Recent advances in plant cell wall proteomics

Abstract

The plant extracellular matrix contains typical polysaccharides such as cellulose, hemicelluloses, and pectins that interact to form dense interwoven networks. Plant cell walls play crucial roles during development and constitute the first barrier of defense against invading pathogens. Cell wall proteomics has greatly contributed to the description of the protein content of a compartment specific to plants. Around 400 cell wall proteins (CWPs) of Arabidopsis, representing about one fourth of its estimated cell wall proteome, have been described. The main points to note are that: (i) the diversity of enzymes acting on polysaccharides suggests a great plasticity of cell walls; (ii) CWPs such as proteases, polysaccharide hydrolytic enzymes, and lipases may contribute to the generation of signals; (iii) proteins of unknown functions were identified, suggesting new roles for cell walls. Recently, the characterization of PTMs such as N- and O-glycosylations improved our knowledge of CWP structure. The presence of many glycoside hydrolases and proteases suggests a complex regulation of CWPs involving various types of post-translational events. The first 3-D structures to be resolved gave clues about the interactions between CWPs, or between CWPs and polysaccharides. Future work should include: extracting and identifying CWPs still recalcitrant to proteomics, describing the cell wall interactome, improving quantification, and unraveling the roles of each of the CWPs.

Nicotiana tabacumprotoplasts secretome can evidence relations among regulatory elements of exocytosis mechanisms

“…The extraction of cell wall proteins from protoplasts is a particular task since the proteins may be free in the incubation medium or are embedded in a polysaccharide matrix where they are retained by various interactions. 3 We have chosen to address our investigation to the proteome of incubation medium only, to have a reproducible, although limited proteic profile. A simple profile was easier to analyze in a comparative study of the effect of overexpression and negative competition of 4 different regulatory proteins: SYP121, SYP122, SNAP33 and Rab11.…”

“…Proteomics of the various plant cell walls have been reported and are under investigation, but several difficulties arise about pattern complexity and reproducibility. 3 One problem derives from the interactions between proteins and the matrix polysaccharides that influence CWPs solubilization and conditionate their recovery in An alternative study involving proteome analysis of the 24 h Nicotiana tabacum protoplast culture medium was performed with the aim to confirm relations among regulatory elements of exocytotic processes. Protoplasts present many convenient features to study cellular processes during transient overexpression or suppression of specific gene's products.…”

Straying off the Highway: Trafficking of Secreted Plant Proteins and Complexity in the Plant Cell Wall Proteome

“…Analyses of protein populations from the walls of many plant organs and tissues have been reported (for review, see Lee et al, 2004;Jamet et al, 2006Jamet et al, , 2008a, together with detailed methodologies to optimize extraction (Feiz et al, 2006;Watson and Sumner, 2007;Jamet et al, 2008b). These have resulted in catalogs of proteins whose identity matches known functions associated with wall-related processes, such as polysaccharide modification, defense, and signaling, as well as many with unknown functions.…”

Alteration in the gene expression ofGlehnia littoralisseedlings exposed to culture filtrate ofPenicillium citrinumKACC43900

“…A highly expressed protein, ODC and uniquely expressed beta-expansin, EXPB4 were other important GAP implicated separately in the two growth process, the cell proliferation, and cell expansion. ODC is associated with plant cell multiplication (Cohen et al 1982) and polyamine biosynthesis (Alcazar et al 2010), while the betaexpansin EXPB4 is known to be the key regulators of cell expansion during growth (Lin et al 2005), by modifying the cell wall (Jamet et al 2008). Previous studies reported an increased activity and expression of expansions during GAs induced elongation in deep water rice (Choe & Cosgrove 2004), indicating the presence of GAs in the fungal CF.…”