Staufen1 est un régulateur post-transcriptionnel du cycle cellulaire
The cell cycle is crucial for growth, but also for development. This mechanism is so critical that the slightest damage to one of its stages can lead to problems of growth and development, but also to the appearance of anomalies, such as cancers, and ultimately death. As a result, cell proliferation is a finely regulated mechanism, best avoiding possible failures and imbalances.  The regulation mechanisms of the cell cycle transitions are grouped at several levels, and are highly hierarchical and structured: the transcriptional and post-translational regulations are among the most studied aspects to date. Other processes, such as post-transcriptional regulation, are less documented. However, number of discoveries of RNA-binding proteins, which play a key role in the different phases of the division cycle, is increasing since the past decade. Splicing, nuclear export, localization, degradation and translation of mRNAs represent the multiple aspects of post-transcriptional regulation, and amply justify their importance in refining the control of the different phases of the cell cycle.  Staufen1, an RNA-binding protein, is one of the incredible discoveries that have revolutionized our understanding of gene expression regulation, and has helped deepen our understanding of the mechanisms underlying various cellular and physiological processes. The research work undertaken during this thesis has contributed to deepening our knowledge of Staufen1 protein function in the post-transcriptional regulation of the cell cycle and proliferation. We have identified a new mechanism of degradation of STAU1 during mitosis exist, involving the ubiquitin-proteasome system. We have also shown for the first time that STAU1 could inhibit tumor proliferation in colorectal cancer, and our results have been confirmed and extended in later studies. Moreover, the results of our experimental approaches in untransformed cellular models, strongly suggest a positive roleof Staufen1 in promoting the proliferative potential during tumorigenesis. . These results are consistent with a multitude of studies showing the positive role of STAU1 in the regulation of proliferation and its involvement in various types of cancers. However, more comprehensive review of Staufen1 studies suggests a multi-mechanistic model in the various carcinogenic processes, and opens up a future field of investigation to elucidate the molecular mechanisms that support the STAU1 functions associated with cell proliferation and tumor development.
Staufen Cell cycle Proliferation Post-transcriptional regulation