Gene expression of Corynebacterium glutamicum in response to the conditions inducing glutamate overproduction.
OBJECTIVE
The ultimate aim is to elucidate the molecular mechanisms for glutamate overproduction by Corynebacterium glutamicum.


RESULTS
Gene expression in response to the conditions inducing glutamate overproduction was investigated by using a DNA microarray technique. Most genes involved in the EMP pathway, the PPP, and the TCA cycle were downregulated, while five genes that were highly upregulated (NCgl0917, NCgl2944, NCgl2945, NCgl2946, and NCgl2975) were identified under all the three conditions for overproduction that are studied here. Gene products of NCgl2944, NCgl2945, and NCgl2946 were highly homologous to each other, did not resemble any other protein, and have remained uncharacterized thus far. The product of NCgl0917 showed a similarity to a few hypothetical and uncharacterized proteins. NCgl2975 was homologous to metal-binding proteins.


CONCLUSIONS
The decrease in the activity of 2-oxoglutarate dehydrogenase complex, a key enzyme that is downregulated during glutamate overproduction, can be mainly attributed to the downregulation of odhA and sucB. Five highly upregulated genes were also identified.


CONCLUSIONS
Although fermentative production of glutamate has been carried out for more than 45 years, information on the molecular mechanisms of glutamate overproduction is still limited. This study further elucidates these mechanisms.
Kataoka
M
M
Department of Biotechnology, Graduate School of Agriculture and Life Sciences, The University of Tokyo, Tokyo, Japan.
Hashimoto
K-I
KI
Yoshida
M
M
Nakamatsu
T
T
Horinouchi
S
S
Kawasaki
H
H
D002952:Citric Acid Cycle / Q000235:genetics; D048230:Corynebacterium glutamicum / Q000235:genetics* / Q000378:metabolism; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D018698:Glutamic Acid / Q000096:biosynthesis*; D006019:Glycolysis / Q000235:genetics; D020411:Oligonucleotide Array Sequence Analysis; D010427:Pentose Phosphate Pathway / Q000235:genetics; D017385:Sequence Homology
D018698:Glutamic Acid