Nab2p and the Thp1p-Sac3p complex functionally interact at the interface between transcription and mRNA metabolism Journal Article
| Authors: | Gallardo, M.; Luna, R.; Erdjument-Bromage, H.; Tempst, P.; Aguilera, A. |
| Article Title: | Nab2p and the Thp1p-Sac3p complex functionally interact at the interface between transcription and mRNA metabolism |
| Abstract: | THP1 is a conserved eukaryotic gene whose null mutations confer, in yeast, transcription and genetic instability phenotypes and RNA export defects similar to those of the THO/TREX complex null mutations. In a search for multicopy suppressors of the transcription defect of thp1Δ cells, we identified the poly(A)+ RNA-binding heterogeneous nuclear ribonucleoprotein Nab2p. Multicopy NAB2 also suppressed the RNA export defect of thp1Δ cells. This result suggests a functional relationship between Thp1p and Nab2p. Consistently, the leaky mutation nab2-1 conferred a transcription defect and hyper-recombination phenotype similar to those of thp1Δ, although to a minor degree. Reciprocally, a purified His6-tagged Thp1p fusion bound RNA in vitro. In a different approach, we show by Western analyses that a highly purified Thp1p-Sac3p complex does not contain components of THO/TREX and that sac3A confers a transcription defect and hyper-recombination phenotype identical to those of thp1Δ. mRNA degradation was not affected in thp1Δ mutants, implying that their expression defects are not due to mRNA decay. This indicates that Thp1p-Sac3p is a structural and functional unit. Altogether, our results suggest that Thp1p-Sac3p and Nab2p are functionally related heterogeneous nuclear ribonucleoproteins that define a further link between mRNA metabolism and transcription. |
| Keywords: | unclassified drug; gene mutation; nonhuman; phenotype; metabolism; complex formation; genes; gene expression; protein protein interaction; gene product; transcription, genetic; nuclear proteins; rna; rna-binding proteins; hybrid protein; genetic engineering; messenger rna; protein purification; rna, messenger; eukaryota; recombination, genetic; western blotting; ribonucleoproteins; yeast; saccharomyces cerevisiae proteins; rna metabolism; eukaryote; rna binding; rna transport; rna transcription; null allele; fungal gene; rna degradation; genetic instability; fungal proteins; ribonucleoprotein; heterogeneous-nuclear ribonucleoproteins; nucleocytoplasmic transport proteins; priority journal; article; protein nab2p; protein th1p sac3p; nad2p gene; thp1p gene |
| Journal Title: | Journal of Biological Chemistry |
| Volume: | 278 |
| Issue: | 26 |
| ISSN: | 0021-9258 |
| Publisher: | American Society for Biochemistry and Molecular Biology |
| Date Published: | 2003-06-27 |
| Start Page: | 24225 |
| End Page: | 24232 |
| Language: | English |
| DOI: | 10.1074/jbc.M302900200 |
| PUBMED: | 12702719 |
| PROVIDER: | scopus |
| DOI/URL: | |
| Notes: | Export Date: 12 September 2014 -- Source: Scopus |
