Expression of the Cyanobacterial FoF1 ATP Synthase Regulator AtpΘ Depends on Small DNA-Binding Proteins and Differential mRNA Stability
ABSTRACT FoF1 ATP synthases produce ATP, the universal biological energy source. ATP synthase complexes on cyanobacterial thylakoid membranes use proton gradients generated either by photosynthesis or respiration. AtpΘ is an ATP synthase regulator in cyanobacteria which is encoded by the gene atpT....
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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American Society for Microbiology
2022-06-01
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| Series: | Microbiology Spectrum |
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| Online Access: | https://journals.asm.org/doi/10.1128/spectrum.02562-21 |
| _version_ | 1818255494495600640 |
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| author | Kuo Song Martin Hagemann Jens Georg Sandra Maaß Dörte Becher Wolfgang R. Hess |
| author_facet | Kuo Song Martin Hagemann Jens Georg Sandra Maaß Dörte Becher Wolfgang R. Hess |
| author_sort | Kuo Song |
| collection | DOAJ |
| description | ABSTRACT FoF1 ATP synthases produce ATP, the universal biological energy source. ATP synthase complexes on cyanobacterial thylakoid membranes use proton gradients generated either by photosynthesis or respiration. AtpΘ is an ATP synthase regulator in cyanobacteria which is encoded by the gene atpT. AtpΘ prevents the hydrolysis of ATP (reverse reaction) that otherwise would occur under unfavorable conditions. In the cyanobacterium Synechocystis sp. PCC 6803, AtpΘ is expressed maximum in darkness but at very low levels under optimum phototrophic growth conditions or in the presence of glucose. DNA coimmunoprecipitation experiments followed by mass spectrometry identified the binding of the two transcriptional regulators cyAbrB1 and cyAbrB2 to the promoter and the histone-like protein HU to the 5’UTR of atpT. Analyses of nucleotide substitutions in the promoter and GFP reporter assays identified a functionally relevant sequence motif resembling the HLR1 element bound by the RpaB transcription factor. Electrophoretic mobility shift assays confirmed interaction of cyAbrB1, cyAbrB2, and RpaB with the promoter DNA. However, overall the effect of transcriptional regulation was comparatively low. In contrast, atpT transcript stabilities differed dramatically, half-lives were 1.6 min in the light, 33 min in the dark and substantial changes were observed if glucose or DCMU were added. These findings show that transcriptional control of atpT involves nucleoid-associated DNA-binding proteins, positive regulation through RpaB, while the major effect on the condition-dependent regulation of atpT expression is mediated by controlling mRNA stability, which is related to the cellular redox and energy status. IMPORTANCE FoF1 ATP synthases produce ATP, the universal biological energy source. Under unfavorable conditions, ATP synthases can operate in a futile reverse reaction, pumping protons while ATP is used up. Cyanobacteria perform plant-like photosynthesis, but they cannot use the same mechanism as plant chloroplasts to inhibit ATP synthases during the night because respiratory and photosynthetic complexes are both located in the same membrane system. AtpΘ is a small protein encoded by the gene atpT in cyanobacteria that can prevent the ATP synthase reverse reaction (ATPase activity). Here we found that three transcription factors contribute to the regulation of atpT expression. However, the control of mRNA stability was identified as the major regulatory process governing atpT expression. Thus, it is the interplay between transcriptional and posttranscriptional regulation that position the AtpΘ-based regulatory mechanism within the context of the cellular redox and energy balance. |
| first_indexed | 2024-12-12T17:12:45Z |
| format | Article |
| id | doaj.art-a74b5161524b4472872b942187313f8a |
| institution | Directory Open Access Journal |
| issn | 2165-0497 |
| language | English |
| last_indexed | 2024-12-12T17:12:45Z |
| publishDate | 2022-06-01 |
| publisher | American Society for Microbiology |
| record_format | Article |
| series | Microbiology Spectrum |
