New papers from the Schwab, Braun and Ott labs.
Breeding of hypoallergenic strawberry fruit.
Katrin Franz, Bernadette Eberlein, Stephanie Hücherig, Kathrin Edelmann, Fatma Besbes, Johannes Ring, Ulf Darsow, Wilfried Schwab (2013).
Allergy to food is a hypersensitivity disorder of the immune system to normally harmless food ingredients. A promising solution for allergenic patients is the development of hypoallergenic food. OBJECTIVE: Selection and breeding of low-allergenic variety is the conventional strategy to produce hypoallergenic food. The strawberry fruit proteins Fra a 1.01E, Fra a 1.02 and Fra a 1.03 are homologous of the major birch pollen allergen Bet v1 but their individual allergenic potentials are unknown. METHOD: We produced the recombinant Fra a allergens and evaluated their cross allergenic potential in birch pollen allergic patients by a basophil activation test. Anti-Fra a 1.02 antibodies were also used to screen for allergen deficient strawberry lines. RESULTS: Although Fra a 1.01E, Fra a 1.02 and Fra a 1.03 have sequence similarities of 70, 71 and 74% with Bet v 1 Fra a 1.02 showed the highest allergenic potential. The data support the role of Fra a 1.02 as the major allergen for individuals affected by a strawberry allergy. The screening of strawberry varieties detected genotypes with significantly reduced levels of the allergen. CONCLUSION: Genotypes with reduced Fra a 1.02 proteins might serve as starting material for the breeding of hypoallergenic strawberry varieties.
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Plasma Membranes Are Subcompartmentalized into a Plethora of Coexisting and Diverse Microdomains in Arabidopsis and Nicotiana benthamiana.
Iris K. Jarsch, Sebastian S.A. Konrad, Thomas F. Stratil, Susan L. Urbanus, Witold Szymanski, Pascal Braun, Karl-Heinz Braun and Thomas Ott (2014)
Eukaryotic plasma membranes are highly compartmentalized structures. So far, only a few individual proteins that function in a wide range of cellular processes have been shown to segregate into microdomains. However, the biological roles of most microdomain-associated proteins are unknown. Here, we investigated the heterogeneity of distinct microdomains and the complexity of their coexistence. This diversity was determined in living cells of intact multicellular tissues using 20 different marker proteins from Arabidopsis thaliana, mostly belonging to the Remorin protein family. These proteins associate with microdomains at the cytosolic leaflet of the plasma membrane. We characterized these membrane domains and determined their lateral dynamics by extensive quantitative image analysis. Systematic colocalization experiments with an extended subset of marker proteins tested in 45 different combinations revealed the coexistence of highly distinct membrane domains on individual cell surfaces. These data provide valuable tools to study the lateral segregation of membrane proteins and their biological functions in living plant cells. They also demonstrate that widely used biochemical approaches such as detergent-resistant membranes cannot resolve this biological complexity of membrane compartmentalization in vivo.
