Search National Agricultural Library Digital Collections

NALDC Record Details:

Identification of a chitinase-modifying protein from Fusarium verticillioides: Truncation of a host resistance protein by a fungalysin metalloprotease

Permanent URL:
http://handle.nal.usda.gov/10113/53774
File:
Download [PDF File]
Abstract:
Chitinase-modifying proteins (cmps) are proteases secreted by fungal pathogens that truncate the plant class IV chitinases ChitA and ChitB during maize ear rot. cmp activity has been characterized for Bipolaris zeicola and Stenocarpella maydis, but the identities of the proteases are not known. Here, we report that cmps are secreted by multiple species from the genus Fusarium, that cmp from Fusarium verticillioides (Fv-cmp) is a fungalysin metalloprotease, and that it cleaves within a sequence that is conserved in class IV chitinases. Protein extracts from Fusarium cultures were found to truncate ChitA and ChitB in vitro. Based on this activity, Fv-cmp was purified from F. verticillioides. N-terminal sequencing of truncated ChitA and MALDI-TOF-MS analysis of reaction products showed that Fv-cmp is an endoprotease that cleaves a peptide bond on the C-terminal side of the lectin domain. The N-terminal sequence of purified Fv-cmp was determined and compared with a set of predicted proteins, resulting in its identification as a zinc metalloprotease of the fungalysin family. Recombinant Fv-cmp also truncated ChitA, confirming its identity, but had reduced activity, suggesting that the recombinant protease did not mature efficiently from its propeptide-containing precursor. This is the first report of a fungalysin that targets a nonstructural host protein and the first to implicate this class of virulence-related proteases in plant disease.
Author(s):
Naumann, Todd A. , Wicklow, Donald T. , Price, Neil P.J.
Subject(s):
Fusarium , Gibberella fujikuroi , amino acid sequences , chitinase , corn ears , ear rot , metalloproteinases , pathogenesis , plant pathogenic fungi , proteins , proteolysis
Note:
Includes references
Source:
Journal of biological chemistry 2011 Oct. 14, v. 286, no. 41
Language:
English
Year:
2011
Collection:
Journal Articles, USDA Authors, Peer-Reviewed
Rights:
Works produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. The content of this document is not copyrighted.