Project description:NtcA regulates primary in a unicelluar cyanobacterium Synechocystis sp. PCC6803. We constructed an ntcA-overexpressing strain, named NOX10, by introducing the ntcA genes fusing psbAII promoter by homologous recombination. The transcript profiles of parental wild-type strain GT and NOX10 were compared by microarray CyanoChip (Takrara bio.). Experiments were performed two times with biologically independent RNA. Total RNAs from two independent wild-type (GT) and two independent ntcA-overexpressing strains were differently labeled by Cy3 or Cy5, followed by hybridization on CyanoChip.
Project description:NtcA regulates primary in a unicelluar cyanobacterium Synechocystis sp. PCC6803. We constructed an ntcA-overexpressing strain, named NOX10, by introducing the ntcA genes fusing psbAII promoter by homologous recombination. The transcript profiles of parental wild-type strain GT and NOX10 were compared by microarray CyanoChip (Takrara bio.). Experiments were performed three times with biologically independent RNA. Total RNAs from three independent wild-type (GT) and three independent ntcA-overexpressing strains were differently labeled by Cy3 or Cy5, followed by hybridization on CyanoChip.
Project description:NtcA regulates primary in a unicelluar cyanobacterium Synechocystis sp. PCC6803. We constructed an ntcA-overexpressing strain, named NOX10, by introducing the ntcA genes fusing psbAII promoter by homologous recombination. The transcript profiles of parental wild-type strain GT and NOX10 were compared by microarray CyanoChip (Takrara bio.). Experiments were performed two times with biologically independent RNA.
Project description:NtcA regulates primary in a unicelluar cyanobacterium Synechocystis sp. PCC6803. We constructed an ntcA-overexpressing strain, named NOX10, by introducing the ntcA genes fusing psbAII promoter by homologous recombination. The transcript profiles of parental wild-type strain GT and NOX10 were compared by microarray CyanoChip (Takrara bio.). Experiments were performed three times with biologically independent RNA.
Project description:Cyanobacteria are oxygenic photoautotrophs responsible for a substantial proportion of nitrogen fixation and primary production in the hydrosphere. Non-nitrogen fixing cyanobacteria, such as Synechocystis sp. PCC 6803, depend of the availability of nitrogenized species to survive. Therefore, an intricate regulatory network around the transcriptional factor NtcA maintains the homeostasis of nitrogen in these organisms. The mechanisms controlling NtcA activity are well understood but a comprehensive study of its regulon is missing in Synechocystis. To define NtcA regulon during the early stage of nitrogen starvation, we have performed chromatin immunoprecipitation followed by sequencing (ChiP-seq), in parallel with genome level transcriptome analysis (RNA-seq). By combining both methods we assigned 51 activated and 28 repressed genes directly by NtcA. Most of direct targets included genes involved in nitrogen and carbon metabolism and photosynthesis. NtcA regulon also included 8 ncRNAs, of which ncr0710, Syr6 and NsiR7 were experimentally validated. Intriguingly, we identified several NtcA intragenic binding sites suggesting that NtcA can modulate transcriptional expression by binding along the whole transcript and not only in the promoter region as previously though. Finally, the transcriptional implication of PipX was analyzed in some NtcA-targets genes, revealing that PipX assists NtcA in the global nitrogen regulation in Synechocystis.
