Post-transcriptional regulation of sress-induced sexual differentiation by a ribonuclease

Résumé

The switch between proliferation and sexual differentiation in fission yeast is tightly regulated by multiple regulatory pathways. This regulation relies on the perception of the environment, including the presence of pheromone of the opposite mating-type, stress or nutritional starvation. Among the negative regulators of sexual differentiation in Schizosaccharomyces pombe, the endoribonuclease Pac1 has previously been identified. Pac1 selectively targets RNAs possessing a stem-loop structure, promoting either their maturation or their degradation by exonucleases. Despite a well-established understanding of its molecular function, how Pac1 is regulated in the context of sexual differentiation is currently unknown. This Master thesis aims to delve deeper into characterizing the role of Pac1, building upon prior laboratory findings indicating a rapid decrease in Pac1 abundance during nitrogen starvation. Firstly, through Western blot analyses, we were able to highlight Tor2, the catalytic subunit of the TORC1 complex, as one of the players governing Pac1 regulation. Further perturbation of the TORC1 pathway in condition of nitrogen starvation suggested a double regulation exerted on Pac1 during nitrogen stress. We also investigated the phosphorylation of two Pac1 residues, as a post-translational marker potentially involved in the stabilization of the protein. However, to date, we have not been unable to highlight a positive or negative role of those phosphorylation mark in Pac1 stability.

la date de réponse	15 janv. 2024
langue originale	Anglais
L'institution diplômante	Universite de Namur
Superviseur	Carlo Yague-Sanz (Promoteur)