Past ECR Seminar Speakers

September 2026 speakers:

Mary Tozer from the lab of Doreen Cantrell (University of Dundee), who will present:

"Glucose Availability Controls Selective Protein Turnover in Effector CD8 T Cells"

and

Katherine Fenn from the lab of Neil Ranson/Sheena Radford (University of Leeds) who will present:

"BAM-BepA complexes in outer membrane protein quality control"

A Bit About Mary:

Mary is originally from London and currently based at the University of Dundee, Scotland. She has recently submitted her PhD thesis supervised by Prof. Doreen Cantrell. The Cantrell lab works on T lymphocytes, which are key mediators of anti-viral and anti-tumour immune responses. Mary uses proteomics, complemented by wet lab techniques, to study how CD8 cytotoxic T lymphocytes respond to extracellular signals like cytokines and exogenous glucose to selectively control proteome stability and protein turnover. As part of this research, she has mapped the half-lives of over 6,000 proteins in cytotoxic T cells. Outside the lab, Mary enjoys music festivals and meandering around museums, and can be found at Parkrun every Saturday morning, rain or shine.

Talk Title:

"Glucose availability controls selective protein turnover in effector CD8 T cells"

Abstract for her Talk:

Glucose-sensing pathways in CD8 T cells respond to glucose depletion by modulating kinase signalling networks and protein stability to shape cell fate. High resolution mass spectrometry reveals that glucose availability controls effector CD8 T cell proteostasis, whereby withdrawal of exogenous glucose leads to a marked loss in abundance of cytokine receptors and proteins that control cell cycle progression, survival and cholesterol homeostasis; whilst driving increased abundance of the protein translation repressor PDCD4. We identify that protein synthesis is partially glucose-dependent in effector CD8 T cells, representing a key node through which glucose availability controls proteostasis. We further map protein half-lives for over 6,000 proteins, showcasing the remarkable dynamism and selectivity of protein renewal in effector CD8 T cells, which turn over more than 500 proteins every 3 hours. Notably, cytokine receptors were strongly represented amongst short half-life proteins. These data are key to understanding how any factor impacting protein synthesis will lead to loss of short half-life proteins, and indeed the ability of effector CD8 T cells to respond to cytokine signals at the site of immune activity.

A Bit About Katherine:

Katherine Fenn is a postdoctoral researcher at the University of Leeds. Her work focuses on understanding the delivery and misdelivery of OMPs to the bacterial OM. She received her PhD in Biological Sciences (2021) from Queen Mary University of London on membrane proteins involved in pathogenesis and their host-cell interactions.

Talk Title:

"BAM-BepA complexes in outer membrane protein quality control"

Abstract for her Talk:

Correct folding of outer membrane proteins (OMPs) by the β-barrel assembly machinery (BAM) is essential for maintaining the outer membrane (OM) barrier function of diderm bacteria. When OMP biogenesis is perturbed, the β-barrel assembly enhancing protease A (BepA) binds to BAM to mediate quality control, but how BepA interacts with BAM and degrades substrate OMPs remains unclear. Here, cryoEM structures of BAM-bound BepA reveals that BepA induces large conformational changes in the BAM complex enabling the enzyme to poise its active site within the periplasmic ring of BAM, beneath the BamA barrel. The lid of BepA is dynamic, embedding two of its water-soluble helices deep into the membrane bilayer when BAM-bound, which readies BepA for proteolysis of misfolding OMPs. Movement of BepA’s plug is triggered by OMP binding rather than interaction with BAM, activating the enzyme for cleavage. We reveal BepA preferentially recognises Aromatic-X-Aromatic (Ar-X-Ar) motifs which are enriched in OMP sequences. The results reveal a mechanism for proteolytic degradation by BepA in OMP quality control which requires interaction with BAM, the membrane, and its OMP substrates.