ABSTRACT
Proper regulation of gene expression is essential in ensuring an organism's function, fitness and thus survival.
Cells possess many regulatory mechanisms for the control of gene expression. Variation at any level of this
regulation can contribute to variation in gene expression that can ultimately result in differences in morphology,
physiology and behavior that are the root cause of many human diseases including heart disease,
neurodegenerative disease and cancer. This proposal is focused on the regulation of transcription, the first step
in gene expression and arguably the most tractable experimental system. The rate of transcription is determined
by the interaction of transcription factor (TF) proteins that bind to regulatory DNA sequences of each gene and
act as activators or repressors to modulate gene expression level. Each gene is tightly controlled by networks of
regulatory interactions that contain all the genes in the genome and are inherently complex and difficult to
enumerate and quantify. Additionally, the structure, connections and regulatory relationships of genes are highly
context dependent, capable of dramatic change in response to intrinsic or extrinsic environmental cues. One of
the best-studied regulatory networks is that of the baker's yeast Saccharomyces cerevisiae, yet despite
numerous studies designed to identify the TF-target gene connections in this network, very little is known about
the quantitative relationship between TF expression level and the resultant changes in the expression levels of
target genes. This relationship, termed the gene regulation function (GRF), has only been quantified in detail in
a small number of studies that focused on individual pairs of TF and how they regulate a single target gene.
Because we have so few examples of the GRF, fundamental questions remain about this relationship and almost
nothing is known about how the GRF changes in response to environmental differences. This proposal will fill
this knowledge gap by titrating the expression level of a well-studied TF (RAP1) that has diverse roles in the the
cell and regulates hundreds of genes, to determine how the location of DNA binding changes and therefore the
specific regulatory connections it makes in response to altered TF abundance and the ultimate effect TF
abundance has on target gene expression levels. By determining the GRF for hundreds of TF-target relationships
we will dramatically improve our understanding of this critically important aspect of how gene expression works
and gain unprecedented insight into the dynamic nature of the GRF in response to environmental change, which
should have impacts on many areas of biological science and especially human disease. Furthermore, this
project will provide dozens of undergraduate students the opportunity of engaging in a course-based research
project where they will participate in scientific discovery that yields skills in bioinformatics programming, training
in scientific thinking, writing experience, and ultimately result in authorship on generated manuscripts. Through
this student research experience, we aim to increase the retention of underrepresented groups in STEM, provide
transferrable scientific skills and begin building human network connections for the next generation of scientists.