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HOXA5 in action: mapping DNA binding sites and uncovering protein partners in neural cell models by Amandine Vandenberghe -
Vendredi 25 septembre 2026 à 16h30 - Salle Jean-Baptiste Carnoy (B.059) - Bâtiment Carnoy - Croix du Sud - 1348 Louvain-la-Neuve -
HOXA5 has been implicated in successive stages of central nervous system development, yet the molecular mechanisms underlying its cell-context-specific functions remain poorly understood. In particular, how HOXA5 regulates transcription at distinct stages of neuronal differentiation through changes in chromatin occupancy and interactions with regulatory partners remains to be elucidated. To address this question, we combined molecular approaches to identify HOXA5 genomic binding sites, characterize its chromatin occupancy, and define functional interacting partners in neural progenitors and in cell culture differentiated into mature neurons. Our results demonstrate that HOXA5 occupies both shared and stage-enriched genomic regions and preferentially binds the canonical HOX motif. During neuronal differentiation, HOXA5 occupancy is enriched at distal regulatory and intergenic regions, although promoter-associated binding is also observed. By integrating genomic and proteomic analyses, we identified SOX2 as a chromatin-associated partner of HOXA5 and confirmed this interaction in vitro. We further demonstrated that SOX2 negatively regulates HOXA5 transcriptional activity. Our findings support a model in which HOXA5, with SOX2, may engage in a stage-specific chromatin regulatory interaction during neuronal differentiation. Using complementary approaches, we also identified SMAD1 and TSHZ3 as candidate HOXA5 interacting partners. Overall, this work provides perspectives for the identification and the characterization of HOXA5 target genes and protein partners during neuronal differentiation.
Jury members :
Prof. Françoise Gofflot (UCLouvain) (Supervisor)
Prof. René Rezsohazy (UCLouvain) (Co-supervisor)
Prof. François Chaumont (UCLouvain) (Chairperson)
Prof. Charles Hachez (UCLouvain) (Secretary)
Prof. Frédéric Clotman (UCLouvain)
Dr. Yacine Graba (Aix-Marseille Université, France)
Prof. Lucie Jeannotte (ULaval, Canada)
Pay attention : the public defense of Amandine Vandenberghe will also take place in the form of a videoconference
