Research projects

Chemical biology of membrane proteins

The study of small transmembrane proteins can often be challenging. In particular, it can be difficult to tag these proteins with a fluorophore in cellulo without perturbing the proteins localization and function, or to extract and purify them from membranes, without disturbing their structure or interactions with other proteins, for structure determination or for mass spectrometry interaction proteomics. Additionally, these proteins can be post-translationally modified by lipids, but proteomics methods to precisely identify and quantify some of these modifications are noticeably lacking.

We aim to develop and/or apply a combination of chemical and biological approaches to facilitate the study of these small membrane proteins.

Characterization of S-palmitoylated membrane proteins involved in viral infection

The first aim of our work is to use a combination of chemical approaches (site-specific chemical labelling, crosslinking interaction proteomics, chemical proteomics, genetic code expansion, solid state NMR) to characterize small transmembrane proteins involved in viral infections. Some of these proteins are post-translationally modified by S-palmitoylation, which corresponds to the reversible addition of a C16 fatty acid to Cys, often adjacent to the protein transmembrane domain. S-palmitoylation is essential for protein localization and regulation, but its precise function, notably during viral infection, remains unknown for some proteins.

Using a combination of methods, we are currently characterising a small protein involved in viral infections by studying the role and regulation of its S-palmitoylation, its structure in interaction with membranes and by identifying its interaction partners. These studies will help us to understand if this protein could be new antiviral drug target.

New tools for endogeneous protein tagging

The second aim of our work is to develop new methods to tag proteins at the endogenous level (no overexpression). The addition of a tag to a protein, such as GFP (Green Fluorescence Protein) for immunofluorescence studies, can sometimes perturb the protein biophysical properties, localization and/or function. The tag is often added by overexpressing the protein of interest, which can sometimes lead to toxicity, hence the development of new methods to tag proteins at the endogenous level is essential. The tag could be a small fluorophore (BODIPY, etc) for live cell imaging studies or a crosslinking moiety to enable the identification of the interactome of the protein of interest by mass spectrometry-based proteomics. These new methods will be applied to facilitate the study of small membrane proteins.

Funding