Document Type

Campus-Only Access for Five (5) Years

Embargo Period

6-4-2015

Degree Program

Microbiology

Degree Type

Master of Science (M.S.)

Year Degree Awarded

2015

Month Degree Awarded

February

Advisor Name

John

Advisor Middle Initial

M

Advisor Last Name

Lopes

Abstract

This study focuses on understanding the mechanisms of expression control of a phospholipid biosynthetic gene, INO1. This study also includes investigation into transcriptional regulation of SNA3, a gene in tandem upstream of INO1.

INO1 expression is a prevailing model for transcription studies. INO1 is repressed under growth conditions with inositol and derepressed by two transcription activators, Ino2 and Ino4, when inositol is absent. Coordination of the centromeric binding factor, Cbf1, with Ino2 and Ino4 is required for efficient derepression of INO1. Transcription of the INO1 adjacent SNA3 gene is also influenced by inositol. INO1 and SNA3 are co-regulated by Cbf1, Ino2 and Ino4. However, the mechanism of this co-regulation is not fully understood.

A separate aspect of INO1 expression is its growth phase regulation. Under inositol depleted conditions, the expression of INO1 increases during log phase and decreases during stationary phase. Most genes in yeast are believed to be expressed at a constant level through all growth phases. It is unclear how INO1 growth phase regulation takes place.

The first part of my work focused on exploring the mechanism through which Cbf1, Ino2 and Ino4 control the inositol-mediated regulation of INO1 and SNA3. This included determining the necessity of the Cbf1 binding site for Ino2 and Ino4 binding, as well as for the inositol mediated regulation of INO1 and SNA3. The second part of my work focused on understanding the growth phase regulation of INO1. This includes examining the expression of INO1 in individual cells in a growing population.

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