Print Email Facebook Twitter Synthesis, processing and export of cytoplasmic endo-ß-1,4-xylanase from barley aleurone during germination Title Synthesis, processing and export of cytoplasmic endo-ß-1,4-xylanase from barley aleurone during germination Author Caspers, M.P.M. Lok, F. Sinjorgo, K.M.C. van Zeijl, M. Nielsen, K.A. Cameron-Mills, V. Centraal Instituut voor Voedingsonderzoek TNO Publication year 2001 Abstract We have identified the major endo-β-l,4-xylanase (XYN-1) in the aleurone of germinating barley grain, and show that it is expressed as a precursor of Mr 61 500 with both N- and C-terminal propeptides. XYN-1 is synthesized as an inactive enzyme in the cytoplasm, and only becomes active at a late stage of germination when the aleurone ceases to secrete hydrolases. A series of processing steps, mediated in part by aleurone cysteine endoproteases, yields a mature active enzyme of Mr 34 000. Processing and extracellular release of the mature enzyme coincide with the programmed cell death (PCD)-regulated disintegration of aleurone cells. We discuss the significance of delayed aleurone cell-wall degradation by endoxylanases in relation to the secretory capacity of the aleurone, and propose a novel role for aleurone PCD in facilitating the export of hydrolases. Chemicals/CAS: alpha-Amylase, EC 22.214.171.124; Cysteine Endopeptidases, EC 3.4.22.-; Endo-1,4-beta Xylanases, EC 126.96.36.199; Green Fluorescent Proteins, 147336-22-9; Hydrolases, EC 3.-; Indicators and Reagents; Luminescent Proteins; Plant Proteins; RNA Precursors; Starch, 9005-25-8; Xylosidases, EC 3.2.1.- Subject NutritionAmino Acid SequenceApoptosisBlotting, WesternCysteine EndopeptidasesCytoplasmEndo-1,4-beta XylanasesGene Expression Regulation, PlantGenes, PlantGerminationGreen Fluorescent ProteinsHordeumHydrolasesIndicators and ReagentsLuminescent ProteinsMicroscopy, ConfocalMolecular Sequence DataMolecular WeightPlant ProteinsProtoplastsRNA PrecursorsSeedsStarchXylosidasesHordeum vulgare subsp. vulgare To reference this document use: http://resolver.tudelft.nl/uuid:668caa99-e16c-4325-a518-c11105b1e9af DOI https://doi.org/10.1046/j.0960-7412.2001.01019.x TNO identifier 72511 ISSN 0960-7412 Source The Plant Journal, 26 (2), 191-204 Document type article Files To receive the publication files, please send an e-mail request to TNO Library.