A C-CBL YEAST 2 HYBRID SCREEN REVEALS INTERACTIONS WITH 14-3-3-ISOFORMS AND CYTOSKELETAL COMPONENTS

The protein product of c-cbl proto oncogene is known to interact with several proteins, including Grb2, Crk and PI3 kinase, and is thought t o regulate signalling by many cell surface receptors. The precise func tion of c-Cbl in these pathways is not clear, although a genetic analy sis in Caenorhabditis elegans suggests that c-Cbl is a negative regula tor of the epidermal growth factor receptor. Here we describe a yeast two hybrid screen performed with c-Cbl in an attempt to further elucid ate its role in signal transduction. The screen identified interaction s involving c-Cbl and two 14-3-3 isoforms, cytokeratin 18, human uncon ventional myosin IC, and a recently identified SH3 domain containing p rotein, SH3 P17. We have used the yeast two hybrid assay to localise r egions of c-Cbl required for its interaction with each of the proteins . Interaction with 14-3-3 is demonstrated in mammalian cell extracts. (C) 1997 Academic Press.