Functional dissection of BET chromatin readers in transcription

Oklahoma Medical Research Foundation, Oklahoma City OK

Investigators

Abstract

The precise control of gene transcription is necessary for the normal development of cells. Mistakes in this process can have detrimental consequences. In eukaryotic organisms, from simple unicellular yeast to humans, DNA is stored as chromatin, which consists of a DNA strand wrapped around proteins called histones. Many proteins that regulate transcription can “read” chromatin through specific modifications on histones, and this activity helps guide their function. Proteins from the bromodomain and extra-terminal domain (BET) family are chromatin readers that regulate the transcription of most genes in eukaryotes. Despite the importance of BET proteins in transcription, the specific roles of these proteins are not fully understood. The project will address this gap in knowledge by investigating the roles of BET proteins in baker’s yeast, which is an excellent model for understanding processes in human cells. The project will have important societal impacts by providing experience in original, hypothesis-driven research for a broadly diverse group of young scientists, from different backgrounds and at different levels of education, from high school to college students. There are important gaps in understanding the major steps of gene transcription due to limited insight into the biology of BET proteins. For example, other than the bromodomains, which target BET proteins to acetylated chromatin, the functions of conserved domains of BET proteins are largely unknown. Further, recent findings indicate that there are mechanisms of BET protein recruitment that do not involve bromodomains. The overall objective of the project is to determine the contributions of all conserved domains of BET proteins to transcription in yeast. The objective will be accomplished by defining the contributions of conserved BET protein domains to mRNA synthesis, BET protein recruitment to chromatin, and formation of the transcription pre-initiation complex at gene promoters. The project will leverage powerful yeast genetic tools and modern genomic technologies to facilitate high-throughput investigation. The outcome of the project will be the first systematic characterization of the mechanisms by which BET proteins regulate transcription in a single model system. Thus, the project will expand the model of transcriptional regulation in yeast, and due to the conservation of BET proteins, it will direct future studies in diverse eukaryotes. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.