title: Link of NTR-mediated spliceosome disassembly with DEAH-box ATPases Prp2, Prp16, and Prp22.
abstract: The DEAH-box ATPase Prp43 is required for disassembly of the spliceosome after the completion of splicing or after the discard of the spliceosome  due to a splicing defect. Prp43 associates with Ntr1 and Ntr2 to form the NTR complex and is recruited to the spliceosome via the interaction of Ntr2 and U5 component Brr2. Ntr2 alone can bind to U5 and to the spliceosome. To understand how NTR might mediate the disassembly of spliceosome intermediates, we arrested the spliceosome at various stages of the assembly pathway and assessed  its susceptibility to disassembly. We found that NTR could catalyze the disassembly of affinity-purified spliceosomes arrested specifically after the ATP-dependent action of DEAH-box ATPase Prp2, Prp16, or Prp22 but not at steps before the action of these ATPases or upon their binding to the spliceosome. These results link spliceosome disassembly to the functioning of splicing ATPases. Analysis of the binding of Ntr2 to each splicing complex has revealed that the presence of Prp16 and Slu7, which also interact with Brr2, has a negative impact on Ntr2 binding. Our study provides insights into the mechanism by which NTR can be recruited to the spliceosome to mediate the disassembly of spliceosome intermediates when the spliceosome pathway is retarded, while disassembly is prevented  in normal reactions.
authors.affiliation: Institute of Microbiology and Immunology, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Hsin-Chou
authors.initials: HC
authors.lastname: Chen
authors.forename: Chi-Kang
authors.initials: CK
authors.lastname: Tseng
authors.forename: Rong-Tzong
authors.initials: RT
authors.lastname: Tsai
authors.forename: Che-Sheng
authors.initials: CS
authors.lastname: Chung
authors.forename: Soo-Chen
authors.initials: SC
authors.lastname: Cheng
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism*; D053487:DEAD-box RNA Helicases / Q000378:metabolism*; D011485:Protein Binding; D020365:RNA Helicases / Q000378:metabolism*; D000072260:RNA Splicing Factors; D017411:Ribonucleoproteins, Small Nuclear / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*; D017381:Spliceosomes / Q000378:metabolism*
chemical_list: C544745:Cwc25 protein, S cerevisiae; C507653:Ntr2 protein, S cerevisiae; D000072260:RNA Splicing Factors; D017411:Ribonucleoproteins, Small Nuclear; C095479:SLU7 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; C507652:Spp382 protein, S cerevisiae; D000251:Adenosine Triphosphatases; C075669:PRP16 protein, S cerevisiae; C066490:PRP2 protein, S cerevisiae; C067135:PRP22 protein, S cerevisiae; D053487:DEAD-box RNA Helicases; D020365:RNA Helicases