Adenylate cyclase in Arthrospira platensis responds to light through transcription

Cyclic 3′,5′ adenosine monophosphate (cAMP) is a ubiquitous signaling molecule, but its role in higher plants was in doubt due to its very low concentration. In this study we wanted to look at the flux of cAMP in response to light in algae, considered to be the more primitive form of photosynthetic organisms. While it did not fluctuate very much in the tested green algae, in the cyanobacterium Arthrospira platensis its level was closely linked to exposure to light. The expression from cyaC, the major isoform of adenylate cyclase was strongly influenced by exposure of the cells to light. There was about 300 fold enhancement of cyaC transcripts in cells exposed to light compared to the transcripts in cells in the dark. Although post-translational regulation of adenylate cyclase activity has been widely known, our studies suggest that transcriptional control could also be an important aspect of its regulation in A. platensis. •The concentration of cAMP showed almost ten fold variation within a day in the cyanobacterium Arthrospira platensis.•The concentration of cAMP in A. platensis was strongly influenced by their exposure to light.•Compared to adenylate cyclases cyaA and cyaG, the transcript of cyaC showed the maximum light dependent modulation.•Light quanta was an important factor in the induction of cyaC transcription.