title: Activation of Snake in a serine protease cascade that defines the dorsoventral axis is atypical and pipe-independent in Drosophila embryos.
abstract: During Drosophila embryogenesis, establishment of ventral and lateral cell fates requires spatial regulation of an extracellular serine protease cascade composed of Nudel, Gastrulation Defective (GD), Snake, and Easter. Pipe, a sulfotransferase expressed ventrally during oogenesis, sulfates secreted targets that somehow confer positive spatial input to this cascade. Nudel and GD activation are pipe-independent, while Easter activation requires pipe. The effect of pipe on Snake activation has been unknown. Here we show that Snake activation is cascade-dependent but pipe-independent. These findings support a conclusion that Snake's activation of Easter is the first spatially regulated step in the dorsoventral protease cascade.
authors.affiliation: Department of Cellular Biology and Anatomy, Medical College of Georgia, 1120 15th St., CB1101, Augusta, GA 30912, USA.
authors.forename: Pamela W
authors.initials: PW
authors.lastname: Steen
authors.forename: Sufang
authors.initials: S
authors.lastname: Tian
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Tully
authors.forename: Benjamin F
authors.initials: BF
authors.lastname: Cravatt
authors.forename: Ellen K
authors.initials: EK
authors.lastname: LeMosy
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D019521:Body Patterning; D004330:Drosophila / Q000196:embryology* / Q000235:genetics / Q000378:metabolism*; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004789:Enzyme Activation; D005260:Female; D017344:Genes, Insect; D009154:Mutation; D012697:Serine Endopeptidases / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D015238:Sulfotransferases / Q000235:genetics / Q000378:metabolism*
chemical_list: D029721:Drosophila Proteins; D015238:Sulfotransferases; C115847:pip protein, Drosophila; D012697:Serine Endopeptidases; C078099:ea protein, Drosophila; C440488:gd protein, Drosophila; C115869:ndl protein, Drosophila; C081508:snk protein, Drosophila