Abstract

The fungi Pochonia chlamydosporia and Pochonia rubescens are parasites of nematode eggs and thus are biocontrol agents of nematodes. Proteolytic enzymes such as the S8 proteases VCP1 and P32, secreted during the pathogenesis of nematode eggs, are major virulence factors in these fungi. Recently, expression of these enzymes and of SCP1, a new putative S10 carboxypeptidase, was detected during endophytic colonization of barley roots by these fungi. In our study, we cloned the genomic and mRNA sequences encoding P32 from P. rubescens and SCP1 from P. chlamydosporia. P32 showed a high homology with the serine proteases Pr1A from the entomopathogenic fungus Metarhizium anisopliae and VCP1 from P. chlamydosporia (86% and 76% identity, respectively). However, the catalytic pocket of P32 showed differences in the amino acids of the substrate-recognition sites compared with the catalytic pockets of Pr1A and VCP1 proteases. Phylogenetic analysis of P32 suggests a common ancestor with protease Pr1A. SCP1 displays the characteristic features of a member of the S10 family of serine proteases. Phylogenetic comparisons show that SCP1 and other carboxypeptidases from filamentous fungi have an origin different from that of yeast vacuolar serine carboxypeptidases. Understanding protease genes from nematophagous fungi is crucial for enhancing the biocontrol potential of these organisms.

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Publisher Full Text

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Authors

Larriba E, Martín-Nieto J, Lopez-Llorca LV

Institution

Department of Marine Sciences and Applied Biology, University of Alicante, Spain. eduardo.larriba@ua.es

Source

Canadian journal of microbiology 58:7 2012 Jul pg 815-27

MeSH

Amino Acid Sequence
Animals
Base Sequence
Carboxypeptidases
Cloning, Molecular
Fungal Proteins
Hypocreales
Models, Molecular
Molecular Sequence Data
Phylogeny
Sequence Alignment
Serine Proteases

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

22690687