Developing de novo architectures of photosynthetic complexes for the control of photocurrent output from reaction centres.

Biography

I am interested in the mechanisms of light harvesting and carbon sequestration in living organisms, and how these might be applied to solar and carbon capture technology and efforts to improve photosynthetic efficiency in crop plants. After completing an MSc in biochemistry at the University of Manchester in 2016 I was employed as a research technician at the University of York to work on the mechanisms of carbon-concentration in green algae, with a focus on expanding known protein interactors by high-throughput cloning and screening. In 2018 I joined the Department of Molecular Biology and Biotechnology at the University of Sheffield as a PhD student with the Johnson and Hunter labs. My work involves molecular biology, light microscopy and scanning probe imaging techniques.

My Project

I work on the dynamics, protein composition and ultrastructure of thylakoid membranes in plants and algae. My project is split between work on visualising the protein composition of the thylakoid membrane using light and atomic force microscopy, and work towards improving our understanding of the mechanisms of cyclic electron flow in photosynthesis.

Photosynthetic eukaryotes continuously rearrange the structure and composition of their thylakoid membranes to regulate photosynthetic efficiency. These membranes can have highly heterogeneous and dynamic protein compositions, and they are often segregated into spatially distinct regions. The forces driving changes in composition, as well as those maintaining the segregation of compositionally distinct regions of thylakoids are yet not fully understood, and there are still interesting questions about why these regions have the composition that they do. Atomic force microscopy (AFM) has the ability to map the topographical features of thylakoid membranes with nanometre resolution. Using AFM, my project will attempt to improve our understanding of the differences in protein composition between thylakoid regions in plants and algae and how they affect regulation of photosynthetic efficiency in these organisms.

On a mechanistic scale, questions remain about the path of electron transfer between membrane proteins in cyclic electron flow, which is a form of photosynthetic electron transfer that produces ATP without reducing NADP. Some of these questions can be addressed in green algae, which are more amenable to genetic modification than higher plants. An improved understanding of the mechanisms of cyclic electron flow has implications for our ability to enhance photosynthetic efficiency in crop plants to meet the challenges of increasing desertification of arable land and a growing population in the coming century.

Project Aims

To explore structural and compositional differences between regions of thylakoid membranes within and between higher plants and algae using atomic force microscopy.

To develop and in vivo fluorescent probe of super-complex formation in green algae, with a view to assessing the functional necessity of a cyclic electron flow-associated super-complex of thylakoid membrane proteins.

To probe cyclic electron flow by introducing synthetic proteins to disrupt electron transfer between photosystem I and cytochrome b6f in green algae.