The biggest ever interactome network showing the possible protein-protein interactions of a cell, has been mapped for the model organism Arabidopsis thaliana, a plant from the mustard family. The results of this study, published in Science, show in particular that natural selection would act directly on the protein-protein interaction network.  

Birth of a passion...

A chemical bioengineer and today a researcher at the Unit of Animal Genomics of GIGA at the Université de Liège, supervised by Professor Michel Georges, Benoît Charloteaux is particularly interested in studying the structure and function of proteins as well as interactions between these macromolecules that are essential for life. During his thesis in molecular modelling in the laboratory of Professor Robert Brasseur at Gembloux Agro-Bio Tech, he studied the interactions between proteins and biological membranes, with a particular focus on the protein GP41 of the Human Immunodeficiency Virus. This so-called ‘fusion’ protein is located within the viral envelope and allows him to enter the target cell in order to take control of it. Although this research had, until then satisfied his interest in proteins, in 2006 Benoît Charloteaux discovered he had a real passion for systems biology. "Professor Marc Vidal, alumni from Gembloux who now runs the Center for Cancer Systems Biology at the Dana-Farber Cancer Institute (Boston), held the Francqui Chair and I attended several of his lectures on systems biology", recalls Benoît Charloteaux.

Systems biology is a growing field that aims at studying all interactions between the components of a biological system. These interactions can involve macromolecules such as DNA, proteins etc. "As an analogy, systems biology is like watching all the parts of an engine. It is, of course, interesting to know each part separately but how they are connected and work together also needs to be understood", says Benoît Charloteaux. As with an engine, where the way in which the parts are assembled explains whether it works well or not, the network of interactions between the various elements of a cell make it possible to understand why a cell or organism works or not. Thus, to better understand the relationship between genotype and phenotype, the underlying interactome should be analysed, that is the way in which all macromolecules interact within a cell.

… and collaboration

Following his meeting with Marc Vidal and the birth of his new passion, systems biology, Benoît Charloteaux decided to contact the scientist to suggest working together (1&2). "His laboratory is specialised in the mapping and study of interactome networks and we had expertise in terms of analysing the structure of proteins, central components of these interactomes" says the researcher. The two laboratories then worked together on two projects tackling perturbations of protein networks and their impact on the phenotype. "The aim was to understand how perturbations of specific interactions within the interactome could alter the phenotype", specifies Benoît Charloteaux. 

(1) Zhong Quan,  Simonis Nicolas, Li, Qian-Ru, Charloteaux Benoît, Heuze Fabien, Klitgord Niels, Tam Stanley, Yu Haiyuan, Venkatesan Kavitha, Mou Danny, Swearingen Venus, Yildirim Muhammed A., Yan Han, Dricot Amelie, Szeto David, Lin Chenwei, Hao Tong, Fan Changyu, Milstein Stuart, Dupuy Denis, Brasseur Robert, Hill David E, Cusick Michael E, Vidal Marc, Systems biology is a growing field that aims at studying all interactions between the components of a biological system., Molecular Systems Biology, 2009. (http://orbi.ulg.ac.be/handle/2268/63253)
(2) Dreze Matija, Charloteaux Benoît, Milstein Stuart, Vidalain Pierre-Olivier, Yildirim Muhammed A, Zhong Quan, Svrzikapa NenadRomero Viviana, Laloux Geraldine Brasseur Robert, Vandenhaute Jean, Boxem Mike, Cusick Michael E, Hill David E, Vidal Mar, 'Edgetic' perturbation of a C. elegans BCL2 ortholog., Nzature Methods, 2009. (http://orbi.ulg.ac.be/handle/2268/63262)