title: Activation of a protease cascade involved in patterning the Drosophila embryo.
abstract: Dorsoventral patterning of the Drosophila embryo is initiated by a ventralizing signal. Production of this signal requires the serine proteases Gastrulation Defective (GD), Snake, and Easter, which genetic studies suggest act sequentially in a cascade that is activated locally in response to a ventral cue provided by the pipe gene. Here, we demonstrate biochemically that GD activates Snake, which in turn activates Easter. We also provide evidence that GD zymogen cleavage is important for triggering this cascade but is not spatially localized by pipe. Our results suggest that a broadly, rather than locally, activated protease cascade produces the ventralizing signal, so a distinct downstream step in this cascade must be spatially regulated to restrict signaling to the ventral side of the embryo.
authors: Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06520, USA.
authors: E K
authors: EK
authors: LeMosy
authors: Y Q
authors: YQ
authors: Tan
authors: C
authors: C
authors: Hashimoto
mesh_terms: D000818:Animals; D015153:Blotting, Western; D019521:Body Patterning; D002460:Cell Line; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000196:embryology* / Q000201:enzymology / Q000235:genetics; D004625:Embryo, Nonmammalian / Q000002:abnormalities / Q000196:embryology / Q000201:enzymology* / Q000378:metabolism; D004789:Enzyme Activation; D004792:Enzyme Precursors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D005775:Gastrula; D019476:Insect Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008970:Molecular Weight; D009865:Oocytes / Q000378:metabolism; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D017384:Sequence Deletion; D012697:Serine Endopeptidases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D015238:Sulfotransferases / Q000378:metabolism
chemical_list: D029721:Drosophila Proteins; D004792:Enzyme Precursors; D019476:Insect Proteins; D010446:Peptide Fragments; D015238:Sulfotransferases; C115847:pip protein, Drosophila; D012697:Serine Endopeptidases; C078099:ea protein, Drosophila; C115869:ndl protein, Drosophila; C081508:snk protein, Drosophila