First published online April 23, 2008
Journal of Cell Science 121, 905e (2008)
© The Company of Biologists Limited
ATP lends UAP56 a helping hand
RNA splicing is coupled to RNA export from the nucleus to the cytoplasm. The export of most mRNAs requires the DExD/H-box family RNA helicase UAP56, which is deposited on mRNA during splicing. On page 1526, Jeffrey A. Nickerson and colleagues describe the immunofluorescent characterization of UAP56, and its subnuclear targeting and molecular dynamics. They show that UAP56 is most concentrated in the RNA-splicing speckled domains in nuclei, but is also enriched in the region around the speckled domain, where most mRNA transcription and splicing occur. At these domains, demonstrate the authors using an in vitro FRAP approach, UAP56 is assembled into complexes in an ATP-dependent manner. Moreover, FRET analysis shows that UAP56 and the RNA-splicing and -export factor SRm160 inhabit the same complex at the RNA-splicing speckled domains. A specific point mutant of UAP56 that does not bind to ATP does not affect the ATP-dependent binding of SRm160 at the speckled domains. RNA splicing was unaffected using this point mutant, but RNA export to the cytoplasm was inhibited through a dominant-negative mechanism – this highlights the central role of ATP binding to UAP56 in the assembly of the mRNA-export complex.
Related articles in JCS:
- Binding of ATP to UAP56 is necessary for mRNA export
- Krishna P. Kota, Stefan R. Wagner, Elvira Huerta, Jean M. Underwood, and Jeffrey A. Nickerson
JCS 2008 121: 1526-1537.
[Abstract]
[Full Text]
