Project description:The SAGA coactivator complex facilitates transcription initiation through chromatin-modifying activities and interaction with TBP. SAGA was suggested to regulate the expression of about 10% of yeast genes, leading to the longstanding distinction of SAGA-dominated from TFIID-dominated genes, depending on the complex used to recruit TBP to promoters. We reassessed the genome-wide localization of SAGA by using ChEC-seq and its role on transcription through quantification of newly-synthesized mRNA. Here we show that SAGA binds to the upstream activating sequences of a majority of yeast genes. Deletion analyses reveal a global role for SAGA in transcription and a synergistic effect of Spt3 (TBP-binding subunit) with the acetyltransferase Gcn5. Our data demonstrate that SAGA acts as a general cofactor required for essentially all RNA polymerase II transcription. Hence, differential gene regulation, largely attributed to either SAGA or TFIID dominancy, is not accurate, but instead depends on other features of genes promoters.
Project description:The SAGA coactivator complex acts on the whole transcribed genome and is required for RNA polymerase II transcription [Yeast cells]
Project description:Transcription initiation in eukaryotes by RNA polymerase II requires numerous general and regulatory factors including the general transcription factors. Here, we report a new cofactor of the general transcription factor IIF, GAS41, which was previously implicated in tumor development. Microarray analysis of cells with induced overexpression of cofactor GAS41 identifies a significant number of up-regulated transcripts (p-value of 0.01). Keywords: altered gene expression
