Activation of the Drosophila EGF receptor requires the transmembrane TGF-α-like ligand Spitz. Recent studies have shed new light on the role of two transmembrane proteins, Star and Rhomboid, in the presentation and subsequent proteolytic processing of Spitz.
Klämbt, C. (2000, May 1). EGF receptor signalling: The importance of presentation. Current Biology. Current Biology Ltd. https://doi.org/10.1016/S0960-9822(00)00485-1