Date of Award

2015

Degree Name

Chemistry

College

College of Science

Type of Degree

M.S.

Document Type

Thesis

First Advisor

Bin Wang

Second Advisor

Michael Norton

Third Advisor

Leslie Frost

Abstract

Iron is a widely distributed metal found in almost every physiological system in nature, thus being an essential part of life. Iron homeostasis in the human body must be tightly regulated as iron is both beneficial and harmful to different cellular processes. Ferritin is a protein that has a prominent role in maintaining iron homeostasis via iron sequestration. Additionally, this protein itself is regulated by the Iron Responsive Element (IRE) and its interaction with an apoaconitase protein or the Iron Regulatory Protein (IRP). The binding of the IRP to this IRE, located on the 5’ untranslated stem loop region of the ferritin mRNA, will inhibit translation into Ferritin creating an additional major mechanism to control cellular iron metabolism. Previous literature had indicated that divalent metal ions (Fe2+, Mn2+) and small molecule drugs can interrupt the binding of the IRE-IRP complex, specifically by altering the secondary structure of the IRE. Following this model, we conducted a series of experiments using Atomic Force Microscopy (AFM), Electrophoretic Mobility Shift Assays (EMSAs), and high-throughput Selective 2’Hydroxyl Acylation analyzed by Primer Extension (hSHAPE) Chemistry to observe effects from Mn2+ on already bound IRE-IRP complexes. The results concluded the Mn2+ had little to no effect on an already bound IRE-IRP complex. However upon changing our experimental procedure, EMSA experiments show pre-incubating the IRE and IRP separately in Mn2+ prior to binding affects complex formation. The results also indicated it is the IRP being affected by the Mn2+ and not the IRE, which contradicts the previous model.

Subject(s)

Iron -- Research.

Ferritin -- Research.

Iron in the body -- Research.

Download

Share

COinS