DEAD-Box RNA helicases in animal gametogenesis

The review summarizes a current knowledge about a role of RNA helicases in the development and maintenance of gamenogenesis in eukaryotes. We focused on three RNA helicase family members-Vasa/DDX4, Belle/DDX3, and Spindle-E/TDRD9-that contain characteristic amino acid sequence motifs (DEAD box) and perform substantial conserved functions in the germinal tissues of various species from Drosophila to human. These enzymes are involved in a broad range of activities associated with the regulation of transcription, splicing, nuclear export and, especially, with translation initiation. Expression of genes required for gametogenesis is regulated mainly at the transcriptional level. RNA helicases are involved in the formation of cytoplasmic ribonucleoprotein (RNP) granules and RNA silencing. A highly conserved central domain is characteristic of DEAD-box RNA helicases and determines their basic biological activity in ATP-dependent unwinding of short RNA duplexes.