The Cell Wall PAC (Proline-Rich, Arabinogalactan Proteins, Conserved Cysteines) Domain-Proteins Are Conserved in the Green Lineage

Abstract

Plant cell wall proteins play major roles during plant development and in response to environmental cues. A bioinformatic search for functional domains has allowed identifying the PAC domain (Proline-rich, Arabinogalactan proteins, conserved Cysteines) in several proteins (PDPs) identified in cell wall proteomes. This domain is assumed to interact with pectic polysaccharides and O-glycans and to contribute to non-covalent molecular scaffolds facilitating the remodeling of polysaccharidic networks during rapid cell expansion. In this work, the characteristics of the PAC domain are described in detail, including six conserved Cys residues, their spacing, and the predicted secondary structures. Modeling has been performed based on the crystal structure of a Plantago lanceolata PAC domain. The presence of β-sheets is assumed to ensure the correct folding of the PAC domain as a β-barrel with loop regions. We show that PDPs are present in early divergent organisms from the green lineage and in all land plants. PAC domains are associated with other types of domains: Histidine-rich, extensin, Proline-rich, or yet uncharacterized. The earliest divergent organisms having PDPs are Bryophytes. Like the complexity of the cell walls, the number and complexity of PDPs steadily increase during the evolution of the green lineage. The association of PAC domains with other domains suggests a neo-functionalization and different types of interactions with cell wall polymers

Ethylene signaling modulates tomato pollen tube growth through modifications of cell wall remodeling and calcium gradient

“…A main feature regarding the cell wall‐related DEGs was that 17% and 28% of them encoded proteins possibly involved in pectin metabolism in NR versus WTB and in etr3‐ko versus WT, respectively (Figure 3; Table S4). These proteins belong to several families: PGs, of the glycosyl hydrolase family 28 (GH28), PMEs, of the carbohydrate esterase family 8 (CE8), pectate lyases (PLs) of the PL1 family, PME inhibitors (PMEIs), trichome birefringence‐like proteins (TBLs), and proline‐rich, Arabinogalactan, conserved cysteine (PAC) proteins (Hocq et al ., 2017; Nguyen‐Kim et al ., 2020; Stranne et al ., 2018). The number of DEGs encoding PGs and PMEs was higher in NR versus WTB than in etr3‐ko versus WT.…”

EAACIMolecular Allergology User's Guide 2.0

“…in approximately 10% of birch pollen‐sensitized subjects could occur 1218,1659,1660 . Moreover, these individuals are likely to have very high specific IgE levels to birch pollen 1213,1650,1651 . This type of soy allergy due to Bet v 1 cross‐reactions is considered the most prevalent soy allergy in northern and middle Europe, presumably also in North America (Canada, Northern states of the US), depending on the degree of birch pollen exposure.…”

“…1216,1658,1659 Moreover, these individuals are likely to have very high specific IgE levels to birch pollen. 1213,1650,1651 This type of soy allergy due to Bet v 1 cross-reactions is considered the most prevalent soy allergy in northern and middle Europe, presumably also in North America (Canada, Northern states of the US), depending on the degree of birch pollen exposure. Even in the Japanese adult population with a low prevalence of birch pollen allergy, this type of soy allergy has been observed and is associated with sensitization to Gly m 4 due to cross-reactivity to alder pollen sensitization.…”

Plant Cell Wall Proteins and Development

“…Eight experimental articles, nine up-to-date review articles, as well as a concept article, have been published. We wish to thank all the authors for their great contribution to this unique collection of articles as well as the International Journal of Molecular Science supporting team.The content of this Special Issue embraces several topics, all of them stressing the roles of cell wall proteins: cell wall proteomics studies on monocot species [7,12]; the role of cell wall proteins during plant development [13][14][15] or in response to environmental stresses [16][17][18][19]; overviews on several cell wall protein families either from green microalgae [20] or from plants, i.e., fasciclin arabinogalactan proteins (FLAs) [21,22], membrane-bound class III peroxidases (Class III Prxs) [23], pectin methylesterases inhibitors [24], DUF642 (Domain of Unknown Function 642) proteins [25], and Proline-rich, Arabinogalactan proteins, conserved Cysteines (PAC) domain-proteins [26]; and the role of fasciclin arabinogalactan proteins (FLAs) in Ca 2+ signaling during plant morphogenesis [27,28].For two decades, cell wall proteomics has become a powerful experimental approach and has revealed the diversity of the cell wall protein families. Arabidopsis thaliana has been the most studied plant species, and almost half of its expected cell wall proteome has been described so far (see WallProtDB, http://www.polebio.lrsv.ups-tlse.fr/WallProtDB/).…”

“…He et al [14] describe the evolution of FLAs which are possibly involved in signaling. Nguyen-Kim et al [26] explore the PAC domain-proteins family possibly forming non-covalent networks with polysaccharides and O-glycoproteins.…”