[CO2] Alters Cyanobacterial Carboxysome Encapsulation and Redox State

[CO2] Alters Cyanobacterial Carboxysome Encapsulation and Redox State | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article [CO 2 ] Alters Cyanobacterial Carboxysome Encapsulation and Redox State Clair Huffine, Catherine Fontana, Rosanna Garris, Colin Sempeck, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4814625/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted You are reading this latest preprint version Abstract Responsible for fixing 25% of CO2 globally, cyanobacteria use carboxysomes to house their CO2 fixing machinery. The formation and permeability of the proteinaceous shell of carboxysomes is an area of active study. While necessary in air (0.04% CO2), the shell is not required when cyanobacteria are in high CO2 levels representative of early Earth. To understand how the carboxysome shell responds to increased CO2 conditions, we used a Grx1-roGFP2 redox sensor and single cell timelapse fluorescence microscopy to track subcellular redox states of Synechococcus sp. PCC 7002. Comparing different levels of compartmentalization, we targeted the cytosol, a shell-less carboxysomal assembly intermediate called procarboxysomes, and carboxysomes. Carboxysome redox state was dynamic, and, under 3% CO2 conditions, procarboxysome-like structures formed which were only partially encapsulated and exposed the carboxysome contents to the cytosol. This work expands the adaptability of carboxysomes to environmental conditions and builds understanding of the selective forces that initially drove carboxysome evolution. Biological sciences/Microbiology/Bacteriology Biological sciences/Microbiology/Cellular microbiology Carboxysome Procarboxysome Cyanobacteria Redox CO2 Modulation roGFP Climate Change Photosynthesis Full Text Additional Declarations Yes there is potential Competing Interest. J.C.C. was a co-founder and holds equity in Prometheus Materials. All other authors declare they have no other competing interests. Supplementary Files SupplementaryMovie1Lcom.avi Supplementary Movie 1 SupplementaryMovie2LRatiocom.avi Supplementary Movie 2 SupplementaryMovie3LHcom.avi Supplementary Movie 3 SupplementaryMovie4LHRatiocom.avi Supplementary Movie 4 SupplementaryMovie5HLcom.avi Supplementary Movie 5 SupplementaryMovie6HLRatiocom.avi Supplementary Movie 6 SupplementalMovie7roGFPairTomo.avi Supplementary Movie 7 SupplementalMovie8dCcmO3CO2Tilt.avi Supplementary Movie 8 SupplementalMovie9WTAirTilt.avi Supplementary Movie 9 SupplementalMovie10roGFP3CO2Tomo.avi Supplementary Movie 10 Cite Share Download PDF Status: Under Review Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-4814625","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":593086798,"identity":"b36d5c5b-f3fe-4286-8a42-5966f51a2331","order_by":0,"name":"Clair 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