Proteomics based on high-resolution mass spectrometry is a powerful tool for profiling expressed proteins within cells, organs or tissues. It provides comprehensive information on the dynamics of cellular processes, modifications, and interactions. My research focuses on “bottom-up” proteomic, which is often used synonymously with shotgun proteomics, based on the global identification and quantification of enzymatically-digested proteins. It is the method of choice for discovery-driven proteomics, as it is unbiased, robust, and sensitive.

     Here, I will discuss recent findings and novel technological applications in the field of proteomics. I will highlight and communicate proteomics-associated research in a relatable and straight-forward manner, as well as include interviews with the authors and principle investigators. Ultimately, I will establish a website that contributes to the effective communication of proteomic science and provides an opportunity to introduce its power and diversity in the classroom.

A bit about me

     I first began using proteomics during my Master’s degree at the University of Lethbridge in 2006, to investigate the impact of Fusarium gramineraum infection on barley. At the time, mass spectrometry-based proteomics was a relatively new field and its use to profile the functional relevance of infection was fascinating to me. I relied on 2D-SDS-PAGE (two dimensional-sodium dodecyl sulphate-polyacrylamide gel electrophoresis) to separate the proteins and a service lab to process the samples. I spent hours staring at black spots on a computer screen and would even see the proteins when I closed my eyes. This was the beginning of something great!

    I continued to study fungal pathogenesis using proteomics during my PhD at the University of British Columbia in the lab of Dr. Jim Kronstad. Working with Cryptococcus neoformans presented many new challenges, but the advancement in MS technology and diverse applications allowed me to comprehensively investigate the secretome and cellular proteome of the fungal pathogen under different regulatory conditions. The results were very exciting and lead to the proposal of a drug-repurposing strategy to treat cryptococcal infections.

     Today,  I am a Humboldt and NSERC post-doctoral research fellow in the lab of Prof. Dr. Matthias Mann at the Max Planck Institute of Biochemistry. I am using state-of-the-art quantitative proteomics to characterize host-pathogen interactions. Specifically, to elucidate the mechanisms by which pathogenic microbes interact with the host and manipulate the immune system.

Suggested reading:

Geddes, J.M.H., Caza, M., Croll, D., Stoynov, N., Foster, L.J., Kronstad, J.W. (2016) The ubiquitin-proteasome pathway in Cryptococcus neoformans influences capsule production, is regulated by protein kinase A, and is an antifungal target. MBio. 7(1):e01862-15.

Geddes, J.M.H., Croll, D., Caza, M., Stoynov, N., Foster, L.J., Kronstad, J.W. (2015) Secretome profiling of Cryptococcus neoformans reveals regulation of a subset of virulence-associated proteins and potential biomarkers by Protein Kinase A. BMC Microbiol. 15:206. DOI 10.1186/s12866-015-0532-3.

Geddes, J.M.H., Eudes, F., Laroche, A., Selinger, L. B. (2008) Differential expression of proteins in response to the interaction between the pathogen Fusarium graminearum and its host, Hordeum vulgare. Proteomics. 8:545-54.