title: Function of yeast and amphioxus tRNA ligase in IRE1alpha-dependent XBP1 mRNA splicing.
abstract: During their maturation step, transfer RNAs (tRNAs) undergo excision of their introns by specific splicing. Although tRNA splicing is a molecular event observed in all domains of life, the machinery of the ligation reaction has diverged during evolution. Yeast tRNA ligase 1 (TRL1) is a multifunctional protein that alone catalyzes RNA ligation in tRNA splicing, whereas three molecules [RNA ligase (RNL), Clp1, and PNK/CPDase] are necessary for RNA ligation in tRNA splicing in amphioxi. RNA ligation not only occurs in tRNA splicing, but also in yeast HAC1 mRNA splicing and in animal X-box binding protein 1 (XBP1) mRNA splicing under conditions of endoplasmic reticulum (ER) stress. Yeast TRL1 is known to function as an RNA ligase for HAC1 mRNA splicing, whereas the RNA ligase for XBP1 mRNA splicing is unknown in animals. We examined whether yeast and amphioxus RNA ligases for tRNA splicing function in RNA ligation in mammalian XBP1 splicing. Both RNA ligases functioned in RNA ligation in mammalian XBP1 splicing in vitro. Interestingly, Clp1, and PNK/CPDase were not necessary for exon-exon ligation in XBP1 mRNA by amphioxus RNL. These results suggest that RNA ligase for tRNA splicing might therefore commonly function as an RNA ligase for XBP1 mRNA splicing.
authors.affiliation: Iwawaki Laboratory, Advanced Scientific Research Leaders Development Unit, Gunma University, 3-39-22 Showa-machi, Maebashi, Gunma 371-8511, Japan. iwawaki@gunma-u.ac.jp
authors.forename: Takao
authors.initials: T
authors.lastname: Iwawaki
authors.forename: Mio
authors.initials: M
authors.lastname: Tokuda
mesh_terms: D050976:Basic-Leucine Zipper Transcription Factors / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics*; D004722:Endoribonucleases / Q000235:genetics / Q000378:metabolism*; D057809:HEK293 Cells; D006367:HeLa Cells; D006801:Humans; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D011130:RNA Ligase (ATP) / Q000235:genetics / Q000378:metabolism*; D012326:RNA Splicing; D012333:RNA, Messenger / Q000235:genetics*; D012343:RNA, Transfer / Q000235:genetics; D000071701:Regulatory Factor X Transcription Factors; D012097:Repressor Proteins / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics*; D000071717:X-Box Binding Protein 1
chemical_list: D050976:Basic-Leucine Zipper Transcription Factors; D004268:DNA-Binding Proteins; C091341:HAC1 protein, S cerevisiae; D012333:RNA, Messenger; D000071701:Regulatory Factor X Transcription Factors; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D000071717:X-Box Binding Protein 1; C000605543:XBP1 protein, human; D012343:RNA, Transfer; C528229:ERN1 protein, human; D017346:Protein Serine-Threonine Kinases; D004722:Endoribonucleases; D011130:RNA Ligase (ATP); C507673:Trl1 protein, S cerevisiae