@article {125,
	title = {Immune challenge induces N-terminal cleavage of the Drosophila serpin Necrotic.},
	journal = {Insect biochemistry and molecular biology},
	volume = {36},
	year = {2006},
	month = {2006 Jan},
	pages = {37-46},
	abstract = {The Drosophila Necrotic protein is a serine proteinase inhibitor, which regulates the Toll-mediated innate immune response. Necrotic specifically inhibits an extracellular serine proteinase cascade leading to activation of the Toll ligand, Sp{\"a}tzle. Necrotic carries a polyglutamine extension amino-terminal to the core serpin structure. We show here that cleavage of this N-terminal extension occurs following immune challenge. This modification is blocked in PGRP-SA(semmelweiss) mutants after Gram-positive bacterial challenge and in persephone mutants after fungal or Gram-positive bacterial challenge, indicating that activation of either of the Toll pathway upstream branches induces N-terminal cleavage of the serpin. The absolute requirement of persephone gene product for this cleavage indicates that Gram-positive bacteria activate a redundant set of proteinases upstream of Toll. Both full-length Necrotic and the core serpin are active inhibitors of a range of serine proteinases: the highest affinity being for cathepsin G and elastases. We found a 13-fold increase in the specificity of the core serpin over that of full-length Necrotic for one of the tested proteinases (porcine pancreatic elastase). This finding indicates that cleavage of the Necrotic amino-terminal extension might modulate Toll activation following the initial immune response.},
	keywords = {Animals, Drosophila melanogaster, Drosophila Proteins, Gene Expression Regulation, Protein Conformation, Serpins, Signal Transduction},
	issn = {0965-1748},
	doi = {10.1016/j.ibmb.2005.10.004},
	author = {Pelte, Nad{\`e}ge and Robertson, Andrew S and Zou, Zhen and Belorgey, Didier and Dafforn, Timothy R and Jiang, Haobo and Lomas, David and Reichhart, Jean-Marc and Gubb, David}
}
