Heterologous expression in <i>E. coli</i> reveals the bicarbonate transporter BicA2 drives carbon uptake in marine <i>Prochlorococcus</i> spp
大腸菌での異種発現により、海洋プロクロロコッカス属における重炭酸輸送体BicA2が炭素取り込みを駆動することを解明 (AI 翻訳)
Loraine M. Rourke, Caitlin S. Byrt, G Dean Price, Benedict M. Long
🤖 gxceed AI 要約
日本語
本研究は、海洋性シアノバクテリアProchlorococcusにおいて、重炭酸輸送体BicA2がNa⁺依存的な低親和性HCO₃⁻輸送を行うことを初めて機能的に実証した。これにより、本種のCO₂濃縮機構の未解明要素が明らかとなり、地球規模の炭素循環への理解が深まる。
English
This study provides the first functional evidence of bicarbonate transport in Prochlorococcus, demonstrating that BicA2 is a low-affinity, Na⁺-dependent HCO₃⁻ transporter. It reveals evolutionary plasticity in CCM components and reshapes understanding of carbon acquisition in the most abundant marine phototroph, with implications for global carbon cycles.
Unofficial AI-generated summary based on the public title and abstract. Not an official translation.
📝 gxceed 編集解説 — Why this matters
In the global GX context
This fundamental discovery advances understanding of marine carbon fixation, which underpins climate models and nature-based carbon removal strategies relevant to global decarbonization efforts.
👥 読者別の含意
🔬研究者:Provides mechanistic insight into cyanobacterial CCMs, informing models of global carbon cycling and potential biotechnological applications for carbon capture.
📄 Abstract（原文）
Abstract The widespread oceanic cyanobacterial Prochlorococcus genus is a major contributor to global carbon fixation, yet mechanisms enabling this lineage to elevate intracellular inorganic carbon as a substrate for photosynthesis remain unresolved. Cyanobacterial CO 2 concentrating mechanisms typically rely on membrane-bound bicarbonate (HCO - ) transporters SbtA1, SbtA2, BicA and BCT1, and CO 2 -to-HCO 3 - conversion uptake systems (CO 2 pumps; NDH-I 3 and NDH-I 4 ), to elevate a cellular HCO 3 - pool for use by Rubisco-containing carboxysomes. Evidence suggests Prochlorococcus harbours carboxysomes with a low-CO 2 -specificity Rubisco, implying a functional CCM dependent on active HCO 3 - uptake. However, canonical CO 2 pumps are absent, leaving distant HCO - transporter homologues, BicA2 and SbtA2, as prime candidates for HCO 3 - transport in this group. Yet these have not been functionally characterised. Here we demonstrate that BicA2 from P. marinus CCMP1375 mediates Na + -dependent HCO 3 - uptake in E. coli , while BicA2 from P. marinus CCMP1986 is inactive in its native form but acquired transport function through a single amino acid substitution during adaptive laboratory evolution. These findings confirm BicA2 as a low-affinity, Na + -dependent bicarbonate transporter with variable flux, revealing a previously uncharacterized CCM component in Prochlorococcus . This mechanistic insight reshapes our understanding of carbon acquisition strategies in the most abundant photosynthetic organism on Earth and highlights evolutionary plasticity in transporter function with implications for global biogeochemical cycles. Highlight This study provides the first mechanistic evidence of bicarbonate transport in Prochlorococcus , revealing functional and evolutionary flexibility in its CO 2 -concentrating mechanism components and reshaping our understanding of carbon acquisition in the most abundant marine photoautotroph.
🔗 Provenance — このレコードを発見したソース
- openalex https://doi.org/10.64898/2026.05.23.727450first seen 2026-06-17 05:52:41 · last seen 2026-06-17 07:14:14
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