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 (By similarity). Isoform 1 is expressed in germ cells. Isoform 2 is highly expressed in Leydig cells and weakly expressed in the pituitary and hypothalamus. Isoform 3 is weakly expressed only in germ cells. Expressed in pubertal and adult animals but not in immature animals. By gonadotropin in Leydig cells. Inhibited by flutamine. Phosphorylated on threonine residues. The phosphorylated form is found in the cytoplasm but not in the nucleus. May start at Met-200 rather than Met-190. Belongs to the DEAD box helicase family.