Project description:The whole regulon of the LTTR All3953 was determined at 3 h after Ci deficiency in the cyanobacterium Anabaena sp. PCC 7120 by ChIP-Seq analysis. A TAP-tagged version of the protein was used for the chromatin immunoprecipitation. A total of 142 peaks were found, mainly located in the chromosome of Anabaena.
Project description:In order to examine the response of Anabaena sp. PCC 7120 to an infection of the Cyanophage A1, we have used customized microarrays to identify genes potentially up- or downregulated by the infection. For this we compared cell culture before and after infection.
Project description:To examine Alr3614 influence on the expression of Anabaena sp. PCC 7120, we have used customized microarrays to identify genes potentially regulated by this short DNA-binding protein. We compared the expression of an Alr3614-deletion strain with an Alr3614-complementation strain.
Project description:Here, we report the comparison of transcriptomes of Anabaena sp. PCC7120 and a FurC-overexpressing derivative strain grown under standard conditions (BG11) and after 48 hours of nitrogen step-down (BG110). Anabaena sp PCC7120 is a cyanobacterium that differentiates specialized nitrogen-fixing cells called heterocysts. Our data suggests that FurC directly controls the regulation of heterocyst differentiation and nitrogen fixation in this cyanobacterium. In addition, we found that FurC is also clearly involved in the regulation of several genes belonging to different functional categories, such as iron metabolism, photosynthesis and regulatory functions.
Project description:How new functions emerge as genes diversify during evolution is an important question in biology. cyclic adenosine monophosphate receptor protein (CRP) -type transcription factors are widespread in bacteria, often with several members coexisting in the same organism. How do they achieve functional specificity with highly conserved structures? In the filamentous cyanobacterium Nostoc/Anabaena sp. PCC 7120, both NtcA and DevH belong to the CRP family, yet DevH is essential while NtcA is not. Together with previously published data, we demonstrate here that ntcA and devH mutually and positively regulate each other for enhanced expression. Furthermore, NtcA and DevH share a common consensus DNA binding site, and both of them exert global regulation functions for metabolism, photosynthesis and cell development. We show that compared to NtcA, DevH achieved functional specificity and essentiality by structural innovations and increased cellular concentrations, leading to a stronger and broader regulatory function independent of allosteric control. Based on our data, we propose a model on how these two conserved transcription factors provide both overlapping and distinct regulatory functions, to better coordinate transcriptional activities under different conditions. This study constitutes an example illustrating how functional divergence can be achieved following gene diversification of transcription factors, leading to increased complexity in gene regulation networks.