title: Developmental regulation of membrane protein sorting in Drosophila embryos.
abstract: We have examined the process of membrane protein targeting in the polarized cells of the developing Drosophila melanogaster embryo. Human placental alkaline phosphatase (PLAP) is a glycosylphosphatidyl inositol-linked protein that accumulates at the apical membranes of mammalian epithelial cells. A chimeric construct composed of the transmembrane and cytosolic portions of the vesicular stomatitis virus G protein coupled to the ectodomain of PLAP, termed PLAPG, has been found to behave as a basolateral protein (D. A. Brown, B. Crise, and J. K. Rose. Science Wash. DC 232: 34-47, 1989). The subcellular distributions of these proteins were examined in the epithelial and neuronal tissues of transgenic Drosophila embryos. In the surface ectoderm, both PLAP and PLAPG were restricted to the basolateral membranes throughout development. Internal epithelia derived from the surface ectoderm accumulated PLAP at their apical surfaces, whereas PLAPG retained its basolateral distribution. The redistribution of PLAP from the basolateral to the apical plasma membrane was found to be coincident with the invagination of the surface epithelium to form internal structures, suggesting that the sorting pathways that function in the epithelium of the Drosophila embryo are developmentally regulated.
authors.affiliation: Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut 06510, USA.
authors.forename: M J
authors.initials: MJ
authors.lastname: Shiel
authors.forename: M J
authors.initials: MJ
authors.lastname: Caplan
mesh_terms: D000469:Alkaline Phosphatase / Q000235:genetics / Q000378:metabolism; D000818:Animals; D002462:Cell Membrane / Q000378:metabolism; D002678:Chimera; D004331:Drosophila melanogaster / Q000196:embryology* / Q000235:genetics; D004475:Ectoderm / Q000378:metabolism; D004625:Embryo, Nonmammalian / Q000502:physiology*; D019204:GTP-Binding Proteins / Q000235:genetics; D008040:Genetic Linkage; D017261:Glycosylphosphatidylinositols / Q000235:genetics / Q000378:metabolism; D006801:Humans; D008565:Membrane Proteins / Q000502:physiology*; D009154:Mutation; D009420:Nervous System / Q000196:embryology; D010920:Placenta / Q000201:enzymology; D014721:Vesicular stomatitis Indiana virus / Q000378:metabolism; D014764:Viral Proteins / Q000235:genetics
chemical_list: D017261:Glycosylphosphatidylinositols; D008565:Membrane Proteins; D014764:Viral Proteins; D000469:Alkaline Phosphatase; D019204:GTP-Binding Proteins