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N -Glycosylation mediation of Plant Immunity in Arabidopsis Matt Borchardt and Jessica Allen. Max-Planck Society for the Advancement of Science. Originally created as the Kaiser Wilhelm Society in 1911, changed in 1948 Boasts 32 Nobel Prizes awarded to their scientists
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N-Glycosylation mediation of Plant Immunity in Arabidopsis Matt Borchardt and Jessica Allen
Max-Planck Society for the Advancement of Science • Originally created as the Kaiser Wilhelm Society in 1911, changed in 1948 • Boasts 32 Nobel Prizes awarded to their scientists • Top Non-University Institution in Science by Times Higher Education • Albert Einstein, Fritz Haber, and Peter Debye were named directors at some point in its history http://en.wikipedia.org/wiki/Max-Planck-Gesellschaft
Arabidopsis • Brassicaceae family • model organism • ABC Plant Model • First plant to have entire genome sequenced http://en.wikipedia.org/wiki/Arabidopsis
Signaling in Cells • Cells are constantly being introduced to various signals inside and outside of the cell • Signal receptors are signal-specific • Causes a cellular response
Example of Cell Signaling 219.221.200.61/ywwy/zbsw(E)/edetail6.htm
Cell Signaling and Plants • Cell signaling is important for Plant Immunity • Provides feedback systems to promote cellular defense • Growth inhibition • Production of Reactive Oxygen Species (ROS) • “oxidative burst” • Apoptosis
Plant Receptors • Pattern Recognition Receptors (PRRs) • membrane-bound protein of the innate immune system • recognize microbe-associated molecular patterns (MAMPs) on pathogens • Contain membrane-bound polysaccharides
Arabidopsis has approximately 56 known RLPs • EFR recognizes and responds to elf18 • FLS2 recognizes and responds to flg22 • MAMPs are recognized by N-glycans on PRRs
N-Glycans • Attach to asparagine residues of plasma membrane • Initial contact between plant cells and pathogens
N-glycosylation • Occurs in eukaryotes during/after translation • Linking of 14-sugar precursor to the asparagine in the polypeptide chain 12-52.Molecular Biology of the Cell, 4th Edition
Oligosaccharyltransferase Complex • Transfers the 14-sugar oligosaccharide from dolichol to the protein • The central step in N-linked glycosylation • Located in the ER • Post-translational modification http://www.ier.tokushima-u.ac.jp/bunshi-seiri/physiol/images/PfSTT3.jpg
Altered/Prevention of N-Glycosylation • Creates unfolding of proteins • Only correctly folded proteins are exported from the ER • Causes a reduction in receptor accumulation • Causes lack of receptor-signal induced pathways • Leads to decreased immune response
In this study • Mutated genes produce plants with modifications in the N-glycosylation steps • stt3a • Genes present in ER which encode for oligosaccharyltransferase complex
Tunicamycin • Antibiotic • Blocks glycoprotein synthesis in first step of glycosylation • Causes arrest of cell cycle in G1 • Produced by bacterium Streptomyces http://fermentek.co.il/tunicamycin.htm
MAMP MAMP Bacteria Bacteria PRR-EFR PRR-FLS2 Plasma Membrane Seedling Growth ROS Endoplasmic Reticulum Golgi Apparatus