SAGA Transcription Coactivator Complex Is Associated with Histone Locus Body HLB

The chromatin of histone genes is associated with specific nuclear biomolecular condensate called the histone locus body (HLB). HLB is the compartment where the transcription of histone genes and processing of their pre-mRNAs coordinated with the cell cycle take place. In this work, the transcriptional histone acetyltransferase coactivator complex SAGA is described as a component of the HLB. Specific subunits of the SAGA complex, Gcn5 and Sgf11 proteins, are present on the chromatin locus of the histone gene cluster and interact with known constant specific structural components of the HLB (Mxc, FLASH, and Mute proteins).