Summary of the proposal :
Comparative proteome analysis of C. albicans strains SC5314 and CAI4
Proteomics is a rapidly evolving field. Initially devoted to protein identification, it is today aiming at an in-depth characterization of proteomes to reach functional proteomics. This leads to new challenges including the analysis of post-translational modifications playing a key role in protein function, the identification of protein complexes and the study of their dynamics, the quantitative determination of proteome variations upon various stimuli or in different cellular states, and the detection of low-abundance proteins of biological importance.
Over the past decade, mass spectrometry (MS) has represented a key technology for the analysis of biomolecules in general and of proteins in particular, becoming a central analytical tool for the development of proteomics.
The recent advances in MS instrumentation with the latest mass spectrometers such as the orbitrap offer unprecedented capabilities in terms of sensitivity, acquisition speed, and mass resolution, which open exciting new areas of proteomic applications. Combined with sophisticated biochemical methods for protein extraction, separation, and purification, and dedicated bioinformatics tools for data analysis, these MS-based strategies are becoming powerful complementary approaches to cellular, pharmacological, and other molecular techniques to contribute significantly to the understanding of complex regulatory protein networks.
In this context, the research projects of the group of Dr B. Monsarrat devoted to the analysis of biological systems involved mainly in cancer and inflammation trigger the development of state-of-the-art proteomic strategies. The principal aim of the Toulouse Proteomics Platform is to provide state-of-the-art techniques in proteomics to the scientific community.
Proteomics is a rapidly expanding field, where instrumentation in mass spectrometry and associated analytical and biochemical strategies are regularly improving.
The development of quantitative proteomic strategies have been so far successful thanks to improved mass spectrometers capabilities (high resolution, high acquisition speed, high sensitivity) and to new bioinformatic tools, and should develop further in the coming years. Toulouse Proteomics Platform is equipped with modern mass spectrometers and has increased its capacities in bioinformatics over the last 4 years.
Our group in Valencia work in yeast cell wall structure, in particular we are interested in the human yeast pathogens of the genus Candida and nearest species and in particular C. Albicans. Actualy more molecular studies in this species were carried out with the mutant strain CAI4, and his parental clinical strain SC5314. However Although CAI4 has been initially described as a auxotrophic mutant, abnormal phenotypes not associated to uracil auxotrophy have been soon observed.
Differences in the proteome of these strains can explain these differences and addimportant data for validation of molecular and clinic results carried out with this strain.
Protein samples of C. albicans strain CAI4 and his parental SC5314, had been used to contrastthe proteome of these strains in different conditions of culture, including iron depletion, oxidative and nutritional stress.
Comparison of proteome of these strains by complex mixture analysis allow us to identify ≈750 validate proteins by comparison of peptides sequences with C. albicans protein data bank at Pasteur institute. Comparison of proteins of cells grown in standard conditions, allows us to show important differences between both strains proteome, in particular a under expression of ribosomal proteins in The CAI4 strains.
Analysis of strips after SDS-PAGE separation and comparison of proteome in different stress conditions are still under bioinformatics analysis.
The contacts realised in Toulouse open the door for further collaborative projects with the diferents groups at the “Institut de Pharmacologie et de Biologie Structurale”