title: Uptake and effect of rare earth elements on gene expression in Methylosinus trichosporium OB3b.
abstract: It is well known that Methylosinus trichosporium OB3b has two forms of methane monooxygenase (MMO) responsible for the initial conversion of methane to methanol, a cytoplasmic (soluble) methane monooxygenase and a membrane-associated (particulate) methane monooxygenase, and that copper strongly regulates expression of these alternative forms of MMO. More recently, it has been discovered that M. trichosporium OB3b has multiple types of the methanol dehydrogenase (MeDH), i.e. the Mxa-type MeDH (Mxa-MeDH) and Xox-type MeDH (Xox-MeDH), and the expression of these two forms is regulated by the availability of the rare earth element (REE), cerium. Here, we extend these studies and show that lanthanum, praseodymium, neodymium and samarium also regulate expression of alternative forms of MeDH. The effect of these REEs on MeDH expression, however, was only observed in the absence of copper. Further, a mutant of M. trichosporium OB3b, where the Mxa-MeDH was knocked out, was able to grow in the presence of lanthanum, praseodymium and neodymium, but was not able to grow in the presence of samarium. Collectively, these data suggest that multiple levels of gene regulation by metals exist in M. trichosporium OB3b, but that copper overrides the effect of other metals by an as yet unknown mechanism.
authors.affiliation: Department of Civil and Environmental Engineering, University of Michigan, Ann Arbor, MI 48109-2125, USA.
authors.forename: Wenyu
authors.initials: W
authors.lastname: Gu
authors.affiliation: Department of Civil and Environmental Engineering, University of Michigan, Ann Arbor, MI 48109-2125, USA.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Farhan Ul Haque
authors.affiliation: Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA 50011, USA.
authors.forename: Alan A
authors.initials: AA
authors.lastname: DiSpirito
authors.affiliation: Department of Civil and Environmental Engineering, University of Michigan, Ann Arbor, MI 48109-2125, USA jsemrau@umich.edu.
authors.forename: Jeremy D
authors.initials: JD
authors.lastname: Semrau
mesh_terms: D000429:Alcohol Oxidoreductases / Q000235:genetics; D003300:Copper / Q000378:metabolism / Q000494:pharmacology; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects*; D007811:Lanthanum / Q000494:pharmacology; D008674:Metals, Rare Earth / Q000378:metabolism / Q000494:pharmacology*; D008697:Methane / Q000378:metabolism; D000432:Methanol / Q000378:metabolism; D020602:Methylosinus trichosporium / Q000187:drug effects* / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D009154:Mutation; D009354:Neodymium / Q000494:pharmacology; D010105:Oxygenases / Q000378:metabolism
chemical_list: D008674:Metals, Rare Earth; D009354:Neodymium; D007811:Lanthanum; D003300:Copper; D000429:Alcohol Oxidoreductases; C019641:alcohol dehydrogenase (acceptor); D010105:Oxygenases; C021555:methane monooxygenase; D008697:Methane; D000432:Methanol
keywords: copper; methane monooxygenase; methanol dehydrogenase; methanotrophy; rare earth elements