SUPT3H-less SAGA coactivator can assemble and function without significantly perturbing RNA polymerase II transcription in mammalian cells

ABSTRACT: Co-activator complexes regulate chromatin accessibility and transcription. SAGA (Spt-Ada-Gcn5 Acetyltransferase) is an evolutionary conserved multisubunit co-activator complex with modular organization. The core module of SAGA constitutes the structural heart, composed of a histone octamer like structure and two additional proteins. The central histone octamer like core structure consists of six histone fold domain (HFD)-containing proteins, forming three HF pairs (TADA1/TAF12, TAF6L/TAF9/9b, and TAF10/SUPT7L) in the mammalian SAGA complexes, to which adds SUPT3H, which contains an intramolecular HF pair. The yeast homologue of SUPT3H, called Spt3, was shown to interact genetically and biochemically with the TATA binding protein (TBP). Here we investigated the role of SUPT3H in human U2OS and mouse embryonic stem (ES) cells. Using immuno-purification coupled mass spectrometry experiments we show that both human and mouse SAGA can assemble without the double HFD-containing SUPT3H. Nascent RNA-seq experiments indicted that in either U2OS or mouse ESCs lacking SUPT3H only a small subset of genes is deregulated. Consequently, in mouse ESCs SUPT3H is not essential for mouse ESC survival, but is required for ESC growth and self-renewal. In addition, TBP recruitment experiments show no major change in TBP accumulation at gene promoters in the absence of SUPT3H in mouse and human cells. Taken together our data suggest in mammalian cells SUPT3H is not required for the assembly of SAGA, general TBP recruitment to genes and cell survival, but it is important for regulating a limited set of genes.

INSTRUMENT(S): LTQ Orbitrap Elite

ORGANISM(S): Homo Sapiens (human) Mus Musculus (mouse)

TISSUE(S): Permanent Cell Line Cell

SUBMITTER: Luc Negroni  

LAB HEAD: László Tora

PROVIDER: PXD026991 | Pride | 2022-07-26

REPOSITORIES: Pride