Investigations of Inositol Phosphate-Mediated Transcription

Abstract

<p>Inositol phosphates (IPs) are eukaryotic signaling molecules that play important roles in a wide range of biological processes. IPs are required for embryonic development and patterning, insulin secretion, the regulation of telomere length, proper progression through the cell cycle, and the regulation of ion channels. This work uses the yeast Saccharomyces cerevisiae as a model system for investigating the functions of IPs and focuses on the transcriptional regulation of the gene encoding the secreted mating pheromone MF&alpha;2 by the IP kinase Ipk2 (also called Arg82, ArgR3, and IPMK). This work shows that Ipk2 has both kinase-dependent and kinase-independent functions in regulating the transcription of MF&alpha;2. Transcription of MF&alpha;2 is also dependent upon the integrity of an Mcm1-binding site in its promoter. This is the first description of a role for this binding site in the transcription of MF&alpha;2. </p><p><italic>In vivo</italic> and <italic>in vitro</italic> screening approaches to identify additional factors associated with MF&alpha;2 expression or with IP biology generally are also described. These unbiased approaches provide some valuable insight for further investigations.</p>