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Gewählte Doctoral Thesis:

Gernot Beihammer (2021): Identification of Lewis A containing glycoproteins in plants and elucidation of the structure of plant Glycosylphosphatidylinositol anchors.
Doctoral Thesis - Institut für Pflanzenbiotechnologie und Zellbiologie (IPBT), BOKU-Universität für Bodenkultur, pp 87. UB BOKU obvsg FullText

Data Source: ZID Abstracts
Terminal sugar residues on complex N-glycans affect the properties of the glycoproteins to which they are attached. In plants, the only known outer chain elongation of complex N-glycans are Lewis A structures. This glycan structure is conserved among plants, yet its abundance varies greatly between species and even tissues within the same organism. Lewis A bearing glycoproteins were isolated from Arabidopsis thaliana, Nicotiana benthamiana and Oryza sativa. As the majority of proteins identified in A. thaliana are involved in secondary cell wall biosynthesis, a potential phenotype of Lewis A deficient plants in terms of secondary cell wall composition was investigated. Plants lacking Lewis A glycans developed normally, however, and showed no alterations in cell wall constituents. Furthermore, a search of the 1001 genome database was conducted for natural accessions containing mutations in the genes encoding the glycosyltransferases required for Lewis A biosynthesis. Lewis A levels were investigated in selected accessions, but only one line was found to be devoid of Lewis A structures while most tested plants contained comparable amounts of Lewis A. Besides the role of Lewis A glycans, the structure of the glycan moiety of the plant Glycosylphosphatidylinositol (GPI) anchor was investigated. GPI anchored proteins are retained at the plasma membrane via their lipid moiety and play pivotal roles for plant fertility, stress response and signal transduction. Despite their significance, the structure of the GPI anchors has so far been shown for only one plant species, Pyrus communis. Here, the structure of the GPI glycan moiety was investigated in A. thaliana and N. benthamiana. GPI anchors in both plants were modified with a galactose β1,4-linked to the first mannose. The study presented here helps to close gaps in current knowledge of two important types of plant glycosylation, namely N-glycosylation and GPI anchors.

Betreuer: Strasser Richard
1. Berater: Altmann Friedrich

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