title: Neurexin IV and Wrapper interactions mediate Drosophila midline glial migration and axonal ensheathment.
abstract: Glia play crucial roles in ensheathing axons, a process that requires an intricate series of glia-neuron interactions. The membrane-anchored protein Wrapper is present in Drosophila midline glia and is required for ensheathment of commissural axons. By contrast, Neurexin IV is present on the membranes of neurons and commissural axons, and is highly concentrated at their interfaces with midline glia. Analysis of Neurexin IV and wrapper mutant embryos revealed identical defects in glial migration, ensheathment and glial subdivision of the commissures. Mutant and misexpression experiments indicated that Neurexin IV membrane localization is dependent on interactions with Wrapper. Cell culture aggregation assays and biochemical experiments demonstrated the ability of Neurexin IV to promote cell adhesion by binding to Wrapper. These results show that neuronal-expressed Neurexin IV and midline glial-expressed Wrapper act as heterophilic adhesion molecules that mediate multiple cellular events involved in glia-neuron interactions.
authors.affiliation: Department of Biochemistry and Biophysics, The University of North Carolina, Chapel Hill, NC 27599, USA.
authors.forename: Scott R
authors.initials: SR
authors.lastname: Wheeler
authors.forename: Swati
authors.initials: S
authors.lastname: Banerjee
authors.forename: Kevin
authors.initials: K
authors.lastname: Blauth
authors.forename: Stephen L
authors.initials: SL
authors.lastname: Rogers
authors.forename: Manzoor A
authors.initials: MA
authors.lastname: Bhat
authors.forename: Stephen T
authors.initials: ST
authors.lastname: Crews
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D001369:Axons / Q000648:ultrastructure; D001483:Base Sequence; D002448:Cell Adhesion / Q000235:genetics / Q000502:physiology; D015816:Cell Adhesion Molecules, Neuronal / Q000235:genetics / Q000378:metabolism*; D002465:Cell Movement / Q000235:genetics / Q000502:physiology; D017931:DNA Primers / Q000235:genetics; D004330:Drosophila / Q000196:embryology* / Q000235:genetics / Q000378:metabolism*; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D017344:Genes, Insect; D017403:In Situ Hybridization; D009154:Mutation; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D055495:Neurogenesis / Q000235:genetics / Q000502:physiology; D009457:Neuroglia / Q000502:physiology*; D009474:Neurons / Q000378:metabolism; D010641:Phenotype; D011485:Protein Binding; D012313:RNA / Q000235:genetics / Q000378:metabolism
chemical_list: D015816:Cell Adhesion Molecules, Neuronal; D017931:DNA Primers; D029721:Drosophila Proteins; D009419:Nerve Tissue Proteins; C491321:Nrx protein, Drosophila; C116202:wrapper protein, Drosophila; D012313:RNA