Embryonic development relies on highly complex and dynamic molecular interactions, some of which relate to protein-protein interactions (PPIs). The importance of PPIs is well established in all fundamental cellular processes including transcriptional regulation or post-translational modifications. Thus, deciphering protein interaction networks is crucial for the understandingof molecular rules underlying embryonic developmental programs.
This feature is at the base of the projects of the team, by using a conserved family of transcription factors, the Hox proteins, as a case study. Indeed, although the role of Hox proteins is well established in several developmental and pathological processes, their molecular modes of action remain poorly understood. The weak number of Hox transcriptional partners identified so far in part explains this lack of knowledge.
Projects of the team aim to tackle this question, in particular by using the BiFC (Bimolecular Fluorescence Complementation) visualization method. We recently described the experimental parameters for using BiFC in living Drosophila or chicken embryos. Importantly, this method allows analysing protein-protein interactions in an otherwise wild type cellular environment and with protein expression levels closed to the endogenous ones. BiFC thus allows asking for new potential regulatory modes that could be tightly linked to the cell context. Finally, the discovery of new protein interaction networks will be coupled to the search for target genomic regulatory sequences. Integrating these two levels of analysis, protein-protein and protein-DNA interactions should relieve some of the mysterious molecular rules that characterize Hox transcriptional specificity in vivo.
