Activation of Snake in a serine protease cascade that defines the dorsoventral axis is atypical and pipe-independent in Drosophila embryos.
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.
Steen
Pamela W
PW
Department of Cellular Biology and Anatomy, Medical College of Georgia, 1120 15th St., CB1101, Augusta, GA 30912, USA.
Tian
Sufang
S
Tully
Sarah E
SE
Cravatt
Benjamin F
BF
LeMosy
Ellen K
EK
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*
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