title: MIDGET connects COP1-dependent development with endoreduplication in Arabidopsis thaliana.
abstract: In Arabidopsis thaliana, loss of CONSTITUTIVE PHOTOMORPHOGENIC 1 (COP1) function leads to constitutive photomorphogenesis in the dark associated with inhibition of endoreduplication in the hypocotyl, and a post-germination growth arrest. MIDGET (MID), a component of the TOPOISOMERASE VI (TOPOVI) complex, is essential for endoreduplication and genome integrity in A. thaliana. Here we show that MID and COP1 interact in vitro and in vivo through the amino terminus of COP1. We further demonstrate that MID supports sub-nuclear accumulation of COP1. The MID protein is not degraded in a COP1-dependent fashion in darkness, and the phenotypes of single and double mutants prove that MID is not a target of COP1 but rather a necessary factor for proper COP1 activity with respect to both, control of COP1-dependent morphogenesis and regulation of endoreduplication. Our data provide evidence for a functional connection between COP1 and the TOPOVI in plants linking COP1-dependent development with the regulation of endoreduplication.
authors.affiliation: University of Cologne, Botanical Institute III, Zuelpicher Str. 47b, 50674, Koeln, Germany.
authors.forename: Andrea
authors.initials: A
authors.lastname: Schrader
authors.affiliation: University of Cologne, Botanical Institute III, Zuelpicher Str. 47b, 50674, Koeln, Germany.
authors.forename: Bastian
authors.initials: B
authors.lastname: Welter
authors.affiliation: University of Cologne, Botanical Institute III, Zuelpicher Str. 47b, 50674, Koeln, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Hulskamp
authors.affiliation: University of Cologne, Botanical Institute II, Zuelpicher Str. 47b, 50674, Koeln, Germany.
authors.forename: Ute
authors.initials: U
authors.lastname: Hoecker
authors.affiliation: University of Cologne, Botanical Institute III, Zuelpicher Str. 47b, 50674, Koeln, Germany.
authors.forename: Joachim F
authors.initials: JF
authors.lastname: Uhrig
mesh_terms: D000872:Anthocyanins / Q000378:metabolism; D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism / Q000648:ultrastructure; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D027101:DNA Topoisomerase IV / Q000235:genetics* / Q000378:metabolism; D003624:Darkness; D062951:Endoreduplication / Q000235:genetics*; D018506:Gene Expression Regulation, Plant; D018525:Germination; D018546:Hypocotyl / Q000235:genetics / Q000254:growth & development / Q000378:metabolism / Q000648:ultrastructure; D009097:Multienzyme Complexes; D009154:Mutation; D019697:Onions / Q000235:genetics / Q000378:metabolism; D010641:Phenotype; D018515:Plant Leaves / Q000235:genetics / Q000254:growth & development / Q000378:metabolism / Q000648:ultrastructure; D030821:Plants, Genetically Modified; D011003:Ploidies; D011993:Recombinant Fusion Proteins; D036226:Seedlings / Q000235:genetics / Q000254:growth & development / Q000378:metabolism / Q000648:ultrastructure; D014026:Nicotiana / Q000235:genetics / Q000378:metabolism; D020798:Two-Hybrid System Techniques; D044767:Ubiquitin-Protein Ligases / Q000235:genetics* / Q000378:metabolism
chemical_list: D000872:Anthocyanins; D029681:Arabidopsis Proteins; D009097:Multienzyme Complexes; D011993:Recombinant Fusion Proteins; C471983:AT2G32950 protein, Arabidopsis; D044767:Ubiquitin-Protein Ligases; D027101:DNA Topoisomerase IV