Liquid-liquid phase separation around a membrane: Investigating the assembly of the pyrenoid around the thylakoid membrane in Chlamydomonas reinhardtii
Final Report Abstract
The CO2-concentrating mechanism (CCM) found in algae has the potential to improve crop productivity if successfully introduced into crops plant. At the centre of the algal CCM is a liquid-liquid phase separated Rubisco condensate within the chloroplast, the pyrenoid. In the pyrenoid, Rubisco is actively supplied with CO2, which enters the pyrenoid via a specialised, tubular region of the thylakoid membrane, called pyrenoid tubules. In this project, we investigated the biogenesis of the pyrenoid tubules in the green model alga Chlamydomonas reinhardtii. Through a screening of target proteins, identified through literature and bioinformatic analysis, for knock-out phenotype and intracellular localisation, we identified the dynamin-like protein Fzl to play a role in the tubule biogenesis. Growth of a Fzl knock-out is strongly reduced under low CO2 conditions and Fzl accumulates at the pyrenoid tubules. Multiple pyrenoids in the Fzl knock-out line indicate further a role in pyrenoid tubule biogenesis, however its exact role needs to be elucidated further. Furthermore, the underlying fundamental principles of pyrenoid assembly were used in this project to guide the engineering of a synthetic CCM system. Rubisco condensates were successfully tethered to liposomes and a CO2 transport system was established in liposomes to mimic the algal CCM in vitro.
Publications
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A phase-separated CO2-fixing pyrenoid proteome determined by TurboID in Chlamydomonas reinhardtii. The Plant Cell, 35(9), 3260-3279.
Lau, Chun Sing; Dowle, Adam; Thomas, Gavin H.; Girr, Philipp & Mackinder, Luke C. M.
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The role of BST4 in the pyrenoid ofChlamydomonas reinhardtii. Cold Spring Harbor Laboratory.
Adler, Liat; Lau, Chun Sing; Shaikh, Kashif M.; Maldegem, Kim A. van; Payne-Dwyer, Alex L.; Lefoulon, Cecile; Girr, Philipp; Atkinson, Nicky; Barrett, James; Emrich-Mills, Tom Z.; Dukic, Emilija; Blatt, Michael R.; Leake, Mark C.; Peltier, Gilles; Spetea, Cornelia; Burlacot, Adrien; McCormick, Alistair J.; Mackinder, Luke C. M. & Walker, Charlotte E.
