Mapping cell structure by fusing protein images and interactions

Reviewed by Emily Henderson, B.Sc.Nov 25 2021

If cells were "countries", the proteins would be their citizens organized into inter-connected towns and villages. Thousands of proteins would populate each of these towns and villages and perform tasks essential to their functioning. Knowing the roles of each protein in the cell is essential for major advances in the fight against certain diseases such as cancer.

To date, two important experimental approaches have co-existed:

- intracellular localization: like countries, cells are composed of distinct "geographical areas" with specific characteristics. Determining the area in which a protein is found allows us to guess its function, up to a certain point.

- interactomics is the study of the interactions of a protein with other proteins in a cell. Identifying the "friends" of a protein also enables us to guess its role.

"1 + 1 = 3"

By combining these two sources of information, Denis Lafontaine's team, RNA Molecular Biology, Faculty of Science, has contributed to the discovery of a third layer of information, i.e. the detection of new protein communities and the prediction of their functions. Today, their research has been published in Nature.

Our objective was to systematically establish the different levels of organization of the cell: towns, villages, hamlets, localities, etc. and their modes of interaction."

Denis Lafontaine, RNA Molecular Biology, Faculty of Science

"We were able to show that certain proteins were close or not close. This allowed us to predict and then verify their functions within the cell," explains Denis Lafontaine.

Among other things, the study identified new protein communities involved in the production of ribosomes, which are nanomachines essential to the survival of the cells at the heart of Prof. Lafontaine's research for the past 20 years. When ribosomes are made in excess, we get cancers, and when not enough are produced, ribosomopathies, which are developmental diseases mainly affecting the blood and brain.