Date of Award

Summer 8-11-2015

Degree Type


Degree Name



Biological Sciences

Major Professor

Dr. Mary J Clancy

Second Advisor

Dr. Zhengchang Liu

Third Advisor

Dr. Wendy Schluchter


In the yeast Saccharomyces cerevisiae, the IME4 methyltransferase, interacts genetically with methyl binding protein, Pho92, to affect the expression of PHO regulon target genes. Cells mutant in IME4 or PHO92 show increases in the RNA abundance of PHO regulon target genes. The increase in the RNA abundance of the PHO regulon target genes is not additive in the cells double mutant in IME4 and PHO92. Hence, Ime4 and Pho92 interact in a single pathway in PHO regulon. Surprisingly, cells overexpressing IME4 and MUM2 shows increase in some PHO regulon target genes, indicating that IME4 affects the PHO regulon target genes through multiple mechanisms in different conditions. A promoter swap experiment revealed that one of the PHO regulon mRNAs that codes for phosphatase, PHO5, is a direct target of Ime4. Further experiments are required to examine whether the same is true for all PHO regulon mRNAs.


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