Skip to main content

Characterisation of the function, sequence polymorphism and toxicity of the yeast Rnq1p prion protein

Staniforth, Gemma Louise (2011) Characterisation of the function, sequence polymorphism and toxicity of the yeast Rnq1p prion protein. Doctor of Philosophy (PhD) thesis, University of Kent. (doi:10.22024/UniKent/01.02.86487) (KAR id:86487)

PDF (590014.pdf)
Language: English


Download (56MB) Preview
[thumbnail of 590014.pdf]
Preview
This file may not be suitable for users of assistive technology.
Request an accessible format
XML Word Processing Document (DOCX) (590014_disc/Appendix - allele list.docx)
Language: English


Download (0B)
[thumbnail of 590014_disc/Appendix - allele list.docx]
This file may not be suitable for users of assistive technology.
Request an accessible format
XML Word Processing Document (DOCX) (590014_disc/Appendix - allele toxicity study.docx)
Language: English


Download (0B)
[thumbnail of 590014_disc/Appendix - allele toxicity study.docx]
This file may not be suitable for users of assistive technology.
Request an accessible format
XML Word Processing Document (DOCX) (590014_disc/Appendix - polymorphisms per residue, table.docx)
Language: English


Download (0B)
[thumbnail of 590014_disc/Appendix - polymorphisms per residue, table.docx]
This file may not be suitable for users of assistive technology.
Request an accessible format
Rich Text (RTF) (590014_disc/Appendix - rich text alignment of all construct sequences.rtf)
Language: English


Download (0B)
[thumbnail of 590014_disc/Appendix - rich text alignment of all construct sequences.rtf]
This file may not be suitable for users of assistive technology.
Request an accessible format
XML Word Processing Document (DOCX) (590014_disc/Appendix - RNQ1 construct sequences.docx)
Language: English


Download (0B)
[thumbnail of 590014_disc/Appendix - RNQ1 construct sequences.docx]
This file may not be suitable for users of assistive technology.
Request an accessible format
Other (590014_disc/Appendix - RNQ1 from all species aligned, rich text)
Language: English


Download (0B)
[thumbnail of 590014_disc/Appendix - RNQ1 from all species aligned, rich text]
This file may not be suitable for users of assistive technology.
Request an accessible format
XML Word Processing Document (DOCX) (590014_disc/Appendix - sequenced entry clones aligned, CLUSTALW.docx)
Language: English


Download (0B)
[thumbnail of 590014_disc/Appendix - sequenced entry clones aligned, CLUSTALW.docx]
This file may not be suitable for users of assistive technology.
Request an accessible format
HTML (590014_disc/Genetic modifiers - mHtt.pptx)
Language: English


Download (0B)
[thumbnail of 590014_disc/Genetic modifiers - mHtt.pptx]
This file may not be suitable for users of assistive technology.
Request an accessible format
HTML (590014_disc/Genetic modifiers - Rnq1.pptx)
Language: English


Download (0B)
[thumbnail of 590014_disc/Genetic modifiers - Rnq1.pptx]
This file may not be suitable for users of assistive technology.
Request an accessible format
HTML (590014_disc/Proteomics project - regulated proteins table.xlsx)
Language: English


Download (0B)
[thumbnail of 590014_disc/Proteomics project - regulated proteins table.xlsx]
This file may not be suitable for users of assistive technology.
Request an accessible format
Official URL
https://doi.org/10.22024/UniKent/01.02.86487

Abstract

The Saccharomyces cerevisiae Rnq 1 p prion protein plays an integral role in the dynamics of other aggregation-prone proteins, be they other prion proteins or glutamine-rich proteins. The conformational conversion of a prion protein to its prion state is often associated with changes to cellular physiology and two interesting questions arise from this. One, what impact do these physiological changes have on our ability to interpret experimental findings in this model organism? Two, are these changes non-random, representing a novel means of altering cellular physiology? An understanding of the cellular function of Rnq 1 P is important in addressing these questions. Further, the role of Rnq 1 P in its [PIN+] prion state as a universal catalyst for amyloid-formation provides a useful model for dissecting mechanisms of amyloid toxicity, and once again, cellular function is one parameter of multiple that determine the [mal toxicity profile of a protein. To identify a cellular function for Rnqlp both phenotypic assays and a mass spectrometry-based label-free quantitative proteomics analysis were performed. A role for Rnq 1 P as a negative regulator of translation termination was characterised

and eo-localisation of Rnq 1 p with P-bodies, tightly packed clusters of untranslating rnRNA, was observed indicating that Rnqlp is intimately associated with mRNA dynamics within the cell. Additionally, evidence for a role in the maintenance of mitochondrial respiratory capacity pertaining to ATP-generation is presented, along with indications that this latter role may be through transcriptional regulation. To further understand the mechanisms of toxic protein aggregation, two analyses were performed. One, a study on the impact of natural Rnqlp polymorphisms identified fifty-three novel RNQI alleles and sequence features affecting Rnq 1 P toxicity. Two, a screen for genetic modifiers of both Rnqlp and mutant huntingtin demonstrated the role of P-bodies and mRNA degradation pathways in modulating amyloid or glutamine-based toxicity, along with a possible role for energy. homeostasis. The results presented in this thesis provided new insight into the functional roles of Rnq 1 P within the cell, and consequently the possible impact on cellular physiology associated with Rnqlp's [pin-] to [PIN+] conversion, and also identified novel modulators of toxic aggregation events in the cell.

Item Type: Thesis (Doctor of Philosophy (PhD))
Thesis advisor: Tuite, Mick F.
DOI/Identification number: 10.22024/UniKent/01.02.86487
Additional information: This thesis has been digitised by EThOS, the British Library digitisation service, for purposes of preservation and dissemination. It was uploaded to KAR on 09 February 2021 in order to hold its content and record within University of Kent systems. It is available Open Access using a Creative Commons Attribution, Non-commercial, No Derivatives (https://creativecommons.org/licenses/by-nc-nd/4.0/) licence so that the thesis and its author, can benefit from opportunities for increased readership and citation. This was done in line with University of Kent policies (https://www.kent.ac.uk/is/strategy/docs/Kent%20Open%20Access%20policy.pdf). If you feel that your rights are compromised by open access to this thesis, or if you would like more information about its availability, please contact us at ResearchSupport@kent.ac.uk and we will seriously consider your claim under the terms of our Take-Down Policy (https://www.kent.ac.uk/is/regulations/library/kar-take-down-policy.html).
Subjects: Q Science
Divisions: Divisions > Division of Natural Sciences > Biosciences
SWORD Depositor: SWORD Copy
Depositing User: SWORD Copy
Date Deposited: 30 Oct 2019 13:54 UTC
Last Modified: 16 Dec 2021 17:33 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/86487 (The current URI for this page, for reference purposes)
  • Depositors only (login required):