Hangover regulates gene expression by limiting NSL-mediated H4K16 acetylation.

The RNA-binding protein Hangover (Hang) is essential for several stress responses in Drosophila melanogaster. Here, we discover a novel function of Hang in the regulation of gene expression. Hang binds to >2000 genes in the Drosophila genome and modulates transcription. We identify a diverse set of chromatin regulators as Hang interactors, including NSL, dMec, Sin3A, dREAM, and Ino80. Among these, the non-specific lethal complex (NSL) is the most prominent one. We show that Hang attenuates NSL-mediated H4K16 acetylation at transcriptional start sites to downregulate gene expression. Our work uncovers novel roles for Hang in epigenetic gene regulation and suggests that it coordinates the function of multiple chromatin regulators.