Date of Award

2020

Document Type

Dissertation

Degree Name

Ph.D.

Department

Biological Sciences

First Advisor

David Patterson

Second Advisor

Daniel Linseman

Third Advisor

Gareth Eaton

Fourth Advisor

Joseph K. Angleson

Fifth Advisor

Dinah Loerke

Sixth Advisor

Ali Azadani

Keywords

De novo purine synthesis, Metabolomics, Purine, Transcriptomics

Abstract

Purines are a class of nitrogenous bases and are essential small molecules to life. Purines are used within the cell as genetic information carriers, energy currency, signaling molecules, and cofactors for multiple processes. They are formed through de novo and salvage pathways found in cells across the phylogenetic tree. The substrates of enzymes within de novo purine synthesis are known to influence other processes within the cell, such as energy homeostasis. In humans, de novo purine synthesis disorders are rare, with around 100 people identified. These patients exhibit a range of phenotypes, with varying degrees of mental retardation, seizure activity, facial and body dysmorphic features, autistic features, respiratory failure, and congenital blindness. To date, the explanation of phenotypes associated with these disorders remains elusive and as such, no effective therapeutic has been identified. Rare disorders are often caused by a single genetic mutation and studying rare disorders can providing key insight into processes regulated by that specific enzyme. In this body of work, I use transcriptomic profiling techniques to provide cellular and organismal process characterization of a novel cellular model of de novo purine deficiency in three CRISPR generated HeLa cell lines. I examine the de novopurine synthesis enzymes ADSL, GART, and ATIC. Processes identified influenced by de novopurine dysregulation identified are focused around neural, embryonic, organ, and placental development, epithelial to mesenchymal transition, fatty acid and inflammatory response, muscle function, tumorigenesis, oxidative stress responses, as well as TGFβ/SMAD signaling among others. Metabolomic profiling was employed to bolster transcriptomic findings, with aberrations of metabolic pathways involved in energy production, vitamin B6 and B5 metabolism, oxidative stress responses, lipids, amino acids, among others. My findings highlight areas in which de novo purine synthesis enzymes influence cellular processes responsible for cellular and organismal function and represent novel avenues of continued research.

Publication Statement

Copyright is held by the author. User is responsible for all copyright compliance.

Provenance

Received from ProQuest

Rights holder

Randall Craig Mazzarino

File size

237 p.

File format

application/pdf

Language

en

Discipline

Cellular biology, Biology, Biophysics

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