title: Dynamic regulation of genome-wide pre-mRNA splicing and stress tolerance by the Sm-like protein LSm5 in Arabidopsis.
abstract: BACKGROUND
  Sm-like proteins are highly conserved proteins that form the core of the U6 ribonucleoprotein and function in several mRNA metabolism processes, including pre-mRNA splicing. Despite their wide occurrence in all eukaryotes, little is known about the roles of Sm-like proteins in the regulation of splicing.
  
  
  RESULTS
  Here, through comprehensive transcriptome analyses, we demonstrate that depletion of the Arabidopsis supersensitive to abscisic acid and drought 1 gene (SAD1), which encodes Sm-like protein 5 (LSm5), promotes an inaccurate selection of splice sites that leads to a genome-wide increase in alternative splicing. In contrast, overexpression of SAD1 strengthens the precision of splice-site recognition and globally inhibits alternative splicing. Further, SAD1 modulates the splicing of stress-responsive genes, particularly under salt-stress conditions. Finally, we find that overexpression of SAD1 in Arabidopsis improves salt tolerance in transgenic plants, which correlates with an increase in splicing accuracy and efficiency for stress-responsive genes.
  
  
  CONCLUSIONS
  We conclude that SAD1 dynamically controls splicing efficiency and splice-site recognition in Arabidopsis, and propose that this may contribute to SAD1-mediated stress tolerance through the metabolism of transcripts expressed from stress-responsive genes. Our study not only provides novel insights into the function of Sm-like proteins in splicing, but also uncovers new means to improve splicing efficiency and to enhance stress tolerance in a higher eukaryote.
authors.forename: Peng
authors.initials: P
authors.lastname: Cui
authors.forename: Shoudong
authors.initials: S
authors.lastname: Zhang
authors.forename: Feng
authors.initials: F
authors.lastname: Ding
authors.forename: Shahjahan
authors.initials: S
authors.lastname: Ali
authors.forename: Liming
authors.initials: L
authors.lastname: Xiong
mesh_terms: D017398:Alternative Splicing; D017360:Arabidopsis / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D017353:Gene Deletion; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D056726:Genetic Association Studies; D012322:RNA Precursors / Q000235:genetics*; D018749:RNA, Plant / Q000235:genetics; D016601:RNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D055049:Salt Tolerance / Q000235:genetics; D016415:Sequence Alignment; D017423:Sequence Analysis, RNA; D013312:Stress, Physiological
chemical_list: D029681:Arabidopsis Proteins; D012322:RNA Precursors; D018749:RNA, Plant; D016601:RNA-Binding Proteins; C443479:sad1 protein, Arabidopsis