Intracellular trafficking by Star regulates cleavage of the Drosophila EGF receptor ligand Spitz.

ABSTRACT: Spitz (Spi) is a TGFalpha homolog that is a cardinal ligand for the Drosophila EGF receptor throughout development. Cleavage of the ubiquitously expressed transmembrane form of Spi (mSpi) precedes EGF receptor activation. We show that the Star and Rhomboid (Rho) proteins are necessary for Spi cleavage in Drosophila cells. Complexes between the Spi and Star proteins, as well as between the Star and Rho proteins were identified, but no Spi-Star-Rho triple complex was detected. This observation suggests a sequential activity of Star and Rho in mSpi processing. The interactions between Spi and Star regulate the intracellular trafficking of Spi. The Spi precursor is retained in the periphery of the nucleus. Coexpression of Star promotes translocation of Spi to a compartment where Rho is present

SUBMITTER: Tsruya R 

PROVIDER: S-EPMC155325 | biostudies-literature | 2002 Jan

REPOSITORIES: biostudies-literature