The Phase Separation Underlying the Pyrenoid-based Microalgal Rubisco Supercharger

Overview

Journal Nat Commun

Specialty Biology

Date 2018 Dec 1

PMID 30498228

Citations 53

Authors

Tobias Wunder

Steven Le Hung Cheng

Soak-Kuan Lai

Hoi-Yeung Li

Oliver Mueller-Cajar

Affiliations

Soon will be listed here.

Abstract

The slow and promiscuous properties of the CO-fixing enzyme Rubisco constrain photosynthetic efficiency and have prompted the evolution of powerful CO concentrating mechanisms (CCMs). In eukaryotic microalgae a key strategy involves sequestration of the enzyme in the pyrenoid, a liquid non-membranous compartment of the chloroplast stroma. Here we show using pure components that two proteins, Rubisco and the linker protein Essential Pyrenoid Component 1 (EPYC1), are both necessary and sufficient to phase separate and form liquid droplets. The phase-separated Rubisco is functional. Droplet composition is dynamic and components rapidly exchange with the bulk solution. Heterologous and chimeric Rubiscos exhibit variability in their tendency to demix with EPYC1. The ability to dissect aspects of pyrenoid biochemistry in vitro will permit us to inform and guide synthetic biology ambitions aiming to engineer microalgal CCMs into crop plants.

Citing Articles

In-cell Structure and Variability of Pyrenoid Rubisco.

Elad N, Hou Z, Dumoux M, Ramezani A, Perilla J, Zhang P bioRxiv. 2025; .

PMID: 40060630 PMC: 11888406. DOI: 10.1101/2025.02.27.640608.

Knowledge of microalgal Rubiscos helps to improve photosynthetic efficiency of crops.

Zhu T, Ning P, Liu Y, Liu M, Yang J, Wang Z Planta. 2025; 261(4):78.

PMID: 40042639 DOI: 10.1007/s00425-025-04645-w.

Hornworts reveal a spatial model for pyrenoid-based CO-concentrating mechanisms in land plants.

Robison T, Oh Z, Lafferty D, Xu X, Villarreal J, Gunn L Nat Plants. 2025; 11(1):63-73.

PMID: 39753956 DOI: 10.1038/s41477-024-01871-0.

SAGA1 and MITH1 produce matrix-traversing membranes in the CO-fixing pyrenoid.

Hennacy J, Atkinson N, Kayser-Browne A, Ergun S, Franklin E, Wang L Nat Plants. 2024; 10(12):2038-2051.

PMID: 39548241 PMC: 11649565. DOI: 10.1038/s41477-024-01847-0.

A promiscuous mechanism to phase separate eukaryotic carbon fixation in the green lineage.

Barrett J, Naduthodi M, Mao Y, Degut C, Musial S, Salter A Nat Plants. 2024; 10(11):1801-1813.

PMID: 39384944 PMC: 11570498. DOI: 10.1038/s41477-024-01812-x.

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