DEAD Box Polypeptide 19B (DDX19B)

is recruited to the cytoplasmic fibrils of the nuclear pore complex, where it participates in the export of mRNA from the nucleus. Multiple alternatively spliced transcript variants encoding different isoforms have been found for this gene.deduced 479-amino acid protein is 94% and 46% identical to the mouse and yeast sequences, respectively. Western blot analysis showed that recombinant and native proteins have an identical molecular mass of approximately 56 kD. Functional analysis indicated that DDX19 exhibits RNA-dependent ATPase and ATP-dependent RNA-unwinding activities. Fluorescence microscopy demonstrated cytoplasmic expression of DDX19, with a fraction localized at the nuclear rim.