title: Differential Top10 promoter regulation by six tetracycline analogues in plant cells.
abstract: The effects of five tetracycline analogues, anhydrotetracycline, doxycycline, minocycline, oxytetracycline, and tetracycline, on Top10 promoter activity in NT1 tobacco tissue culture cells have been analysed. The concentration that repressed Top10 promoter activity, the level of transgene repression and the kinetics of transgene de-repression were determined for each analogue, and could not be predicted from in vitro binding affinity to the tetracycline repressor or from comparison with animal cells. Doxycycline had the most potent effect on the Top10 promoter and completely inhibited transgene expression at 4 nmol l(-1). Tetracycline was the most versatile of the analogues tested; tetracycline inhibited the Top10 promoter at 10 nmol l(-1) and was easily washed out to restore Top10-driven expression in 12-24 h. A study was also made of the suitability for plant research of a novel tetracycline analogue, GR33076X. In animal cells, GR33076X de-repressed Top10 promoter activity in the presence of inhibitory concentrations of anhydrotetracycline. In NT1, it is shown that GR 33076X can antagonize repression of the Top10 promoter in the presence of tetracycline, but not of anhydrotetracycline or of doxycycline. Different tetracycline analogues can therefore be used to regulate the Top10 promoter in plant cells and this property may be exploited in planning an optimum course of transgene regulation.
authors.affiliation: Department of Plant Sciences, University of Cambridge, Downing Site, Cambridge CB2 3EA, UK. john.love@plantsci.cam.ac.uk
authors.forename: John
authors.initials: J
authors.lastname: Love
authors.forename: George C
authors.initials: GC
authors.lastname: Allen
authors.forename: Christiane
authors.initials: C
authors.lastname: Gatz
authors.forename: William F
authors.initials: WF
authors.lastname: Thompson
mesh_terms: D016960:Agrobacterium tumefaciens / Q000235:genetics; D002460:Cell Line; D004318:Doxycycline / Q000494:pharmacology; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D005966:Glucuronidase / Q000235:genetics / Q000378:metabolism; D008911:Minocycline / Q000494:pharmacology; D010118:Oxytetracycline / Q000494:pharmacology; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic / Q000235:genetics*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012097:Repressor Proteins / Q000235:genetics; D013754:Tetracyclines / Q000737:chemistry / Q000494:pharmacology*; D014026:Nicotiana / Q000166:cytology / Q000187:drug effects* / Q000235:genetics; D014162:Transfection
chemical_list: C101163:GR 33076X; D011993:Recombinant Fusion Proteins; D012097:Repressor Proteins; D013754:Tetracyclines; C016229:4-epianhydrotetracycline; D005966:Glucuronidase; D008911:Minocycline; D004318:Doxycycline; D010118:Oxytetracycline
keywords: NASA Discipline Plant Biology; Non-NASA Center