Characterization of citrate utilization in Corynebacterium glutamicum by transcriptome and proteome analysis.
Corynebacterium glutamicum grows aerobically on a variety of carbohydrates and organic acids as single or combined sources of carbon and energy. To characterize the citrate utilization in C. glutamicum on a genomewide scale, a comparative analysis was carried out by combining transcriptome and proteome analysis. In cells grown on citrate, transcriptome analysis revealed highest expression changes for two different citrate-uptake systems encoded by citM and tctCBA, whereas genes encoding uptake systems for the glucose- (ptsG), sucrose- (ptsS) and fructose- (ptsF) specific PTS components and permeases for gluconate (gntP) and glutamate (gluC) displayed decreased mRNA levels in citrate-grown cells. This pattern was also observed when cells grown in Luria-Bertani (LB) medium plus citrate were compared with cells grown in LB medium, indicating some kind of catabolite repression. Genes encoding enzymes of the tricarboxylic acid cycle (aconitase, succinyl-CoA synthetase, succinate dehydrogenase and fumarase), malic enzyme, PEP carboxykinase, gluconeogenic glyceraldehyde-3-phosphate dehydrogenase and ATP synthase displayed increased expression in cells grown on citrate. Accordingly, proteome analysis revealed elevated protein levels of these enzymes and showed a good correlation with the mRNA levels. In conclusion, this study revealed the citrate stimulon in C. glutamicum and the regulated central metabolic genes when grown on citrate.
Polen
Tino
T
Institute of Biotechnology, Research Centre Jülich, Jülich, Germany. t.polen@fz-juelich.de
Schluesener
Daniela
D
Poetsch
Ansgar
A
Bott
Michael
M
Wendisch
Volker F
VF
D001426:Bacterial Proteins / Q000032:analysis* / Q000235:genetics*; D019343:Citric Acid / Q000378:metabolism*; D048230:Corynebacterium glutamicum / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D053858:Metabolic Networks and Pathways / Q000235:genetics; D020411:Oligonucleotide Array Sequence Analysis; D020543:Proteome / Q000032:analysis*; D012333:RNA, Messenger / Q000032:analysis*
D001426:Bacterial Proteins; D020543:Proteome; D012333:RNA, Messenger; D019343:Citric Acid