ATP-dependent RNA helicase. Required for mRNA export and translation regulation during spermatid development (By similarity). ATP + H2O = ADP + H(+) + phosphate Detected in both cytoplasm and nucleus of testicular cells. Also detected in chromatoid bodies of round spermatids. Phosphorylated on threonine residues. The phosphorylated form is found in the cytoplasm but not in the nucleus (By similarity). Belongs to the DEAD box helicase family.