title: Alternative 3' pre-mRNA processing in Saccharomyces cerevisiae is modulated by Nab4/Hrp1 in vivo.
abstract: 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.
authors.affiliation: Biochemistry and Biophysics, University of California San Francisco, San Francisco, California, United States of America.
authors.forename: Karen S
authors.initials: KS
authors.lastname: Kim Guisbert
authors.forename: Hao
authors.initials: H
authors.lastname: Li
authors.forename: Christine
authors.initials: C
authors.lastname: Guthrie
mesh_terms: D020413:3' Untranslated Regions / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D017398:Alternative Splicing / Q000187:drug effects / Q000235:genetics*; D003300:Copper / Q000633:toxicity; D015966:Gene Expression Regulation, Fungal / Q000187:drug effects; D006868:Hydrolysis / Q000187:drug effects; D026723:Polyadenylation / Q000187:drug effects / Q000235:genetics*; D012322:RNA Precursors / Q000737:chemistry / Q000378:metabolism*; D012331:RNA, Fungal / Q000737:chemistry / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000235:genetics* / Q000502:physiology; D029701:Saccharomyces cerevisiae Proteins / Q000502:physiology*; D039221:mRNA Cleavage and Polyadenylation Factors / Q000502:physiology*
chemical_list: D020413:3' Untranslated Regions; C512636:HRP1 protein, S cerevisiae; D012322:RNA Precursors; D012331:RNA, Fungal; D029701:Saccharomyces cerevisiae Proteins; D039221:mRNA Cleavage and Polyadenylation Factors; D003300:Copper