MOF is a histone acetyltransferase that plays a central role in dosage compensation and in the regulation of housekeeping genes. It is conserved from Drosophila to mammals and associated with two distinct complexes, MSL and NSL complexes, which determine its substrate specificity. Accumulating evidence points towards a pathological significance of human MSL and KANSL complexes, especially in disorders associated with intellectual disability. Yet, the regulatory mechanisms these complexes govern in transcription regulation have remained largely unexplored. My PhD project anticipates gaining novel insights into the role of mammalian MSL and KANSL complexes in transcription dynamics.