Date of Award

Spring 1-1-2017

Document Type


Degree Name

Doctor of Philosophy (PhD)

First Advisor

Amy E. Palmer

Second Advisor

Leslie A. Leinwand

Third Advisor

James A. Goodrich

Fourth Advisor

Ralph Jimenez

Fifth Advisor

Gia K. Voeltz


Zinc (Zn2+) is an essential micronutrient for human health. However, excess Zn2+ is toxic and Zn2+ deficiency can be fatal, so the concentration of this ion must be carefully controlled within cells. Highlighting the importance of Zn2+ is the observation that approximately 10 % of the genes in the human genome potentially code for a Zn2+-binding protein. The Palmer lab has developed a suite of genetically-encoded biosensors for Zn2+ that use Förster Resonance Energy Transfer (FRET) to provide a readout of Zn2+ concentration within human cells. Measurements with these sensors have revealed heterogeneous distribution of Zn2+ throughout cells, however we have begun to realize that some subcellular environments, particularly in the endoplasmic reticulum (ER), can impact the functionality of these sensors. Here, we present framework to critically evaluate the performance of genetically-encoded FRET sensors in different cellular environments. Progress towards engineering an improved ER Zn2+ sensor by microfluidic cytometry is also discussed. Additionally, we demonstrate how cytosolic and ER Zn2+ levels can be altered by genetic manipulation of a Zn2+ transport protein located on the ER membrane.