Differential requirements for Gcn5 and NuA4 HAT activities in the starvation-induced versus basal transcriptomes

ABSTRACT: The histone acetyltransferase (HAT) subunit of coactivator complex SAGA, Gcn5, is required for efficient eviction of promoter nucleosomes at certain highly expressed yeast genes, including those activated by transcription factor Gcn4 in amino acid-deprived cells; however, the importance of other HAT complexes in this process was poorly understood. Analyzing mutations that disrupt the integrity or activity of HAT complexes NuA4 or NuA3, or the HAT Rtt109, revealed that only NuA4 acts on par with Gcn5, and functions additively, in evicting and repositioning promoter nucleosomes and stimulating transcription of starvation-induced genes. NuA4 is generally more important than Gcn5, however, in promoter nucleosome eviction, TBP recruitment, and transcription at most other genes expressed constitutively. NuA4 also predominates over Gcn5 in stimulating TBP recruitment and transcription of genes categorized as principally dependent on the cofactor TFIID versus SAGA, except for the highly expressed subset encoding ribosomal proteins (RPs), where Gcn5 contributes strongly to PIC assembly and transcription. Both SAGA and NuA4 are recruited to promoter regions of SM-induced genes in a manner that appears to be feedback controlled by their HAT activities. Our findings reveal an intricate interplay between these two HATs in nucleosome eviction, PIC assembly, and transcription that differs between the starvation-induced and basal transcriptomes.

ORGANISM(S): Saccharomyces cerevisiae

PROVIDER: GSE207278 | GEO | 2023/02/02

REPOSITORIES: GEO