title: Control of axon-axon attraction by Semaphorin reverse signaling.
abstract: Semaphorin family proteins are well-known axon guidance ligands. Recent studies indicate that certain transmembrane Semaphorins can also function as guidance receptors to mediate axon-axon attraction or repulsion. The mechanisms by which Semaphorin reverse signaling modulates axon-surface affinity, however, remain unknown. In this study, we reveal a novel mechanism underlying upregulation of axon-axon attraction by Semaphorin-1a (Sema1a) reverse signaling in the developing Drosophila visual system. Sema1a promotes the phosphorylation and activation of Moesin (Moe), a member of the ezrin/radixin/moesin family of proteins, and downregulates the level of active Rho1 in photoreceptor axons. We propose that Sema1a reverse signaling activates Moe, which in turn upregulates Fas2-mediated axon-axon attraction by inhibiting Rho1.
authors: McGill Centre for Research in Neuroscience, Department of Neurology and Neurosurgery,Department of Biology, McGill University Health Centre, Montreal, QC, Canada H3G 1A4.
authors: Hsiao-Han
authors: HH
authors: Hsieh
authors: McGill Centre for Research in Neuroscience, Department of Neurology and Neurosurgery.
authors: Wen-Tzu
authors: WT
authors: Chang
authors: McGill Centre for Research in Neuroscience, Department of Neurology and Neurosurgery.
authors: Li
authors: L
authors: Yu
authors: McGill Centre for Research in Neuroscience, Department of Neurology and Neurosurgery,Department of Medicine, and yong.rao@mcgill.ca.
authors: Yong
authors: Y
authors: Rao
mesh_terms: D000818:Animals; D001369:Axons / Q000378:metabolism*; D002448:Cell Adhesion; D015816:Cell Adhesion Molecules, Neuronal / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured; D015536:Down-Regulation; D029721:Drosophila Proteins / Q000378:metabolism; D004331:Drosophila melanogaster / Q000166:cytology / Q000378:metabolism*; D010641:Phenotype; D010766:Phosphorylation; D011485:Protein Binding; D039961:Semaphorins / Q000378:metabolism*; D015398:Signal Transduction; D020741:rho GTP-Binding Proteins / Q000378:metabolism
chemical_list: D015816:Cell Adhesion Molecules, Neuronal; D029721:Drosophila Proteins; D039961:Semaphorins; C051642:fasciclin II; C477531:semaphorin 1a, Drosophila; C511153:Rho1 protein, Drosophila; D020741:rho GTP-Binding Proteins