Alternative 3' pre-mRNA processing in Saccharomyces cerevisiae is modulated by Nab4/Hrp1 in vivo

• Published in: PLoS biology 2007-01, Vol.5 (1), p.e6
• Main Authors: Kim Guisbert, Karen S, Li, Hao, Guthrie, Christine
• Format: Article
• Language: English
• Subjects: 3' Untranslated Regions - drug effects; 3' Untranslated Regions - genetics; 3' Untranslated Regions - metabolism; Alternative Splicing - drug effects; Alternative Splicing - genetics; Binding sites; Bioinformatics; Brewer's yeast; Cell Biology; Copper; Copper - toxicity; Eukaryotes; Gene Expression Regulation, Fungal - drug effects; Genetic aspects; Genetics and Genomics; Hydrolysis - drug effects; Molecular Biology; mRNA Cleavage and Polyadenylation Factors - physiology; Polyadenylation - drug effects; Polyadenylation - genetics; Proteins; RNA polymerase; RNA Precursors - chemistry; RNA Precursors - metabolism; RNA, Fungal - chemistry; RNA, Fungal - metabolism; Saccharomyces; Saccharomyces cerevisiae; Saccharomyces cerevisiae - drug effects; Saccharomyces cerevisiae - genetics; Saccharomyces cerevisiae - physiology; Saccharomyces cerevisiae Proteins - physiology; Site selection
• ISSN: 1545-7885; 1544-9173; 1545-7885
• DOI: 10.1371/journal.pbio.0050006

The Saccharomyces cerevisiae RNA-binding protein Nab4/Hrp1 is a component of the cleavage factor complex required for 3' pre-mRNA processing. Although the precise role of Nab4/Hrp1 remains unclear, it has been implicated in correct positioning of the cleavage site in vitro. Here, we show that mutation or overexpression of NAB4/HRP1 alters polyA cleavage site selection in vivo. Using bioinformatic analysis, we identified four related motifs that are statistically enriched in Nab4-associated transcripts; each motif is similar to the known binding site for Nab4/Hrp1. Site-directed mutations in predicted Nab4/Hrp1 binding elements result in decreased use of adjacent cleavage sites. Additionally, we show that the nab4-7 mutant displays a striking resistance to toxicity from excess copper. We identify a novel target of alternative 3' pre-mRNA processing, CTR2, and demonstrate that CTR2 is required for the copper resistance phenotype in the nab4-7 strain. We propose that alternative 3' pre-mRNA processing is mediated by a Nab4-based mechanism and that these alternative processing events could help control gene expression as part of a physiological response in S. cerevisiae.