Activation of a Protease Cascade Involved in Patterning the Drosophila Embryo

• Published in: Proceedings of the National Academy of Sciences - PNAS 2001-04, Vol.98 (9), p.5055-5060
• Main Authors: LeMosy, Ellen K., Tan, Yue-Qing, Hashimoto, Carl
• Format: Article
• Language: English
• Subjects: Animals; Antibodies; Biochemistry; Biological Sciences; Blotting, Western; Body Patterning; Cell Line; Drosophila; Drosophila melanogaster - embryology; Drosophila melanogaster - enzymology; Drosophila melanogaster - genetics; Drosophila Proteins; Easter; Easter protein; Embryo, Nonmammalian - abnormalities; Embryo, Nonmammalian - embryology; Embryo, Nonmammalian - enzymology; Embryo, Nonmammalian - metabolism; Embryogenesis; Embryos; Enzyme Activation; Enzyme Precursors - chemistry; Enzyme Precursors - genetics; Enzyme Precursors - metabolism; Gastrula; Gastrulation defective protein; Gene expression regulation; Insect Proteins - chemistry; Insect Proteins - genetics; Insect Proteins - metabolism; Ligands; Molecular Weight; Oocytes - metabolism; Ovaries; Peptide Fragments - chemistry; Peptide Fragments - metabolism; pipe gene; Protein Processing, Post-Translational; Sequence Deletion; Serine Endopeptidases - chemistry; Serine Endopeptidases - genetics; Serine Endopeptidases - metabolism; Signal Transduction; Snake protein; Snakes; Sulfotransferases - metabolism; Tolls; Zymogens
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.081026598

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.