show("b") signaling."> Characterization of the Drosophila ACK family of non-receptor tyrosine kinases in TGF- signaling. B. Zahedi, X. Xu, N. Harden. Dept Molec Biol & Biochem, Simon Fraser Univ, Burnaby, BC, Canada.

   The ACK family of non-receptor tyrosine kinases have been shown to be effectors for the small GTPase, Cdc42. They are implicated in a range of cell signaling events involving Cdc42, such as cytoskeletal regulation, vesicular transport and integrin signaling. We are characterizing the two Drosophila ACK family members, DACK and DPR2, as part of our study of Cdc42 signaling during Drosophila development. There is evidence that Cdc42 functions in TGF- signaling during the process of dorsal closure. Through the use of wild-type and kinase-dead transgenes, we show that the Drosophila ACKs also function in TGF- signaling during embryogenesis. We have recently generated mutants in the DACK gene and are in the process of screening for mutations in DPR2. We wish to use these mutations to characterize further the role of Drosophila ACKs as effectors for Cdc42 in TGF- signaling and other developmental processes.