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The impact of the cyanobacterial carbon‐regulator protein SbtB and of the second messengers cAMP and c‐di‐AMP on CO 2 ‐dependent gene expression
Author(s) -
Mantovani Oliver,
Reimann Viktoria,
Haffner Michael,
Herrmann Felix Philipp,
Selim Khaled A.,
Forchhammer Karl,
Hess Wolfgang R.,
Hagemann Martin
Publication year - 2022
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.18094
Subject(s) - mutant , synechocystis , second messenger system , transcriptome , gene , biology , regulator , gene expression , acclimatization , cyanobacteria , metabolome , response regulator , regulation of gene expression , messenger rna , biochemistry , wild type , microbiology and biotechnology , genetics , signal transduction , bacteria , metabolite
Summary The amount of inorganic carbon (C i ) fluctuates in aquatic environments. Cyanobacteria evolved a C i ‐concentrating mechanism (CCM) that is regulated at different levels. The regulator SbtB binds to the second messengers cAMP or c‐di‐AMP and is involved in acclimation to low C i (LC) in Synechocystis sp. PCC 6803. Here, we investigated the role of SbtB and of associated second messengers at different C i conditions. The transcriptome of wild‐type (WT) Synechocystis and the Δ sbtB mutant were compared with Δ cya1 , a mutant defective in cAMP production, and Δ dacA , a mutant defective in generating c‐di‐AMP. A defined subset of LC‐regulated genes in the WT was already changed in Δ sbtB under high C i (HC) conditions. This response of Δ sbtB correlated with a diminished induction of many CCM‐associated genes after LC shift in this mutant. The Δ cya1 mutant showed less deviation from WT, whereas Δ dacA induced CCM‐associated genes under HC. Metabolome analysis also revealed differences between the strains, whereby Δ sbtB showed slower accumulation of 2‐phosphoglycolate and Δ dacA differences among amino acids compared to WT. Collectively, these results indicate that SbtB regulates a subset of LC acclimation genes while c‐di‐AMP and especially cAMP appear to have a lesser impact on gene expression under different C i availabilities.