Publications by authors named "B Mattei"
Article Synopsis
- In plants, cell wall fragments like oligogalacturonides (OGs) trigger immune responses by activating signal transduction pathways.
- Research on the protein DET3, a subunit of the vacuolar H-ATPase, revealed that its knockdown mutant (det3) showed reduced activation of defensive genes and other immune responses when exposed to OGs.
- The det3 mutant also demonstrated impaired endocytosis of OGs, linking DET3 to the internalization of these molecules, which is vital for maintaining a strong defense against pathogens like Botrytis cinerea.
Plasma membrane-associated Cation-binding Protein 1 (PCaP1) belongs to the plant-unique DREPP protein family with largely unknown biological functions but ascertained roles in plant development and calcium (Ca) signaling. PCaP1 is anchored to the plasma membrane via N-myristoylation and a polybasic cluster, and its N-terminal region can bind Ca/calmodulin (CaM). However, the molecular determinants of PCaP1-Ca-CaM interaction and the functional impact of myristoylation in the complex formation and Ca sensitivity of CaM remained to be elucidated.
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- Plants have developed resistance mechanisms to survive biotic stresses, with the Arabidopsis member BBE23 (renamed CELLOX2) being studied alongside the previously known CELLOX1.
- Both enzymes oxidize mixed-linked β-glucans that can activate plant immunity and help manage cell wall damage-associated molecular patterns.
- The two enzymes have different expression patterns, with CELLOX2 primarily expressed in the seed coat during early development, while knockout mutants display structural changes in the coat without significant alterations in monosaccharide composition.
Oligogalacturonide-oxidases (OGOXs) and cellodextrin-oxidase (CELLOX) are plant berberine bridge enzyme-like oligosaccharide-oxidases (OSOXs) that oxidize, respectively, oligogalacturonides (OGs) and cellodextrins (CDs), thereby inactivating their elicitor nature and concomitantly releasing HO. Little is known about the physiological role of OSOX activity. By using an ABTS-reduction assay, we identified a novel reaction mechanism through which the activity of OSOXs on cell wall oligosaccharides scavenged the radical cation ABTS with an efficiency dependent on the type and length of the oxidized oligosaccharide.
View Article and Find Full Text PDFBackground: 1,3-β-glucan is a polysaccharide widely distributed in the cell wall of several phylogenetically distant organisms, such as bacteria, fungi, plants and microalgae. The presence of highly active 1,3-β-glucanases in fungi evokes the biological question on how these organisms can efficiently metabolize exogenous sources of 1,3-β-glucan without incurring in autolysis.
Results: To elucidate the molecular mechanisms at the basis of 1,3-β-glucan metabolism in fungal saprotrophs, the putative exo-1,3-β-glucanase G9376 and a truncated form of the putative glucan endo-1,3-β-glucosidase (ΔG7048) from Penicillium sumatraense AQ67100 were heterologously expressed in Pichia pastoris and characterized both in terms of activity and structure.