Microprotéome:​ exploration d'un réservoir moléculaire pour l'agronomie et la santé

ABSTRACT

Microproteins are an emerging class of proteins in the literature. They result from the translation of a short reading frame on a transcript and do not meet the annotation criteria for canonical proteins. Like canonical proteins, they are described as being involved in various biological processes such as development, growth, metabolism, maintenance of genetic material, responses to biotic and abiotic stress, and the development of pathologies. The microproteome is therefore a particularly interesting molecular reservoir to explore, both from an agronomic point of view and in the field of health. However, there are currently few examples of microprotein identification and molecular characterization in the literature. This topic is therefore central to the work carried out as part of my PhD entitled “The microproteome: a molecular reservoir for agronomy and health.” The results presented are divided into three main sections, each focusing on the study of microproteins but in different biological contexts and organisms. The first part of this thesis is devoted to developing an approach for detecting microproteins and canonical proteins associated with pancreatic cancer, with the longer-term goal of identifying new targets and therapeutic avenues as well as biomarkers associated with this cancer. The results also suggest an approach that could be extended to other forms of disease in the future. The second and third parts are devoted to characterizing the molecular mode of action of a particular class of microproteins, peptides encoded by microRNAs (miPEPs), in plants and animals. In particular, my work was based on the hypothesis that this mode of action relies on peptide/protein interactions, and therefore led me to define the protein interactome of miPEP165a from the model plant Arabidopsis thaliana and miPEP8 from Drosophila melanogaster.