This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Olmedo-Verd, E.
Right arrow Articles by Muro-Pastor, A. M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Olmedo-Verd, E.
Right arrow Articles by Muro-Pastor, A. M.

 Previous Article  |  Next Article 

Journal of Bacteriology, March 2005, p. 1985-1991, Vol. 187, No. 6
0021-9193/05/$08.00+0     doi:10.1128/JB.187.6.1985-1991.2005
Copyright © 2005, American Society for Microbiology. All Rights Reserved.

HetR-Dependent and -Independent Expression of Heterocyst-Related Genes in an Anabaena Strain Overproducing the NtcA Transcription Factor

Elvira Olmedo-Verd, Enrique Flores, Antonia Herrero, and Alicia M. Muro-Pastor*

Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas-Universidad de Sevilla, Seville, Spain

Received 7 October 2004/ Accepted 13 December 2004

Heterocyst development in the cyanobacterium Anabaena sp. strain PCC 7120 depends on both the global nitrogen control transcription factor NtcA and the cell differentiation regulatory protein HetR, with expression of ntcA and hetR being dependent on each other. In this study we constructed strains that constitutively express the ntcA gene leading to high levels of NtcA protein irrespective of the nitrogen source, and we analyzed the effects of such NtcA levels on heterocyst differentiation. In the NtcA-overproducing strain, heterocyst differentiation, induction of NtcA-dependent heterocyst development genes or operons such as devBCA or the cox2 operon, and NtcA-dependent excision of the 11-kb nifD-intervening element only took place under nitrogen deficiency. Although functional heterocysts were produced in response to nitrogen step-down, the NtcA overproducing strain could not grow diazotrophically. Overexpression of ntcA in a hetR background promoted expression of devBCA in response to ammonium withdrawal and excision of the 11-kb element even in the presence of combined nitrogen. Our results show that some NtcA-dependent heterocyst-related genes can be expressed independently of HetR.

* Corresponding author. Mailing address: Instituto de Bioquímica Vegetal y Fotosíntesis, Centro de Investigaciones Científicas Isla de la Cartuja, Avda. Américo Vespucio 49, E-41092 Seville, Spain. Phone: 34-95-448-9523. Fax: 34-95-446-0065. E-mail: alicia{at}ibvf.csic.es.

Journal of Bacteriology, March 2005, p. 1985-1991, Vol. 187, No. 6
0021-9193/05/$08.00+0     doi:10.1128/JB.187.6.1985-1991.2005
Copyright © 2005, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:

  • Olmedo-Verd, E., Valladares, A., Flores, E., Herrero, A., Muro-Pastor, A. M. (2008). Role of Two NtcA-Binding Sites in the Complex ntcA Gene Promoter of the Heterocyst-Forming Cyanobacterium Anabaena sp. Strain PCC 7120. J. Bacteriol. 190: 7584-7590 [Abstract] [Full Text]  
  • Valladares, A., Flores, E., Herrero, A. (2008). Transcription Activation by NtcA and 2-Oxoglutarate of Three Genes Involved in Heterocyst Differentiation in the Cyanobacterium Anabaena sp. Strain PCC 7120. J. Bacteriol. 190: 6126-6133 [Abstract] [Full Text]  
  • Moslavac, S., Nicolaisen, K., Mirus, O., Al Dehni, F., Pernil, R., Flores, E., Maldener, I., Schleiff, E. (2007). A TolC-Like Protein Is Required for Heterocyst Development in Anabaena sp. Strain PCC 7120. J. Bacteriol. 189: 7887-7895 [Abstract] [Full Text]  
  • Shi, L., Li, J.-H., Cheng, Y., Wang, L., Chen, W.-L., Zhang, C.-C. (2007). Two Genes Encoding Protein Kinases of the HstK Family Are Involved in Synthesis of the Minor Heterocyst-Specific Glycolipid in the Cyanobacterium Anabaena sp. Strain PCC 7120. J. Bacteriol. 189: 5075-5081 [Abstract] [Full Text]  
  • Laurent, S., Chen, H., Bedu, S., Ziarelli, F., Peng, L., Zhang, C.-C. (2005). From the Cover: Nonmetabolizable analogue of 2-oxoglutarate elicits heterocyst differentiation under repressive conditions in Anabaena sp. PCC 7120. Proc. Natl. Acad. Sci. USA 102: 9907-9912 [Abstract] [Full Text]  


Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»