with the mRNA decapping factor Dcp2, NMD-associated proteins Nmd4 and Ebs1, and the 5'-3' exoribonuclease Xrn1, respectively. Together, the interacting surfaces and closed conformation of Upf1 in the Upf1-5'-3' complex sterically obstruct the binding of Upf2-3. Our work points to a major restructuring upon recruitment of these factors during NMD and provides insights into evolutionary divergence amongst species.
