Isolation and characterization of Dek, a Drosophila eph receptor protein tyrosine kinase.

We have isolated a Drosophila receptor protein tyrosine kinase (RTK) of the Eph subfamily. Dek, for Drosophila Eph kinase, possesses all the domains characteristic of the Eph subfamily of RTKs and is equally similar in sequence to both the EphA and the EphB subclasses. Antibody staining and promoter fusions to axon-targeted reporters reveal that Dek is expressed by a large subset of developing embryonic interneurons and is targeted to their axons and growth cones at the time of axon pathfinding. Dek is also expressed by photoreceptor cells of third-instar larvae as they project axons into the optic brain lobe. Misexpression and overexpression of full-length Dek or kinase-inactive Dek do not grossly affect axon pathfinding.