Journalartikel

Jahr der Veröffentlichung: 2003

Seiten: 2582-2591

Zeitschrift: Journal of Bacteriology

Bandnummer: 185

Heftnummer: 8

ISSN: 0021-9193

eISSN: 1098-5530

Open Access Status: Green

DOI Link: https://doi.org/10.1128/JB.185.8.2582-2591.2003

Verlag: American Society for Microbiology

Abstract: 
The transcription factor of the cyclic AMP receptor protein/FNR family, NtcA, and the P-II signaling protein play central roles in global nitrogen control in cyanobacteria. A dependence on P-II for NtcA-regulated transcription, however, has not been observed. In the present investigation, we examined alterations in gene expression following nitrogen deprivation in Synechococcus elongatus strain PCC 7942 and specifically the roles of NtcA and P-II. Global changes in de novo protein synthesis following combined-nitrogen deprivation were visualized by in vivo [S-35] methionine labeling and two-dimensional polyacrylamide gel electrophoresis analysis. Nearly all proteins whose synthesis responded specifically to combined-nitrogen deprivation in wild-type cells of S. elongatus failed to respond in P-II- and NtcA-deficient mutants. One of the proteins whose synthesis was down-regulated in a P-II- and NtcA-dependent manner was RbcS, the small subunit of RubisCO. Quantification of its mRNA revealed that the abundance of the rbcLS transcript following combined-nitrogen deprivation rapidly declined in wild-type cells but not in P-II and NtcA mutant cells. To investigate further the relationship between P-II and NtcA, fusions of the promotorless luxAB reporter genes to the NtcA-regulated gInB gene were constructed and these constructs were used to transform wild-type cells and P-II(-) and NtcA(-)mutants. Determination of bioluminescence under different growth conditions showed that NtcA represses gene expression in the presence of ammonium in a P-II-independent manner. By contrast, NtcA-dependent activation of gInB expression following combined-nitrogen deprivation was impaired in the absence of P-II. Together, these results suggest that under conditions of combined-nitrogen deprivation, the regulation of NtcA-dependent gene expression requires the P-II signal transduction protein.

Harvard-Zitierstil: Aldehni, M., Sauer, J., Spielhaupter, C., Schmid, R. and Forchhammer, K. (2003) Signal transduction protein P_II is required for NtcA-regulated gene expression during nitrogen deprivation in the cyanobacterium Synechococcus elongatus strain PCC 7942, Journal of Bacteriology, 185(8), pp. 2582-2591. https://doi.org/10.1128/JB.185.8.2582-2591.2003

APA-Zitierstil: Aldehni, M., Sauer, J., Spielhaupter, C., Schmid, R., & Forchhammer, K. (2003). Signal transduction protein P_II is required for NtcA-regulated gene expression during nitrogen deprivation in the cyanobacterium Synechococcus elongatus strain PCC 7942. Journal of Bacteriology. 185(8), 2582-2591. https://doi.org/10.1128/JB.185.8.2582-2591.2003