Evidence that the cysteine-rich domain of Drosophila Frizzled family receptors is dispensable for transducing Wingless.
Members of the Frizzled family of serpentine transmembrane receptors are required to transduce Wingless/Int (Wnt) signals and contain in their N-terminal regions a conserved Wnt-binding cysteine-rich domain (CRD). Each CRD has specific affinities for particular Wnts, and it is generally believed that signal transduction depends on the strength of this interaction. Here, we report in vivo evidence that the CRD is dispensable for Frizzled family receptors to transduce Wingless (Wg), the primary Wnt signal in Drosophila. Thus, we infer that signal transduction does not require binding of Wg to the CRD, but instead depends on interactions between Wg and other portions of the receptor, or other proteins of the receptor complex.
Chen
Chiann-Mun
CM
Howard Hughes Medical Institute and Department of Genetics and Development, Columbia University College of Physicians and Surgeons, 701 West 168th Street, New York, NY 10032, USA.
Strapps
Walter
W
Tomlinson
Andrew
A
Struhl
Gary
G
D000818:Animals; D001665:Binding Sites; D003545:Cysteine / Q000737:chemistry; D004330:Drosophila / Q000196:embryology / Q000235:genetics / Q000378:metabolism*; D029721:Drosophila Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D051157:Frizzled Receptors; D017344:Genes, Insect; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D017434:Protein Structure, Tertiary; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism*; D043562:Receptors, G-Protein-Coupled / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017981:Receptors, Neurotransmitter / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D051155:Wnt1 Protein
D029721:Drosophila Proteins; D051157:Frizzled Receptors; D008565:Membrane Proteins; D011518:Proto-Oncogene Proteins; D043562:Receptors, G-Protein-Coupled; D017981:Receptors, Neurotransmitter; D051155:Wnt1 Protein; C058784:fz protein, Drosophila; C101703:fz2 protein, Drosophila; C400046:fz3 protein, Drosophila; C074622:wg protein, Drosophila; D003545:Cysteine