Binding of ATP to UAP56 is necessary for mRNA export
| Autor: | Jean M. Underwood, Stefan Wagner, Elvira Huerta, Jeffrey A. Nickerson, Krishna P. Kota |
|---|---|
| Rok vydání: | 2008 |
| Předmět: |
Cytoplasm
RNA Splicing Mitosis RNA Transport DEAD-box RNA Helicases Adenosine Triphosphate Nuclear Matrix-Associated Proteins Transcription (biology) Humans Point Mutation RNA Messenger Nuclear protein Messenger RNA biology Lysine Point mutation RNA-Binding Proteins Helicase Antigens Nuclear Cell Biology Molecular biology Cell biology RNA splicing biology.protein Exon junction complex Mutant Proteins Asparagine Fluorescence Recovery After Photobleaching HeLa Cells Protein Binding |
| Zdroj: | Journal of Cell Science. 121:1526-1537 |
| ISSN: | 1477-9137 0021-9533 |
| DOI: | 10.1242/jcs.021055 |
| Popis: | The major-histocompatibility-complex protein UAP56 (BAT1) is a DEAD-box helicase that is deposited on mRNA during splicing. UAP56 is retained on spliced mRNA in an exon junction complex (EJC) or, alternatively, with the TREX complex at the 5′ end, where it might facilitate the export of the spliced mRNA to the cytoplasm. Using confocal microscopy, UAP56 was found to be concentrated in RNA-splicing speckled domains of nuclei but was also enriched in adjacent nuclear regions, sites at which most mRNA transcription and splicing occur. At speckled domains, UAP56 was in complexes with the RNA-splicing and -export protein SRm160, and, as measured by FRAP, was in a dynamic binding equilibrium. The application of an in vitro FRAP assay, in which fluorescent nuclear proteins are photobleached in digitonin-extracted cells, revealed that the equilibrium binding of UAP56 in complexes at speckled domains was directly regulated by ATP binding. This was confirmed using a point mutant of UAP56 that did not bind ATP. Point mutation of UAP56 to eliminate ATP binding did not affect RNA splicing, but strongly inhibited the export of mRNA to the cytoplasm. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|