Reconstitution of Torso signaling in cultured cells suggests a role for both Trunk and Torso-like in receptor activation

摘要: Formation of the Drosophila embryonic termini is controlled by localized activation receptor tyrosine kinase Torso. Both Torso and Torso9s presumed ligand, Trunk, are expressed uniformly in early embryo. Polar requires Torso-like, which follicle cells adjacent to ends developing oocyte. We find that at high levels cultured activated individual application Torso-like or another known Prothoracicotropic Hormone. In addition assays downstream signaling activity, dimerization was detected using bimolecular fluorescence complementation. Trunk were active when co-transfected with presented Torso-expressing conditioned medium. also taken up from medium specifically expressing At low Torso, similar those present embryo, alone ineffective but acted synergistically stimulate signaling. Our results suggest interacts both cooperate mediate