title: Monitoring the enzyme expression in a respiratory chain of Corynebacterium glutamicum in a copper ion-supplemented culture medium.
abstract: Corynebacterium glutamicum has a branched respiratory chain: one of the branches is cytochrome bcc complex and cytochrome aa3-type cytochrome c oxidase, and the other is cytochrome bd-type menaquinol oxidase. The factors that influence the expression patterns of these respiratory enzymes remain unclear. To investigate the expressional control mechanism of the enzymes, we have previously constructed a promoter assay system utilizing enhanced green fluorescence protein. Here, we monitored respiratory enzymes' expression by using this system during growth in various culture media, with and without Cu(2+) ion supplementation. The promoter activities of cytochrome aa3 oxidase in the early stationary phase in the media supplemented with Cu(2+) ion at 40 or 400 μM were significantly increased 1.49-fold or 1.99-fold, respectively, as compared to the control. Moreover, the H(+)/O ratio, or the proton-pumping activity of the cells, increased about 1.6 times by the Cu(2+) supplementation. These facts indicate that copper ions can switch the branches.
authors.affiliation: a Department of Bioscience and Bioinformatics , Kyushu Institute of Technology , Fukuoka , Japan.
authors.forename: Tomoichirou
authors.initials: T
authors.lastname: Kusumoto
authors.forename: Makoto
authors.initials: M
authors.lastname: Aoyagi
authors.forename: Takahiko
authors.initials: T
authors.lastname: Sugiyama
authors.forename: Junshi
authors.initials: J
authors.lastname: Sakamoto
mesh_terms: D001692:Biological Transport / Q000187:drug effects; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D003300:Copper / Q000032:analysis / Q000494:pharmacology*; D048230:Corynebacterium glutamicum / Q000187:drug effects* / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D003470:Culture Media / Q000737:chemistry*; D004579:Electron Transport / Q000187:drug effects; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects*; D006418:Heme / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000235:genetics; D011522:Protons
chemical_list: D003470:Culture Media; D011522:Protons; D006418:Heme; D003300:Copper; D010100:Oxygen
keywords: Corynebacterium glutamicum; EGFP; copper ion; promoter activity; respiratory chain