title: Marker gene tethering by nucleoporins affects gene expression in plants.
abstract: In non-plant systems, chromatin association with the nuclear periphery affects gene expression, where interactions with nuclear envelope proteins can repress and interactions with nucleoporins can enhance transcription. In plants, both hetero- and euchromatin can localize at the nuclear periphery, but the effect of proximity to the nuclear periphery on gene expression remains largely unknown. This study explores the putative function of Seh1 and Nup50a nucleoporins on gene expression by using the Lac Operator / Lac Repressor (LacI-LacO) system adapted to Arabidopsis thaliana. We used LacO fused to the luciferase reporter gene (LacO:Luc) to investigate whether binding of the LacO:Luc transgene to nucleoporin:LacI protein fusions alters luciferase expression. Two separate nucleoporin-LacI-YFP fusions were introduced into single insert, homozygous LacO:Luc Arabidopsis plants. Homozygous plants carrying LacO:Luc and a single insert of either Seh1-LacI-YFP or Nup50a-LacI-YFP were tested for luciferase activity and compared to plants containing LacO:Luc only. Seh1-LacI-YFP increased, while Nup50a-LacI-YFP decreased luciferase activity. Seh1-LacI-YFP accumulated at the nuclear periphery as expected, while Nup50a-LacI-YFP was nucleoplasmic and was not selected for further study. Protein and RNA levels of luciferase were quantified by western blotting and RT-qPCR, respectively. Increased luciferase activity in LacO:Luc+Seh1-LacI-YFP plants was correlated with increased luciferase protein and RNA levels. This change of luciferase expression was abolished by disruption of LacI-LacO binding by treating with IPTG in young seedlings, rosette leaves and inflorescences. This study suggests that association with the nuclear periphery is involved in the regulation of gene expression in plants.
authors.affiliation: a Department of Biological and Medical Sciences ; Faculty of Health and Life Sciences; Oxford Brookes University ; Headington , Oxford , UK.
authors.forename: Sarah
authors.initials: S
authors.lastname: Smith
authors.affiliation: a Department of Biological and Medical Sciences ; Faculty of Health and Life Sciences; Oxford Brookes University ; Headington , Oxford , UK.
authors.forename: Carla
authors.initials: C
authors.lastname: Galinha
authors.affiliation: b UMR CNRS 6247; INSERM U931 GReD Clermont Universités 24 ; Aubiere , France.
authors.forename: Sophie
authors.initials: S
authors.lastname: Desset
authors.affiliation: a Department of Biological and Medical Sciences ; Faculty of Health and Life Sciences; Oxford Brookes University ; Headington , Oxford , UK.
authors.forename: Frances
authors.initials: F
authors.lastname: Tolmie
authors.affiliation: a Department of Biological and Medical Sciences ; Faculty of Health and Life Sciences; Oxford Brookes University ; Headington , Oxford , UK.
authors.forename: David
authors.initials: D
authors.lastname: Evans
authors.affiliation: b UMR CNRS 6247; INSERM U931 GReD Clermont Universités 24 ; Aubiere , France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Tatout
authors.affiliation: a Department of Biological and Medical Sciences ; Faculty of Health and Life Sciences; Oxford Brookes University ; Headington , Oxford , UK.
authors.forename: Katja
authors.initials: K
authors.lastname: Graumann
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation; D017930:Genes, Reporter; D056968:Lac Repressors / Q000235:genetics; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D008856:Microscopy, Fluorescence; D028861:Nuclear Pore Complex Proteins / Q000235:genetics* / Q000378:metabolism; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D029681:Arabidopsis Proteins; D001426:Bacterial Proteins; D056968:Lac Repressors; D008164:Luminescent Proteins; D028861:Nuclear Pore Complex Proteins; D012333:RNA, Messenger; C515667:Sec13 homolog 1, Arabidopsis; C054562:yellow fluorescent protein, Bacteria
keywords: Arabidopsis thaliana; LacO:LacI; Nuclear pore complex; Seh1; chromatin organization; gene expression; higher plant