Nghiem D Nguyen, Loraine M Rourke, G Dean Price, Benedict M Long
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引用次数: 0
Abstract
Since their discovery as rubisco-containing compartments more than 50 years ago, significant breakthroughs have advanced our understanding of carboxysome structure and function, and their centrality to cyanobacterial CO2 concentrating mechanisms (CCMs). Within CCMs, cellular bicarbonate (HCO3-) is actively accumulated and maintained by a suite of HCO3- transporters and CO2-to-HCO3- conversion pumps to support carboxysome function. This elevation of cellular HCO3- is indispensable for carboxysome action, as they rely entirely on concentrated HCO3- to generate internal CO2 for rubisco. This review traces the historical progression of carboxysome research, from early structural observations to modern insights into their biogenesis, internal organization, and function. We explore the evolutionary trajectory of carboxysomes, hypothesising why terrestrial plants, despite sharing a common ancestor with cyanobacteria, lack these microcompartments. Despite their absence from plants, carboxysomes are now being engineered into plant chloroplasts as part of efforts to improve photosynthetic performance. We also address the physiological implications of carboxysome gas permeability, the role of oxygenation, and the need for in vitro assays to assess carboxysome functionality in engineered systems. We discuss the challenges of reconstructing functional carboxysomes in heterologous systems, particularly the need for HCO3- accumulation. Finally, we consider the future of carboxysomes, including their use as modular platforms for carbon fixation and novel catalytic functions and their potential forward evolutionary trajectories. By synthesizing historical, mechanistic, and applied perspectives, this review highlights both the possibilities and limitations of rubisco encapsulation in heterologous systems.
期刊介绍:
The Journal of Experimental Botany publishes high-quality primary research and review papers in the plant sciences. These papers cover a range of disciplines from molecular and cellular physiology and biochemistry through whole plant physiology to community physiology.
Full-length primary papers should contribute to our understanding of how plants develop and function, and should provide new insights into biological processes. The journal will not publish purely descriptive papers or papers that report a well-known process in a species in which the process has not been identified previously. Articles should be concise and generally limited to 10 printed pages.