Exploring the role of the GW182 protein Gawky during Drosophila early embryogenesis. Jing Li, Andrew Simmonds. Dept. of Cell Biology, University of Alberta, Edmonton, Canada.

   The GW182 protein family is composed of multiple proteins having high percentage of glycine-tryptophan (GW) and troptophan-glycine (WG) repetitive amino acid sequences and a RNA recognition motif on their C-terminal. The Drosophila GW182 single homologue, Gawky (Gw), has been shown to participate in the microRNA (miRNA) repression pathway. A mutation in the gw gene results in an abnormal number of centrosome, missegragation of chromosomes and disrupted microtubule network in the nuclear division cycle at an early stage of embryogenesis (0-2hrs after egg deposition). Our work shows Gw interacts with centrosomal structural protein Centrosomin (CNN) and peri-centriolar protein -tubulin. The endogenous Gw body is adjacent to centrosome in the early embryo. A subset of transcripts related with centrosomal organization function has been found to associated with Gw and conserved miRNA-277 binding sites were predicted residing in the 3 untranslated regions of 4 transcripts. These results suggested that Gw potentially plays an important role during centrosome organization in nuclear mitosis during Drosoophila early embryogenesis.