TATA-Box Binding Protein O-GlcNAcylation at T114 Regulates Formation of the B-TFIID Complex and Is Critical for Metabolic Gene Regulation
MOLECULAR CELL
Authors: Hardiville, Stephan; Banerjee, Partha S.; Alpergin, Ebru S. Selen; Smith, Danielle M.; Han, Guanghui; Ma, Junfeng; Talbot, C. Conover, Jr.; Hu, Ping; Wolfgang, Michael J.; Hart, Gerald W.
Abstract
In eukaryotes, gene expression is performed by three RNA polymerases that are targeted to promoters by molecular complexes. A unique common factor, the TATA-box binding protein (TBP), is thought to serve as a platform to assemble pre-initiation complexes competent for transcription. Here, we describe a novel molecular mechanism of nutrient regulation of gene transcription by dynamic O-GlcNAcylation of TBP. We show that O-GlcNAcylation at T114 of TBP blocks its interaction with BTAF1, hence the formation of the B-TFIID complex, and its dynamic cycling on and off of DNA. Transcriptomic and metabolomic analyses of TBPT(114)A CRISPR/Cas9-edited cells showed that loss of O-GlcNAcylation at T114 increases TBP binding to BTAF1 and directly impacts expression of 408 genes. Lack of O-GlcNAcylation at T114 is associated with a striking reprogramming of cellular metabolism induced by a profound modification of the transcriptome, leading to gross alterations in lipid storage.
Helicase89B is a Mot1p/BTAF1 homologue that mediates an antimicrobial response in Drosophila
EMBO REPORTS
Authors: Yagi, Y; Ip, YT
Abstract
We have identified a novel component, Helicase89B, that is required for the inducible antimicrobial response in Drosophila larvae by means of a P-element insertional genetic screen. Helicase89B belongs to the Mot1p/BTAF1 subfamily of SNF2-like ATPases. This subfamily can interact with TATA-binding proteins, but whether the interaction leads to gene activation or repression is being debated. We found that Helicase89B is required for the inducible expression of antimicrobial peptide genes but not for the inducible expression of heat-shock genes. The antimicrobial peptide genes are activated by the Toll and immune deficiency (IMD) signalling pathways. Genetic experiments show that Helicase89B acts downstream of DIF and Relish, the two nuclear factor-kappa B (NF-kappa B)-related transcription factors that mediate Toll- and IMD-stimulated antimicrobial response. Thus, Helicase89B positively regulates gene expression during innate immune response and may act as a link between NF-kappa B-related transcription factors and the basal transcription machinery.