title: Monitoring enzyme expression of a branched respiratory chain of corynebacterium glutamicum using an EGFP reporter gene.
abstract: To investigate the expressional control of branched respiratory chain complexes of the amino-acid producing bacterium Corynebacterium glutamicum according to growth conditions, the expression indexes of the ndh, sdh, qcrCAB, ctaCF, ctaD, ctaE, and cydAB genes were estimated under aerobic and microaerobic, and carbon-rich and -poor conditions. The promoter region of each target gene was cloned upstream of the EGFP gene on expression vector pVK6, and the nine reporter constructs were transformed into C. glutamicum ssp. lactofermentum. The cytochrome content of cellular membranes obtained from each growth phase closely corresponded to the expression indexes based on EGFP fluorescence and cell density, indicating that this rapid and convenient method is suitable for analyzing the expression levels of respiratory chain complexes. Using this method, we demonstrated that a reciprocal change in the expression levels of cytochrome bd-type and aa (3)-type oxidases occurs when C. glutamicum cells are held in stationary phase for extended periods.
authors.affiliation: Department of Bioscience and Bioinformatics, Kyushu Institute of Technology, 680-4 Kawazu, Iizuka, Fukuoka, 820-8502, Japan. tomo@bio.kyutech.ac.jp
authors.forename: Tomoichirou
authors.initials: T
authors.lastname: Kusumoto
authors.forename: Makoto
authors.initials: M
authors.lastname: Aoyagi
authors.forename: Hideo
authors.initials: H
authors.lastname: Iwai
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Kabashima
authors.forename: Junshi
authors.initials: J
authors.lastname: Sakamoto
mesh_terms: D001431:Bacteriological Techniques / Q000379:methods; D048230:Corynebacterium glutamicum / Q000201:enzymology* / Q000235:genetics; D004579:Electron Transport; D015964:Gene Expression Regulation, Bacterial; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins / Q000096:biosynthesis / Q000235:genetics*
chemical_list: C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins