The unique architecture and function of cellulose-interacting proteins in oomycetes revealed by genomic and structural analyses

BMC Genomics

Research Article

Roland Barriot¹  Elodie Gaulin²  Arnaud Bottin²  Mathieu Larroque²  Bernard Dumas²  Pierre Rougé³  Annick Barre³ 

[1] Université de Toulouse, UPS, Laboratoire de Microbiologie et Génétique Moléculaire, F-31000, Toulouse, France;Centre National de la Recherche Scientifique; LMGM, F-31000, Toulouse, France;Université de Toulouse, UPS, Laboratoire de Recherche en Sciences Végétales, 24 chemin de Borde Rouge, BP42617F-31326, Auzeville, Castanet-Tolosan, France;CNRS, Laboratoire de Recherche en Sciences Végétales, 24 chemin de Borde Rouge, BP42617, F-31326, Auzeville, Castanet-Tolosan, France;Université de Toulouse, UPS, Laboratoire de Recherche en Sciences Végétales, 24 chemin de Borde Rouge, BP42617F-31326, Auzeville, Castanet-Tolosan, France;CNRS, Laboratoire de Recherche en Sciences Végétales, 24 chemin de Borde Rouge, BP42617, F-31326, Auzeville, Castanet-Tolosan, France;Université de Toulouse, UPS, Laboratoire PHARMA-DEV IRD UMR 152, 35 Chemin des Maraîchers, 31400, Toulouse, France;

关键词: Cellulose;    Oomycete;    Lectin;    Immunity;    Plant;    Adhesion;    Fungi;   

DOI  :  10.1186/1471-2164-13-605

 received in 2012-06-07, accepted in 2012-10-25,  发布年份 2012

来源: Springer

【 摘 要 】

BackgroundOomycetes are fungal-like microorganisms evolutionary distinct from true fungi, belonging to the Stramenopile lineage and comprising major plant pathogens. Both oomycetes and fungi express proteins able to interact with cellulose, a major component of plant and oomycete cell walls, through the presence of carbohydrate-binding module belonging to the family 1 (CBM1). Fungal CBM1-containing proteins were implicated in cellulose degradation whereas in oomycetes, the Cellulose Binding Elicitor Lectin (CBEL), a well-characterized CBM1-protein from Phytophthora parasitica, was implicated in cell wall integrity, adhesion to cellulosic substrates and induction of plant immunity.ResultsTo extend our knowledge on CBM1-containing proteins in oomycetes, we have conducted a comprehensive analysis on 60 fungi and 7 oomycetes genomes leading to the identification of 518 CBM1-containing proteins. In plant-interacting microorganisms, the larger number of CBM1-protein coding genes is expressed by necrotroph and hemibiotrophic pathogens, whereas a strong reduction of these genes is observed in symbionts and biotrophs. In fungi, more than 70% of CBM1-containing proteins correspond to enzymatic proteins in which CBM1 is associated with a catalytic unit involved in cellulose degradation. In oomycetes more than 90% of proteins are similar to CBEL in which CBM1 is associated with a non-catalytic PAN/Apple domain, known to interact with specific carbohydrates or proteins. Distinct Stramenopile genomes like diatoms and brown algae are devoid of CBM1 coding genes. A CBM1-PAN/Apple association 3D structural modeling was built allowing the identification of amino acid residues interacting with cellulose and suggesting the putative interaction of the PAN/Apple domain with another type of glucan. By Surface Plasmon Resonance experiments, we showed that CBEL binds to glycoproteins through galactose or N-acetyl-galactosamine motifs.ConclusionsThis study provides insight into the evolution and biological roles of CBM1-containing proteins from oomycetes. We show that while CBM1s from fungi and oomycetes are similar, they team up with different protein domains, either in proteins implicated in the degradation of plant cell wall components in the case of fungi or in proteins involved in adhesion to polysaccharidic substrates in the case of oomycetes. This work highlighted the unique role and evolution of CBM1 proteins in oomycete among the Stramenopile lineage.

【 授权许可】

Unknown   
© Larroque et al.; licensee BioMed Central Ltd. 2012. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.