Diatoms perform ~20% of global primary production, playing a pivotal role in global carbon and nutrient cycling. At the heart of diatom carbon-fixation is the pyrenoid – a biomolecular condensate of the CO2-fixing enzyme Rubisco. The pyrenoid turbocharges photosynthesis by concentrating and releasing CO2 in specialized thylakoid membranes that traverse the Rubisco dense matrix of the pyrenoid.
Despite its global fundamental importance, very little is known about the diatom pyrenoid. Broader, understanding algal carbon fixation and our ability to engineer it has the potential to improve photosynthesis to enhance crop yields and boost biological based carbon capture methods.
In this PhD project the selected student will investigate the specialized thylakoid membranes that traverse the diatom pyrenoid. They will explore the formation, protein composition and function of these membranes. They will investigate how Rubisco condensates are attached to these membranes and how large protein assemblies influence membrane properties.
To do this they will use a recently established diatom molecular toolkit to localize candidate proteins to understand their spatial distribution within the pyrenoid. In parallel, CRISPR/Cas will be used to knock out target genes to understand functional and structural importance. Biochemical approaches combined with CryoEM will be used to link protein structure to function and cryoET will be applied to understand in-situ structural changes. All relevant training will be provided.
One candidate will be selected to work on a project proposal. They will then compete at interview, with up to 7 other candidates, for one of up to four Sainsbury PhD Studentships. Interviews will be held in London on 13th January, 2023. It is expected that the studentship holder spends six months during the 3rd or 4th year at another university/institute to gain additional experience. Please note that students are not normally allowed to apply to the institution where they carried out their undergraduate degree.
Funding Notes
Enhanced four-year postgraduate studentships, starting in October 2023, will again be awarded by the Gatsby Charitable Foundation. The maintenance stipend in the first year will be £22,407 (to increase by 4% annually). In addition to this, there is an annual payment of £5,500 for department laboratory fees, and £700 for books, conferences and travel. Tuition fees are also paid by the Foundation.
Application:
Interested candidates from any background and nationality are encouraged to contact Luke Mackinder (luke.mackinder@york.ac.uk) with their CV and a brief statement of interest (maximum 500 words).
Deadline for applications Sunday, November 20, 2022
References
Barrett J, Girr P, Mackinder LCM (2021) Pyrenoids: CO2-fixing phase separated liquid organelles. Biochimica et Biophysica Acta (BBA) – Molecular Cell Research. https://doi.org/10.1016/j.bbamcr.2021.118949.
Onyou N, Grouneva I, Mackinder LCM (2022) Endogenous GFP tagging in the diatom Thalassiosira pseudonana. bioRxiv 2022.09.30.510313; doi: https://doi.org/10.1101/2022.09.30.510313
Mackinder LCM, Chen C, Leib R, Patena W, Blum SR, Rodman M, Ramundo S, Adams C, Jonikas MC (2017). A spatial interactome reveals the protein organization of the algal CO2 concentrating mechanism. Cell 171:133-147. https://doi.org/10.1016/j.cell.2017.08.044