Gene Regulation and Control of Chromatin Structure by Abf1 and Rap1

Health Research Incorporated/New York State Department Of Health, Menands NY

Investigators

Abstract

Rap1 and Abf1 are General Regulatory Factors (GRFs) that function in transcriptional activation and repression, replication, and telomere structure in yeast. These two GRFs share an ability to create a local region of open chromatin which can facilitate binding of other activators to gene promoters and thus contribute to gene activation. However, these two GRFs also differ in some respects. Most dramatically, continued binding of Rap1 is required to facilitate ongoing transcriptional activation, whereas loss of Abf1 binding (using an abf1-1 ts mutant) does not result in decreased transcription. Thus, at least some promoters retain a "memory" of Abf1 binding. In this project, new insight into the mechanism by which Rap1 and Abf1 contribute to transcriptional activation and perturb local chromatin structure, and into the basis of this "memory effect," will be obtained using a combination of biochemical, genetic, and genomic approaches. Gene activation depends on binding of specific transcription factors to gene promoters. In this project, two such factors, Abf1 and Rap1, that operate as "General Regulatory Factors" by assisting in activation of many genes in yeast will be investigated. The studies will include biochemical, genetic and genomic approaches to understanding the mechanism by which these two factors contribute to transcriptional activation, including their effects on the packaging of gene promoters into chromatin. The results of this work will provide new information that is likely to apply to all eukaryotes, as the transcription machinery is highly conserved. These investigations will include participation by undergraduates conducting summer research, and will yield genomic data that will be made available to the scientific community.