title: Gurken, a TGF-alpha-like protein involved in axis determination in Drosophila, directly binds to the EGF-receptor homolog Egfr.
abstract: The establishment of axial polarity in the Drosophila egg and embryo depends on intercellular communication between two cell types in the ovary, the germline, and the soma. The genes gurken and egfr encode two essential players of this communication pathway. Gurken protein, a TGF-alpha-like molecule, is expressed in the germline, while the EGF-receptor homolog, Egfr, is expressed in the somatic cells of the ovary. Using the yeast two-hybrid system we show here, for the first time, that Gurken protein directly binds to the extracellular domain of Egfr. This direct physical association requires the presence of an intact EGF motif within Gurken protein. Furthermore, we provide evidence that this characteristic motif may be sufficient for interaction with the receptor, at list in vitro. Our results firmly establish Gurken as the germline ligand of Drosophila Egfr.
authors.affiliation: Department of Molecular Genetics of Development, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel.
authors.forename: Anat
authors.initials: A
authors.lastname: Shmueli
authors.forename: Orit
authors.initials: O
authors.lastname: Cohen-Gazala
authors.forename: F Shira
authors.initials: FS
authors.lastname: Neuman-Silberberg
mesh_terms: D000818:Animals; D015153:Blotting, Western; D019521:Body Patterning; D004330:Drosophila / Q000196:embryology; D029721:Drosophila Proteins / Q000737:chemistry / Q000378:metabolism* / Q000502:physiology; D066246:ErbB Receptors / Q000378:metabolism*; D019476:Insect Proteins / Q000737:chemistry / Q000378:metabolism* / Q000502:physiology; D020449:Repetitive Sequences, Amino Acid; D016211:Transforming Growth Factor alpha / Q000378:metabolism; D015291:Transforming Growth Factors / Q000737:chemistry / Q000378:metabolism* / Q000502:physiology; D020798:Two-Hybrid System Techniques; D015003:Yeasts / Q000235:genetics
chemical_list: D029721:Drosophila Proteins; D019476:Insect Proteins; D016211:Transforming Growth Factor alpha; C083730:grk protein, Drosophila; D015291:Transforming Growth Factors; D066246:ErbB Receptors