Molecular evidence that the eukaryotic THO/TREX complex is required for efficient transcription elongation.
THO/TREX is a conserved eukaryotic complex formed by the core THO complex plus proteins involved in mRNA metabolism and export such as Sub2 and Yra1. Mutations in any of the THO/TREX structural genes cause pleiotropic phenotypes such as transcription impairment, increased transcription-associated recombination, and mRNA export defects. To assay the relevance of THO/TREX complex in transcription, we performed in vitro transcription elongation assays in mutant cell extracts using supercoiled DNA templates containing two G-less cassettes. With these assays, we demonstrate that hpr1delta, tho2delta, and mft1delta mutants of the THO complex and sub2 mutants show significant reductions in the efficiency of transcription elongation. The mRNA expression defect of hpr1delta mutants was not due to an increase in mRNA decay, as determined by mRNA half-life measurements and mRNA time course accumulation experiments in the absence of Rrp6p exoribonuclease. This work demonstrates that THO and Sub2 are required for efficient transcription elongation, providing further evidence for the coupling between transcription and mRNA metabolism and export.
Rondón
Ana G
AG
Departamento de Genética, Facultad de Biología, Universidad de Sevilla, Avenida Reina Mercedes 6, 41012 Sevilla, Spain.
Jimeno
Sonia
S
García-Rubio
María
M
Aguilera
Andrés
A
D000251:Adenosine Triphosphatases / Q000235:genetics; D001692:Biological Transport; D015152:Blotting, Northern; D002352:Carrier Proteins / Q000235:genetics; D027682:Cation Transport Proteins; D004278:DNA, Superhelical / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics* / Q000502:physiology; D007700:Kinetics; D024101:Mitochondrial Proteins; D008957:Models, Genetic; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics; D010641:Phenotype; D010957:Plasmids / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics; D013997:Time Factors; D014157:Transcription Factors / Q000235:genetics; D014158:Transcription, Genetic
D002352:Carrier Proteins; D027682:Cation Transport Proteins; D004278:DNA, Superhelical; D005656:Fungal Proteins; C063494:HPR1 protein, S cerevisiae; C109160:MMT1 protein, S cerevisiae; D024101:Mitochondrial Proteins; D009687:Nuclear Proteins; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D029701:Saccharomyces cerevisiae Proteins; C405934:THO2 protein, S cerevisiae; D014157:Transcription Factors; C105887:YRA1 protein, S cerevisiae; D000251:Adenosine Triphosphatases; C027900:RNA-dependent ATPase