Open AccessEbs1p, a Negative Regulator of Gene Expression Controlled by the Upf Proteins in the Yeast Saccharomyces cerevisiae
Author(s) -
Amanda S. Ford,
Qiaoning Guan,
Eric C. Neeno-Eckwall,
Michael R. Culbertson
Publication year - 2006
Publication title -
eukaryotic cell
Language(s) - English
Resource type - Journals
eISSN - 1535-9778
pISSN - 1535-9786
DOI - 10.1128/ec.5.2.301-312.2006
Subject(s) - biology , saccharomyces cerevisiae , nonsense mediated decay , translation (biology) , gene , gene expression , microbiology and biotechnology , mutant , regulation of gene expression , gene product , rna binding protein , messenger rna , eukaryotic translation , genetics , rna , rna splicing
Mutations inEBS1 were identified inSaccharomyces cerevisiae that cosuppress missense, frameshift, and nonsense mutations. Evidence from studies of loss of function and overexpression ofEBS1 suggests that Ebs1p affects gene expression by inhibiting translation and that a loss ofEBS1 function causes suppression by increasing the rate of translation. Changes inEBS1 expression levels alter the expression of wild-type genes, but, in general, no changes in mRNA abundance were associated with a loss of function or overexpression ofEBS1 . Translation of alacZ reporter was increased in strains carrying anebs1-Δ mutant gene, whereas translation was decreased whenEBS1 was overexpressed. The cap binding protein eIF-4E copurifies with Ebs1p in the absence of RNA, suggesting that the two proteins interact in vivo. Although physical and genetic interactions were detected between Ebs1p and Dcp1p, copurification was RNase sensitive, and changes in the expression of Ebs1p had little to no effect on decapping of theMFA2 transcript. The combined results suggest that Ebs1p inhibits translation, most likely through effects on eIF-4E rather than on decapping. Finally,EBS1 transcript levels are under the control of nonsense-mediated mRNA decay (NMD), providing the first example of an NMD-sensitive transcript whose protein product influences a step in gene expression required for NMD.