Requirement of the regulatory protein NtcA for the expression of nitrogen assimilation and heterocyst development genes in the cyanobacterium Anabaena sp. PCC7120

  title={Requirement of the regulatory protein NtcA for the expression of nitrogen assimilation and heterocyst development genes in the cyanobacterium Anabaena sp. PCC7120},
  author={José E. Frías and Enrique Flores and Antonia Herrero},
  journal={Molecular Microbiology},
The cyanobacterial ntcA gene encodes a DNA‐binding protein that belongs to the Crp family of bacterial transcriptional regulators. In this work, we describe the isolation of an ntcA insertional mutant of the dinitrogen‐fixing, heterocyst‐forming cyanobacterium Anabaena sp. PCC 7120. The Anabaena ntcA mutant was able to use ammonium as a source of nitrogen for growth, but was unable to assimilate atmospheric nitrogen (dinitrogen) or nitrate. Nitrogenase and enzymes of the nitrate reduction… 

Open Reading Frame all0601 from Anabaena sp. Strain PCC 7120 Represents a Novel Gene, cnaT, Required for Expression of the Nitrate Assimilation nir Operon

An insertional mutant of cnaT was generated and found to be unable to assimilate nitrate, although it could use ammonium or dinitrogen as a source of nitrogen for growth, and the previously described regulatory elements, NtcA and NtcB, is discussed.

Activation of the Anabaena nir operon promoter requires both NtcA (CAP family) and NtcB (LysR family) transcription factors

Results showed that NtcB, a LysR‐ family protein, is required in addition to NtcA, a CAP‐family protein, for the expression of genes encoding proteins specifically involved in nitrate assimilation in Anabaena sp.

Nitrate assimilation gene cluster from the heterocyst-forming cyanobacterium Anabaena sp. strain PCC 7120

A region of the genome of the filamentous, nitrogen-fixing, heterocyst-forming cyanobacterium Anabaena sp. strain PCC 7120 that contains a cluster of genes involved in nitrate assimilation has been

Role of NtcA, a cyanobacterial global nitrogen regulator, in the regulation of sucrose metabolism gene expression in Anabaena sp. PCC 7120

It is concluded that sucrose metabolism is coordinated at the transcriptional level with nitrogen metabolism, suggesting a global metabolism regulating role for NtcA.

Regulation of ntcA Expression and Nitrite Uptake in the Marine Synechococcus sp. Strain WH 7803

Nitrite and nitrate act as specific inducers for the synthesis of proteins required for nitrite uptake in cyanobacteria cloned and sequenced, suggesting that ntcA expression is not sufficient for uptake capacity to develop.

The Global Nitrogen Regulator NtcA Regulates Transcription of the Signal Transducer PII (GlnB) and Influences Its Phosphorylation Level in Response to Nitrogen and Carbon Supplies in the Cyanobacterium Synechococcus sp. Strain PCC 7942

A good correlation between the amounts of the two transcript species and the PII protein was observed, as revealed by immunodetection with specific antibodies, and the phosphorylation level of PII in the wild type is inversely correlated with nitrogen availability and directly correlated with higher CO2 concentration.

Transcription of glutamine synthetase genes (glnA and glnN) from the cyanobacterium Synechocystis sp. strain PCC 6803 is differently regulated in response to nitrogen availability

It is shown that expression of both the glnA and glnN genes is subjected to transcriptional regulation in response to changes in nitrogen availability, and that an additional modification of NtcA or an additional factor is required for the regulation of glnnN gene expression.

NrrA, a nitrogen‐responsive response regulator facilitates heterocyst development in the cyanobacterium Anabaena sp. strain PCC 7120

It is concluded that the nrrA gene, which encodes a response regulator of the OmpR family with a DNA‐binding domain, facilitates heterocyst development.

Posttranscriptional Regulation of Glutamine Synthetase in the Filamentous Cyanobacterium Anabaena sp. PCC 7120: Differential Expression between Vegetative Cells and Heterocysts

In vitro studies demonstrate that Anabaena GS is not inactivated by Synechocystis IFs (IF7 and IF17), indicating the specificity of the system and differential expression of the IF system between heterocysts and vegetative cells of AnabaENA.

The NtcA-Dependent P1 Promoter Is Utilized for glnA Expression in N2-Fixing Heterocysts of Anabaena sp. Strain PCC 7120

The NtcA-binding site in the P1 promoter and binding of NTCA to this site appear to be key factors in determining glnA gene expression in vegetative cells and heterocysts.



NtcA, a global nitrogen regulator from the cyanobacterium Synechococcus that belongs to the Crp family of bacterial regulators

The gene ntcA is proposed to encode a transcriptional activator of genes subject to nitrogen control in Synechococcus, and of special biological significance, is the presence of a conserved helix‐turn‐helix motif in the sequence close to the C‐terminal end of all the proteins in the family.

Molecular mechanism for the operation of nitrogen control in cyanobacteria.

In cyanobacteria, ammonium exerts a negative regulation of the expression of proteins involved in the assimilation of nitrogen sources alternative to ammonium. In Synechococcus, mRNA levels of genes

Regulation of nitrate reductase levels in the cyanobacteria Anacystis nidulans, Anabaena sp. strain 7119, and Nostoc sp. strain 6719

In the unicellular species Anacystis nidulans, nitrate reductase was repressed in the presence of ammonium but de novo enzyme synthesis took place in media containing either nitrate or not nitrogen source, indicating that nitrate was not required as an obligate inducer.

Synthesis of nitrogenase in mutants of the cyanobacterium Anabaena sp. strain PCC 7120 affected in heterocyst development or metabolism

It is concluded that internal partial oxygen pressure sufficient to inactivate nitrogenase is insufficient to repress synthesis of the enzyme completely; among mutants with an apparently intact heterocyst envelope and normal respiration, three had virtually undetectable levels of dinitrogenase reductase under all conditions employed.

General distribution of the nitrogen control gene ntcA in cyanobacteria

Sequence analysis has shown that these ntcA genes would encode polypeptides strongly similar (77 to 79% identity) to the Synechococcus NtcA protein.

Isolation and characterization of the gene encoding the principal sigma factor of the vegetative cell RNA polymerase from the cyanobacterium Anabaena sp. strain PCC 7120

The filamentous cyanobacterium Anabaena sp. strain PCC 7120 responds to combined nitrogen deprivation by forming specialized nitrogen-fixing cells at regular intervals along the filament. Genetic and

Developmental regulation and spatial pattern of expression of the structural genes for nitrogenase in the cyanobacterium Anabaena.

Results provide evidence for a causal relationship between development and transcriptional events in Anabaena and three lines of evidence indicate that the mutant has retained the ability to develop a pattern despite its inability to make heterocysts.

Identification and cloning of a regulatory gene for nitrogen assimilation in the cyanobacterium Synechococcus sp. strain PCC 7942

Twenty-seven mutants that were unable to assimilate nitrate were isolated from Synechococcus sp. strain PCC 7942. In addition to mutants that lacked nitrate reductase or nitrite reductase, seven

Anabaena sp. strain PCC 7120 bifA gene encoding a sequence-specific DNA-binding protein cloned by in vivo transcriptional interference selection

The bifA gene is cloned by using a genetic selection strategy to identify a 672-bp open reading frame that encoded VF1-like binding activity and shows 77% identity to NtcA, which is a global regulator involved in nitrogen control in Synechococcus sp.