Eukaryotic Cell doi:10.1128/EC.00159-07
Copyright (c) 2007, American Society for Microbiology and/or the Listed Authors/Institutions. All Rights Reserved.
A Botrytis cinerea emopamil binding domain protein, required for full virulence, belongs to a eukaryotic superfamily which has expanded in euascomycetes
A. Gioti*,
J. M. Pradier,
E. Fournier,
P. Le Pêcheur,
C. Giraud,
D. Debieu,
J. Bach,
P. Leroux,
and
C. Levis
UMR1290 BIOGER-CPP, I.N.R.A, Route de St - Cyr, 78026 Versailles, France
* To whom correspondence should be addressed. Email:
natassa_g_2000{at}yahoo.com.
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Abstract |
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A previous transcriptomic analysis of 3.032 fungal genes identified the BcPIE3 gene to be up-regulated early in planta (Gioti et al., 2006, J. Mol. Biol. 358: 372-386). In the present study, BcPIE3 was disrupted in order to determine its implication in pathogenicity. BcPIE3 was shown to be a virulence factor, since the 
BcPIE3 mutant was blocked during colonization of tomato and bean leaves, giving lesions reduced by at least 74 %. BcPIE3 shares significant structural similarities to mammalian Emopamil Binding Proteins (EBPs) within the emopamil binding domain (EBD). Mammalian EBPs function as sterol isomerases, but analysis of the sterol content and growth inhibition experiments with the BcPIE3 strain indicated that BcPIE3 is dispensable for ergosterol biosynthesis. The systematic identification of proteins containing the EBD domain in public databases showed that they constitute a protein superfamily present only in eukaryotes. Phylogenetic analysis showed that the ancestral EBD-coding gene was duplicated in the common ancestor of animals and fungi after its split from plants. Finally, we present evidence that the EBP phylogenetic clade of this superfamily has further expanded exclusively in euascomycetes, especially in the B. cinerea genome, which contains four copies.