| spelling | doaj.art-a74b5161524b4472872b942187313f8a2022-12-22T00:17:51ZengAmerican Society for MicrobiologyMicrobiology Spectrum2165-04972022-06-0110310.1128/spectrum.02562-21Expression of the Cyanobacterial FoF1 ATP Synthase Regulator AtpΘ Depends on Small DNA-Binding Proteins and Differential mRNA StabilityKuo Song0Martin Hagemann1Jens Georg2Sandra Maaß3Dörte Becher4Wolfgang R. Hess5Genetics and Experimental Bioinformatics, Faculty of Biology, University of Freiburg, Freiburg, GermanyPlant Physiology Department, Institute of Biological Sciences, University of Rostock, Rostock, GermanyGenetics and Experimental Bioinformatics, Faculty of Biology, University of Freiburg, Freiburg, GermanyDepartment of Microbial Proteomics, Institute of Microbiology, Center for Functional Genomics of Microbes, University of Greifswald, Greifswald, GermanyDepartment of Microbial Proteomics, Institute of Microbiology, Center for Functional Genomics of Microbes, University of Greifswald, Greifswald, GermanyGenetics and Experimental Bioinformatics, Faculty of Biology, University of Freiburg, Freiburg, GermanyABSTRACT FoF1 ATP synthases produce ATP, the universal biological energy source. ATP synthase complexes on cyanobacterial thylakoid membranes use proton gradients generated either by photosynthesis or respiration. AtpΘ is an ATP synthase regulator in cyanobacteria which is encoded by the gene atpT. AtpΘ prevents the hydrolysis of ATP (reverse reaction) that otherwise would occur under unfavorable conditions. In the cyanobacterium Synechocystis sp. PCC 6803, AtpΘ is expressed maximum in darkness but at very low levels under optimum phototrophic growth conditions or in the presence of glucose. DNA coimmunoprecipitation experiments followed by mass spectrometry identified the binding of the two transcriptional regulators cyAbrB1 and cyAbrB2 to the promoter and the histone-like protein HU to the 5’UTR of atpT. Analyses of nucleotide substitutions in the promoter and GFP reporter assays identified a functionally relevant sequence motif resembling the HLR1 element bound by the RpaB transcription factor. Electrophoretic mobility shift assays confirmed interaction of cyAbrB1, cyAbrB2, and RpaB with the promoter DNA. However, overall the effect of transcriptional regulation was comparatively low. In contrast, atpT transcript stabilities differed dramatically, half-lives were 1.6 min in the light, 33 min in the dark and substantial changes were observed if glucose or DCMU were added. These findings show that transcriptional control of atpT involves nucleoid-associated DNA-binding proteins, positive regulation through RpaB, while the major effect on the condition-dependent regulation of atpT expression is mediated by controlling mRNA stability, which is related to the cellular redox and energy status. IMPORTANCE FoF1 ATP synthases produce ATP, the universal biological energy source. Under unfavorable conditions, ATP synthases can operate in a futile reverse reaction, pumping protons while ATP is used up. Cyanobacteria perform plant-like photosynthesis, but they cannot use the same mechanism as plant chloroplasts to inhibit ATP synthases during the night because respiratory and photosynthetic complexes are both located in the same membrane system. AtpΘ is a small protein encoded by the gene atpT in cyanobacteria that can prevent the ATP synthase reverse reaction (ATPase activity). Here we found that three transcription factors contribute to the regulation of atpT expression. However, the control of mRNA stability was identified as the major regulatory process governing atpT expression. Thus, it is the interplay between transcriptional and posttranscriptional regulation that position the AtpΘ-based regulatory mechanism within the context of the cellular redox and energy balance.https://journals.asm.org/doi/10.1128/spectrum.02562-21FoF1 ATP synthaseAtpΘcyanobacteriacyAbrBstranscriptional regulationRNA stability |
| spellingShingle | Kuo Song Martin Hagemann Jens Georg Sandra Maaß Dörte Becher Wolfgang R. Hess Expression of the Cyanobacterial FoF1 ATP Synthase Regulator AtpΘ Depends on Small DNA-Binding Proteins and Differential mRNA Stability Microbiology Spectrum FoF1 ATP synthase AtpΘ cyanobacteria cyAbrBs transcriptional regulation RNA stability |
| title | Expression of the Cyanobacterial FoF1 ATP Synthase Regulator AtpΘ Depends on Small DNA-Binding Proteins and Differential mRNA Stability |
| title_full | Expression of the Cyanobacterial FoF1 ATP Synthase Regulator AtpΘ Depends on Small DNA-Binding Proteins and Differential mRNA Stability |
| title_fullStr | Expression of the Cyanobacterial FoF1 ATP Synthase Regulator AtpΘ Depends on Small DNA-Binding Proteins and Differential mRNA Stability |
| title_full_unstemmed | Expression of the Cyanobacterial FoF1 ATP Synthase Regulator AtpΘ Depends on Small DNA-Binding Proteins and Differential mRNA Stability |
| title_short | Expression of the Cyanobacterial FoF1 ATP Synthase Regulator AtpΘ Depends on Small DNA-Binding Proteins and Differential mRNA Stability |
| title_sort | expression of the cyanobacterial fof1 atp synthase regulator atpθ depends on small dna binding proteins and differential mrna stability |
| topic | FoF1 ATP synthase AtpΘ cyanobacteria cyAbrBs transcriptional regulation RNA stability |
| url | https://journals.asm.org/doi/10.1128/spectrum.02562-21 |
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