Spatially dependent activation of the patterning protease, Easter.
The dorsoventral axis of the Drosophila embryo is established by the activating cleavage of a signaling ligand by a serine protease, Easter, only on the ventral side of the embryo. Easter is the final protease in a serine protease cascade in which initial reaction steps appear not to be ventrally restricted, but where Easter activity is promoted ventrally through the action of a spatial cue at an unknown step in the pathway. Here, biochemical studies demonstrate that this spatial control occurs at or above the level of Easter zymogen activation, rather than through direct promotion of Easter's catalytic activity against the signaling ligand.
LeMosy
Ellen K
EK
Department of Cellular Biology and Anatomy, Medical College of Georgia, 1120 15th St., CB2915, Augusta, GA 30912, USA. elemosy@mail.mcg.edu
D000818:Animals; D002970:Cleavage Stage, Ovum / Q000201:enzymology*; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster; D004625:Embryo, Nonmammalian / Q000201:enzymology; D004789:Enzyme Activation / Q000235:genetics; D004792:Enzyme Precursors / Q000235:genetics / Q000378:metabolism*; D008024:Ligands; D012697:Serine Endopeptidases / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology*
D029721:Drosophila Proteins; D004792:Enzyme Precursors; D008024:Ligands; D012697:Serine Endopeptidases; C078099:ea protein, Drosophila