Interaction of the pelle kinase with the membrane-associated protein tube is required for transduction of the dorsoventral signal in Drosophila embryos.
Within the Drosophila embryo, tube and the protein kinase pelle transduce an intracellular signal generated by the transmembrane receptor Toll. This signal directs import of the rel-related protein dorsal into ventral and ventrolateral nuclei, thereby establishing dorsoventral polarity. We show by immunolocalization that tube protein associates with the plasma membrane during interphase. We also find that tube sequences required for signaling interact with pelle in a yeast two-hybrid assay. We demonstrate that fusion of the pelle catalytic domain to the transmembrane receptor torso is sufficient to induce ventral fates; this activity is independent of Toll or tube. Lastly, we find that fusion of the tube protein to torso also induces ventral fates, but only in the presence of functional pelle. We propose a model wherein tube activates pelle by recruiting it to the plasma membrane, thereby propagating the axis-determining signal.
Galindo
R L
RL
Department of Biochemistry, UT Southwestern, Dallas 75235-9038, USA.
Edwards
D N
DN
Gillespie
S K
SK
Wasserman
S A
SA
D000818:Animals; D001755:Blastocyst / Q000502:physiology*; D002462:Cell Membrane / Q000737:chemistry; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000196:embryology*; D004627:Embryonic Induction; D007091:Image Processing, Computer-Assisted; D007150:Immunohistochemistry; D007301:Insect Hormones / Q000032:analysis / Q000502:physiology; D008562:Membrane Glycoproteins / Q000032:analysis / Q000502:physiology; D018613:Microscopy, Confocal; D017346:Protein Serine-Threonine Kinases / Q000502:physiology*; D011505:Protein-Tyrosine Kinases / Q000032:analysis / Q000502:physiology; D011506:Proteins / Q000502:physiology*; D020794:Receptor Protein-Tyrosine Kinases; D011956:Receptors, Cell Surface / Q000032:analysis / Q000502:physiology; D015398:Signal Transduction; D051193:Toll-Like Receptors
D029721:Drosophila Proteins; D007301:Insect Hormones; D008562:Membrane Glycoproteins; D011506:Proteins; D011956:Receptors, Cell Surface; C068721:Tl protein, Drosophila; D051193:Toll-Like Receptors; C084727:tub protein, Drosophila; C079896:pll protein, Drosophila; D011505:Protein-Tyrosine Kinases; D020794:Receptor Protein-Tyrosine Kinases; C080148:tor protein, Drosophila; D017346:Protein Serine-Threonine Kinases