著者

Ryoji Koike Yuichi Kato Shigeki Ehira

出版者

Applied Microbiology, Molecular and Cellular Biosciences Research Foundation

雑誌

The Journal of General and Applied Microbiology (ISSN:00221260)

巻号頁・発行日

pp.2019.10.002, (Released:2019-12-17)

参考文献数

26

被引用文献数

2

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Cyanobacteria are a morphologically and physiologically diverse group of bacteria, which contains unicellular and multicellular filamentous strains. Some filamentous cyanobacteria, such as Anabaena sp. strain PCC 7120, form a differentiated cell called a heterocyst. The heterocyst is a specialized cell for nitrogen fixation and is differentiated from a vegetative cell in response to depletion of combined nitrogen in the medium. In Anabaena PCC 7120, it has been demonstrated that hetR, which encodes a transcriptional regulator, is necessary and sufficient for heterocyst differentiation. However, comprehensive genomic analysis of cyanobacteria has shown that hetR is present in non-heterocyst-forming cyanobacteria. Almost all filamentous cyanobacteria have hetR, but unicellular cyanobacteria do not. In this study, we conducted genetic and biochemical analyses of hetR (NIES39_C03480) of the non-heterocyst-forming cyanobacterium Arthrospira platensis NIES-39. HetR of A. platensis was able to complement the hetR mutation in Anabena PCC 7120 and recognized the same DNA sequence as Anabaena HetR. A search of the A. platensis genome revealed the HetR-recognition sequence within the promoter region of NIES39_O04230, which encodes a protein of unknown function. Expression from the NIES39_O04230 promoter could be suppressed by HetR in Anabaena PCC 7120. These data support the conclusion that NIES39_O04230 is regulated by HetR in A. platensis NIES-39.