Dr Tyler Howell Bray

Dr Tyler Howell Bray's Qualifications (4)

Fellow of the Higher Education Academy
FHEA

Status Complete

Part Time Yes

Years 2016 - 2017

Awarding Institution Canterbury Christ Church University

Status	Complete
Part Time	Yes
Years	2016 - 2017
Awarding Institution	Canterbury Christ Church University

Post Graduate Certificate in Academic Practise
PGCert

Status Complete

Part Time Yes

Years 2016 - 2017

Awarding Institution Canterbury Christ Church University

Status	Complete
Part Time	Yes
Years	2016 - 2017
Awarding Institution	Canterbury Christ Church University

Biological Science
PhD / DPhil

Status Complete

Part Time Yes

Years 2014 - 2019

Project Title Investigating the metabolic consequences of protein misfolding in the yeast Saccharomyces cerevisiae

Project Description Protein misfolding disease can be loosely separated into two groups: the non-transmissible amyloid diseases (e.g. Alzheimer's and Huntington's) and the transmissible amyloid diseases (e.g. Scrapie and Kuru). The amyloid and prion diseases present the same misfolding mechanism and thus prions can be used to recapitulate the biochemical hallmarks of amyloid disease. The budding yeast Saccharomyces cerevisiae is a popular and valuable model for the study of prions. Whilst much progress has been made over the last century, our understanding of the specific mechanisms which underpin amyloid and prion disease is still incomplete. The aim of this study was to enhance current understanding about the metabolic consequence of misfolded proteins. Yeast strains carrying different conformational variants of the known prion forming Rnq1 protein were used to obtain metabolic profiles and identify key perturbations. This approach began by determining a metabolomic method suitable for use in S. cerevisiae. Ultra-High-Performance Liquid Chromatography Mass Spectrometry (UHPLC-MS) was used to establish a sample preparation method that accurately revealed the metabolic state of S. cerevisiae. It was found that culturing yeast cells in a liquid medium and extracting metabolites with an acetonitrile: water (50:50) mix most accurately reported on the biological conditions imposed. The endogenous cellular role of the Rnq1 protein was studied, using a strain of S. cerevisiae in which the RNQ1 gene had been deleted (?rnq1). A robust data analysis methodology was established and applied to the data obtained, utilising cross comparison of two widely used metabolomics analysis programs. Then, biomarkers and metabolic pathways associated with the presence of the Rnq1 protein were investigated, comparing [RNQ+] and [rnq- ] cells. The toxicity of Rnq1 protein overexpression in a [RNQ+] background was explored, via the expression of the RNQ1 gene. These studies reveal that the presence of the Rnq1 protein downregulates the ubiquinone biosynthesis pathways within cells, suggesting that the Rnq1 protein may play a lipid/mevalonate-based cytoprotective role as a regulator of ubiquinone production. Distinct perturbations in sphingolipid metabolism were observed in [RNQ+] cells, with significant downregulation in metabolites within these pathways, providing new evidence of metabolic similarities between yeast and mammalian cells as a consequence of prion presence. Metabolic perturbations relating to general and specific stress responses caused by oxidative stress in the presence and absence of prions were also obtained. This work establishes the application of metabolomics as a tool to investigate prion-based phenomena.

Awarding Institution Canterbury Christ Church University

Status	Complete
Part Time	Yes
Years	2014 - 2019
Project Title	Investigating the metabolic consequences of protein misfolding in the yeast Saccharomyces cerevisiae
Project Description	Protein misfolding disease can be loosely separated into two groups: the non-transmissible amyloid diseases (e.g. Alzheimer's and Huntington's) and the transmissible amyloid diseases (e.g. Scrapie and Kuru). The amyloid and prion diseases present the same misfolding mechanism and thus prions can be used to recapitulate the biochemical hallmarks of amyloid disease. The budding yeast Saccharomyces cerevisiae is a popular and valuable model for the study of prions. Whilst much progress has been made over the last century, our understanding of the specific mechanisms which underpin amyloid and prion disease is still incomplete. The aim of this study was to enhance current understanding about the metabolic consequence of misfolded proteins. Yeast strains carrying different conformational variants of the known prion forming Rnq1 protein were used to obtain metabolic profiles and identify key perturbations. This approach began by determining a metabolomic method suitable for use in S. cerevisiae. Ultra-High-Performance Liquid Chromatography Mass Spectrometry (UHPLC-MS) was used to establish a sample preparation method that accurately revealed the metabolic state of S. cerevisiae. It was found that culturing yeast cells in a liquid medium and extracting metabolites with an acetonitrile: water (50:50) mix most accurately reported on the biological conditions imposed. The endogenous cellular role of the Rnq1 protein was studied, using a strain of S. cerevisiae in which the RNQ1 gene had been deleted (?rnq1). A robust data analysis methodology was established and applied to the data obtained, utilising cross comparison of two widely used metabolomics analysis programs. Then, biomarkers and metabolic pathways associated with the presence of the Rnq1 protein were investigated, comparing [RNQ+] and [rnq- ] cells. The toxicity of Rnq1 protein overexpression in a [RNQ+] background was explored, via the expression of the RNQ1 gene. These studies reveal that the presence of the Rnq1 protein downregulates the ubiquinone biosynthesis pathways within cells, suggesting that the Rnq1 protein may play a lipid/mevalonate-based cytoprotective role as a regulator of ubiquinone production. Distinct perturbations in sphingolipid metabolism were observed in [RNQ+] cells, with significant downregulation in metabolites within these pathways, providing new evidence of metabolic similarities between yeast and mammalian cells as a consequence of prion presence. Metabolic perturbations relating to general and specific stress responses caused by oxidative stress in the presence and absence of prions were also obtained. This work establishes the application of metabolomics as a tool to investigate prion-based phenomena.
Awarding Institution	Canterbury Christ Church University

Animal Science
BSc

Status Complete

Years 2010 - 2014

Awarding Institution Canterbury Christ Church University