An ENU-induced point mutation in the mouse Btaf1 gene causes post-gastrulation embryonic lethality and protein instability
MECHANISMS OF DEVELOPMENT
Authors: Wansleeben, Carolien; van Gurp, Leon; de Graaf, Petra; Mousson, Florence; Timmers, H. Th. Marc; Meijlink, Frits
Abstract
The mouse Btaf1 gene, an ortholog of yeast MOT1, encodes a highly conserved general transcription factor. The function of this SNF2-like ATPase has been studied mainly in yeast and human cells, which has revealed that it binds directly to TBP, forming the B-TFIID complex. This complex binds to core promoters of RNA polymerase II-transcribed genes and, of crucial importance, BTAF1-TBP interactions have been shown to affect the kinetics of TBP-promoter interactions. Here we report the isolation of a mouse line carrying a Btaf1 allele containing an ENU-induced point mutation that causes a substitution mutation in the BTAF1 ATPase domain. Embryos homozygous for this loss-of-function mutation appear to be morphologically normal until early somite stages, but die between embryonic days 9 and 10.5 displaying growth arrest and edema. Analyses in vitro suggest that the altered protein is less stable and, independent from this, functionally impaired in releasing of TBP from chromatin, but not in binding to TBP. (C) 2011 Elsevier Ireland Ltd. All rights reserved.
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.
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