TFIIIC dinamically binds Alu elements to control gene expression through chromatin looping

Folding of the mammalian genome is governed by architectural proteins, such asCTCF. TFIIIC, a RNA polymerase III transcription factor, has been identified as aninsulator but its role in genome topology is totally unknown. Here, we show that TFIIICestablishes long-range genomic interactions that affect gene expression. Upon serumstarvation (SS), TFIIIC occupancy increases at Alu elements (AEs) near promoters ofcell cycle-related genes. Bound AEs become H3K18 hyper-acetylated and fold tocontact distal pre-loaded CTCF sites near other cell cycle genes. The promoters ofthese genes also become hyper-acetylated ensuring their basal transcription during SSand their increased expression during serum re-exposure. Ablation of TFIIIC ordeletion of the TFIIIC-bound AE that loops to the G2/M cycling F (CCNF) locus affectsits expression and nuclear positioning. These results illustrate a novel function ofhuman TFIIIC in changing 3D genome topology through the epigenetic state of AEs.