Identification and characterization of RNA sequences to which human PUMILIO-2 (PUM2) and deleted in Azoospermia-like (DAZL) bind

Members of the Pumilio and DAZL family of RNA binding proteins are required for germ cell development in Drosophila, Xenopus, and Caenorhabditis elegans. Here, we report identification and characterization of RNA sequences to which PUM2 and DAZL bind. We established that human PUM2 specifically recognized the Drosophila Pumilio RNA target (the NRE or Nanos regulator element sequence); single nucleotide changes in the NRE abolished PUM2 binding. Then, we used coimmunoprecipitation to isolate human transcripts specifically bound by PUM2 and DAZL and subsequently identified those that contain NRE-like sequence elements. We confirmed that the interacting proteins, PUM2 and DAZL, are capable of binding the same RNA target and further characterized mRNA sequences bound by both proteins in the 3′UTR of human SDAD1 mRNA. Taken together, the results define sequences to which these germ cell-specific RNA binding proteins may bind to promote germ cell development.