Project description:In this project, we made a comprehensive quantitative proteomic analysis of four defined developmental stages of S. parasitica (mycelium, primary cysts, secondary cysts and germinated cysts) to gain greater insight into the types of proteins specifically linked to each stage. A total of 2423 unique proteins were identified using qualitative (gel-based) and quantitative (iTRAQ, isobaric tags for relative and absolute quantitation) approaches. Of these, 358 proteins, associated with various biological processes, were found to be significantly enriched between different life cycle stages of S. parasitica. The transcript abundance of several cyst and mycelium enriched proteins was also checked by quantitative real-time PCR. This is the first large scale proteomic analysis on Saprolegnia and the data from this study will enhance our current knowledge about this pathogen by identifying biological processes key to each developmental stage.
Project description:Oomycete cells are surrounded by a polysaccharide rich cell wall matrix that, in addition to being essential for cell growth, also functions as protective ”armour”. It follows, that the enzymes responsible for the synthesis of the cell wall provide potential targets for disease management. Interestingly, the oomycete cell wall enzymes are predicted to be plasma membrane proteins. In this project, we used a quantitative (iTRAQ) mass spectrometry-based proteomics approach to characterize the plasma membrane proteome of the hyphal cells of S. parasitica, providing the first complete plasma membrane proteome of an oomycete species. Of significance, is the identification of proteins enriched in functional microdomains (Detergent-Resistant Microdomains; DRMs). In silico analysis showed that DRM-enriched proteins are mainly involved in both molecular transport and β-1,3-glucan synthesis, potentially contributing to post infection pathogenesis.
