An Integrated Understanding of the NuA4 Coactivator Complex (360G-Wellcome-102535_Z_13_A)

Coactivators SAGA and NuA4 stimulate transcription by post-translational modifications of chromatin, but also have important roles in DNA repair and mRNA export. Both contain Tra1, a highly conserved 3744-residue protein that belongs to the Phosphoinositide 3-Kinase-related kinase (PIKK) family. Tra1 enables targeting of SAGA/NuA4 to specific genes, by directly interacting with DNA-bound activator proteins, but the molecular details are unknown. Understanding how Tra1 functions within these complexes is critical for elucidating how they cooperate and function in multiple processes. By combining structural, functional and systems biology techniques, we will focus on the Tra1 protein and the NuA4 complex to produce an integrated understanding of their functions. We have two key goals: (1) determining the molecular mechanisms behind activator targeting of Tra1 and their importance for SAGA and NuA4 recruitment during gene activation and (2) solving a complete and high-resolution structure of the NuA4 coactivator complex that will provide an integrated understanding of its functions in transcription and DNA repair. We also have preliminary data in new projects that will expand our research programme beyond the fellowship, by exploring the mechanisms of Tra1 in DNA repair, the relationships between different PIKKs, and the structure and function of histone methyltransferase complexes.