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Updated: Aug 8, 2026

Measuring Carbon-based Contaminant Mineralization Using Combined CO2 Flux and Radiocarbon Analyses
Published on: October 21, 2016
Sensing inorganic carbon: CO2 and HCO3-
1Plant Research Unit, University of Dundee at SCRI, Scottish Crop Research Institute, Invergowrie, Dundee, Scotland DD2 5DA, UK. j.a.raven@dundee.ac.uk
Cyanobacterial adenylyl cyclases are activated by carbon dioxide (CO2), not bicarbonate (HCO3-), challenging previous assumptions. This finding impacts understanding of inorganic carbon sensing in cellular regulation.
Area of Science:
- Biochemistry
- Cellular Biology
- Microbiology
Background:
- Proteins catalyzing inorganic carbon reactions are well-understood regarding CO2/HCO3- interaction.
- Limited information exists on which inorganic carbon species are recognized by sensing proteins.
Discussion:
- Hammer and colleagues demonstrate cyanobacterial adenylyl cyclases are activated by CO2.
- This contrasts with the previous belief that bicarbonate (HCO3-) was the activating species.
- Differences in sensing outcomes arise when CO2 and HCO3- are not in equilibrium, such as in compartments lacking carbonic anhydrase.
Key Insights:
- Cyanobacterial adenylyl cyclases specifically recognize and are activated by CO2.
- Cellular regulation by inorganic carbon sensing can differ significantly based on the recognized species (CO2 vs. HCO3-).
- Non-equilibrium conditions of inorganic carbon species impact regulatory outcomes.
Outlook:
- Further research into the precise mechanisms of inorganic carbon sensing by various proteins.
- Investigating the physiological relevance of CO2-specific sensing in different cellular compartments.
- Exploring how environmental factors like pH and temperature influence inorganic carbon sensing and downstream effects.
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