Genome-wide ChIP-exo profiling of Fpt1 in glucose

Transcription of transfer-RNA genes (tDNAs) by RNA Polymerase III (RNAPIII) is tightly regulated upon nutrient and stress signaling. However, identical tDNAs across the genome are differentially regulated, suggesting regulation at the chromatin-level plays a crucial role. This study aimed to identify such mechanisms by decoding the chromatin proteome of a native tDNA locus in yeast using Epi-Decoder. The tDNA proteome showed dynamic binding of both known and unknown factors upon nutrient stress, including Ykr011c (Fpt1), a protein of unknown function. Decoding the tDNA proteome in the absence of Fpt1 revealed a role in the eviction of RNAPIII during repressed transcription. Fpt1 exclusively occupied RNAPIII-regulated genes, but cells without Fpt1 also showed impaired shutdown of RNAPII-transcribed ribosome biogenesis genes in changing nutrient conditions. These findings provide support for a novel chromatin-associated regulator required for proper RNAPIII assembly that also tunes an integrated physiological response to changing metabolic conditions. Overall design: Genome-wide ChIP-exo binding profiles of Fpt1 were determined using high throughput paired-end sequencing using ChIP-exo 5.0.