Identification and characterization of DSNX6, a sorting nexin that interacts with 14-3-3. S. Grammenoudi¹, T.C. Varonos¹, S. Acevedo², E.M.C. Skoulakis^1,2. 1) Institute of Molecular Biology and Genetics, B.S.R.C. "Al. Fleming", Vari, Attiki, Greece; 2) Department of Biology, Faculty of Neuroscience, Texas A & M University, College Station, TX 77843.

   The 14-3-3s are a family of evolutionary conserved proteins in all eukaryotes. They are small, acidic, cytosolic, abundant in brain proteins that interact with a wide range of signaling molecules, including kinases, phosphatases and transmembrane receptors. They have been implicated in the regulation of diverse biological processes such as development and function of the nervous system, cell cycle control and viral pathogenesis. To elucidate the function of 14-3-3s in the adult nervous system we attempted identification of proteins in adult Drosophila brain that interact with LEONARDO (14-3-3z) through a two-hybrid system. Here, we present characterization of a novel 14-3-3 interacting protein DSNX6. The dsnx6 gene encodes a sorting nexin homologous to human sorting nexin 6. Sorting nexins are a recently identified group of cytoplasmic and membrane-associated proteins characterized by the presence of a phospholipid-binding motif, the PX (phox homology) domain. They bind to specific phospholipids, various receptors and signaling molecules indicating a role in membrane trafficking and protein sorting through protein-protein complex formation. So far, more than 25 human proteins have been classified as sorting nexins, mainly due to the presence of a PX-domain, as sorting nexin functional studies are still in their infancy. DSNX6 appears to interact with and co-localise with LEONARDO and based on its expression pattern is likely an essential gene. We present the spatial and temporal expression pattern of DSNX6, as well as molecular analysis data.