The Top 10 Discoveries of the Year according to Québec Science
80,000 New Anonymous Proteins
Sherbrooke, le 6 janvier 2014 – Sherbrooke, January 6, 2014 – The investigations of a team in the Faculty of Medicine and Health Sciences of the Université de Sherbrooke and the CHUS's Centre de Recherche Clinique Étienne-Le Bel rank among the top 10 discoveries in 2013 published in the January edition of Québec Science. The discovery of more than 80,000 proteins – referred to as alternative proteins – is shaking up medicine and biology by putting into question knowledge about proteins.
In August 2013, the team of Xavier Roucou, professor in the Department of Biochemistry, published the discovery of these proteins – until then unknown – in PLoS ONE. Two examples of alternative proteins identified in the laboratory had previously been published in FASEB Journal and Journal of Biological Chemistry. The identification of these proteins opens a new doorway to understanding certain neurodegenerative diseases.
Tenet of One Protein per messenger RNA Undone
DNA contains all of the information essential to the proper operation of the body's cells. Genetic material is safely packed in the nuclei of our cells. This material is required to produce proteins (molecules) to accomplish most cell functions. Consequently, genes must first be transcribed into messenger RNA (mRNA), which is then processed into mature mRNA. Mature mRNA is decoded by "mobile plants" called ribosomes, which are translated into proteins. In short, the ribosome decodes mature mRNA and manufactures the protein corresponding to the origin gene.
mRNA No Longer translated into one Protein only
Cells use mRNA as an intermediate support in producing the proteins they need. One tenet still persists about this mechanism: ribosomes produce a single protein for each mature mRNA, referred to as the reference protein, which plays a very specific role in the cell. Professor Roucou's team discovered that there is not just one way to decode a mature mRNA.
"We can now affirm that the tenet is inexact," explained Roucou. Ribosomes can decode the information transmitted to them by mRNA in a variety of ways, leading to the production of many completely different alternative proteins." In short, from a single mature mRNA, cells produce not one, but many distinct proteins, which necessarily involves many functions.
A Perplexing Discovery for the Scientific Community
The community is perplexed since the discovery puts into question what has long been considered basic knowledge in biology. The observation is so disturbing that Roucou's team had a hard time getting its work published in the most prestigious journals. "Our findings are provocative," explained Roucou. "We have realized that in analyzing the comments made by reviewers and editors. We had to provide more demonstrations to support our findings."
About the Research Team
Xavier Roucou is a professor in the Faculty of Medicine and Health Sciences and investigator at the Centre de Recherche Clinique Étienne-Le Bel at the Centre hospitalier universitaire de Sherbrooke. The members of his laboratory who worked on the discovery of alternative proteins are students Benoît Vanderperre, Danny Bergeron, Cyntia Bissonnette, Catherine Lapointe, and Solène Vanderperre and research professionals Guillaume Tremblay and Julie Motard.
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Isabelle Huard, Media-Relations Officer
Communications Department | Université de Sherbrooke
819 821-8000, extension 63395 | Isabelle.Huard@USherbrooke.ca