Transcriptional regulation of the respiratory genes in the cyanobacterium Synechocystis sp. PCC 6803 during the early response to glucose feeding.
The coordinated expression of the genes involved in respiration in the photosynthetic cyanobacterium Synechocystis sp. PCC 6803 during the early period of glucose (Glc) treatment is poorly understood. When photoautotrophically grown cells were supplemented with 10 mm Glc in the light or after a dark adaptation period of 14 h, significant increases in the respiratory activity, as determined by NAD(P)H turnover, respiratory O(2) uptake rate, and cytosolic alkalization, were observed. At the same time, the transcript levels of 18 genes coding for enzymes associated with respiration increased with differential induction kinetics; these genes were classified into three groups based on their half-rising times. Transcript levels of the four genes gpi, zwf, pdhB, and atpB started to increase along with a net increase in NAD(P)H, while the onset of net NAD(P)H consumption coincided with an increase in those of the genes tktA, ppc, pdhD, icd, ndhD2, ndbA, ctaD1, cydA, and atpE. In contrast, the expression of the atpI/G/D/A/C genes coding for ATP synthase subunits was the slowest among respiratory genes and their expression started to accumulate only after the establishment of cytosolic alkalization. These differential effects of Glc on the transcript levels of respiratory genes were not observed by inactivation of the genes encoding the Glc transporter or glucokinase. In addition, several Glc analogs could not mimic the effects of Glc. Our findings suggest that genes encoding some enzymes involved in central carbon metabolism and oxidative phosphorylation are coordinately regulated at the transcriptional level during the switch of nutritional mode.
Lee
Sanghyeob
S
Laboratory of Plant Genomics, Korea Research Institute of Bioscience and Biotechnology, Daejeon 305-806, Korea.
Ryu
Jee-Youn
JY
Kim
Soo Youn
SY
Jeon
Jae-Heung
JH
Song
Ji Young
JY
Cho
Hyung-Taeg
HT
Choi
Sang-Bong
SB
Choi
Doil
D
de Marsac
Nicole Tandeau
NT
Park
Youn-Il
YI
D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects*; D005947:Glucose / Q000378:metabolism / Q000494:pharmacology*; D040081:Protein Array Analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D046939:Synechocystis / Q000235:genetics* / Q000378:metabolism*; D014158:Transcription, Genetic / Q000187:drug effects*