Exe-RIKEN: exploring the putative roles of a new TFEB and exercise related gene.

Sedentary life/work-style regimes are a western-society habit never experienced before by our species, usually resulting in metabolic maladaptation and chronic disease onset. However, on the other hand, exercise represents an effective weapon to counteract this unhealthy scenario. Consequently, there is great interest in understanding exercise beneficial effects from a molecular point of view. An uncharacterized gene, related to TFEB activity and exercise, was recently identified in Sandri's lab and renamed Exe-Riken. Exe-Riken was experimentally validated as a protein-coding gene. Moreover, the presence of both NLS and NES sequences could explain its exercise-related nucleus- to-cytosol shuttling behavior. Curiously, hind limb muscles present different gene expression levels at rest and transcriptional induction during the exercise recovery phase. This thesis describes the experimental strategies adopted to investigate this novel gene role further. In particular, NES and NLS mutated proteins were generated to clarify Exe-Riken localization upon different stimuli. Furthermore, gene expression analysis on hind limb muscles after a single bout of exercise show that after 24h, Exe-Riken reaches the transcriptional baseline only in some of the analyzed muscles, highlighting transcriptional regulation differences based on muscle fiber metabolism. Finally, the generation of a full-body Exe-Riken KO mouse and the first results regarding its characterization are here described, starting to dissect the possible role of this novel but compelling molecule.