A Drosophila Protein-tyrosine Phosphatase Associates with an Adapter Protein Required for Axonal Guidance

摘要: We have used the yeast two-hybrid system to isolate a novel Drosophila adapter protein, which interacts with protein-tyrosine phosphatase (PTP) dPTP61F. Absence of this protein in causes mutant photoreceptor axon phenotype dreadlocks (dock) (Garrity, P. A., Rao, Y., Salecker, I., and Zipursky, S. L. (1996) Cell 85, 639-650). Dock is similar mammalian oncoprotein Nck contains three Src homology 3 (SH3) domains one 2 (SH2) domain. The interaction dPTP61F was confirmed vivo by immune precipitation experiments. A sequence containing five PXXP motifs from non-catalytic domain PTP sufficient for Dock. This suggests that binding mediated or more SH3 Immune precipitations also co-precipitate two tyrosine-phosphorylated proteins having molecular masses 190 145 kDa. Interactions between these are likely SH2 These findings identify potential signal-transducing partners propose role unidentified phosphoproteins axonal guidance.