ATP-dependent RNA helicase involved in pre-mRNA splicing. Required for the export of mRNA out of the nucleus. In addition to ssRNA and dsRNA, binds dsDNA, but not ssDNA. ATP + H2O = ADP + H(+) + phosphate Interacts with ALY2 and MOS11. Localizes predominantly to euchromatic regions of the nucleoplasm. The Q motif is unique to and characteristic of the DEAD box family of RNA helicases and controls ATP binding and hydrolysis. May be due to intron retention. May be due to intron retention. Belongs to the DEAD box helicase family. DECD subfamily.