title: Interaction of the tobacco lectin with histone proteins.
abstract: The tobacco (Nicotiana tabacum) agglutinin or Nictaba is a member of a novel class of plant lectins residing in the nucleus and the cytoplasm of tobacco cells. Since tobacco lectin expression is only observed after the plant has been subjected to stress situations such as jasmonate treatment or insect attack, Nictaba is believed to act as a signaling protein involved in the stress physiology of the plant. In this paper, a nuclear proteomics approach was followed to identify the binding partners for Nictaba in the nucleus and the cytoplasm of tobacco cv Xanthi cells. Using lectin affinity chromatography and pull-down assays, it was shown that Nictaba interacts primarily with histone proteins. Binding of Nictaba with histone H2B was confirmed in vitro using affinity chromatography of purified calf thymus histone proteins on a Nictaba column. Elution of Nictaba-interacting histone proteins was achieved with 1 m N-acetylglucosamine (GlcNAc). Moreover, mass spectrometry analyses indicated that the Nictaba-interacting histone proteins are modified by O-GlcNAc. Since the lectin-histone interaction was shown to be carbohydrate dependent, it is proposed that Nictaba might fulfill a signaling role in response to stress by interacting with O-GlcNAcylated proteins in the plant cell nucleus.
authors.affiliation: Laboratory of Biochemistry and Glycobiology, Department of Molecular Biotechnology, Faculty of Bioscience Engineering, Ghent University, B-9000 Ghent, Belgium.
authors.forename: Dieter
authors.initials: D
authors.lastname: Schouppe
authors.forename: Bart
authors.initials: B
authors.lastname: Ghesquière
authors.forename: Gerben
authors.initials: G
authors.lastname: Menschaert
authors.forename: Winnok H
authors.initials: WH
authors.lastname: De Vos
authors.forename: Stéphane
authors.initials: S
authors.lastname: Bourque
authors.forename: Geert
authors.initials: G
authors.lastname: Trooskens
authors.forename: Paul
authors.initials: P
authors.lastname: Proost
authors.forename: Kris
authors.initials: K
authors.lastname: Gevaert
authors.forename: Els J M
authors.initials: EJ
authors.lastname: Van Damme
mesh_terms: D000117:Acetylglucosamine / Q000378:metabolism; D000818:Animals; D000906:Antibodies / Q000378:metabolism; D002417:Cattle; D002457:Cell Extracts; D002458:Cell Fractionation; D002467:Cell Nucleus / Q000378:metabolism; D002478:Cells, Cultured; D002846:Chromatography, Affinity; D004721:Endoplasmic Reticulum / Q000378:metabolism; D006031:Glycosylation; D006657:Histones / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D013058:Mass Spectrometry; D037121:Plant Lectins / Q000378:metabolism*; D011485:Protein Binding; D011523:Protoplasts / Q000378:metabolism; D013379:Substrate Specificity; D014026:Nicotiana / Q000166:cytology / Q000378:metabolism*; D014909:Wheat Germ Agglutinins / Q000378:metabolism
chemical_list: D000906:Antibodies; D002457:Cell Extracts; D006657:Histones; D037121:Plant Lectins; D014909:Wheat Germ Agglutinins; D000117:Acetylglucosamine