Roles of protein sequence and cell environment in cross-species prion transmission and amyloid interference

Bruce, Kathryn Lyn

Title:

Roles of protein sequence and cell environment in cross-species prion transmission and amyloid interference

dc.contributor.advisor	Chernoff, Yury O.
dc.contributor.author	Bruce, Kathryn Lyn
dc.contributor.committeeMember	Lobachev, Kirill S.
dc.contributor.committeeMember	Storici, Francesca
dc.contributor.committeeMember	Bommarius, Andreas S.
dc.contributor.committeeMember	Gleason, Michael L.
dc.contributor.department	Biology
dc.date.accessioned	2014-08-27T13:39:00Z
dc.date.available	2014-08-27T13:39:00Z
dc.date.created	2014-08
dc.date.issued	2014-07-08
dc.date.submitted	August 2014
dc.date.updated	2014-08-27T13:39:00Z
dc.description.abstract	Proteinaceous infectious particles, termed 'prions' are self-perpetuating protein isoforms that transmit neurodegenerative diseases in mammals and phenotypic traits in yeast. Each conformational variant of a prion protein is faithfully propagated to a homologous protein in the same cell environment. However, a reduction in the efficiency of prion transmission between different species is often observed and is termed "species barrier". Prion transmission to a heterologous protein may, in some cases, permanently change the structure of the prion variant, and divergent proteins may interfere with prion propagation in a species-specific manner. To identify the importance of both protein sequence and the cell environment on prion interference and cross-species transmission, we employed heterologous Sup35 proteins from three Saccharomyces sensu stricto species: Saccharomyces cerevisiae (Sc), Saccharomyces paradoxus (Sp), and Saccharomyces bayanus (Sb). We performed our experiments in two different cell environments (Sc and Sp). Our data show that Sup35 from one species can form a prion in another, and we employed a transfection procedure to perform cross-species transfer of the prion. Using a shuffle procedure, we demonstrate that the specificity of prion transmission is determined by the protein itself rather than the cell environment. Interestingly, we noted that variant-specific prion patterns can be altered irreversibly during cross-species transmission through S. bayanus module II. We further show that prion interference does not always correlate with cross-species prion transmission, and the identity of particular regions or even a specific amino acid, rather than the overall level of PrD homology is crucial for determining cross-species transmission and interference. Lastly we provide evidence to suggest that prion interference is specific to the cell environment.
dc.description.degree	Ph.D.
dc.format.mimetype	application/pdf
dc.identifier.uri	http://hdl.handle.net/1853/52288
dc.language.iso	en_US
dc.publisher	Georgia Institute of Technology
dc.subject	Prion
dc.subject	Amyloid
dc.subject	Prion interference
dc.subject	Saccharomyces
dc.subject	Species barrier
dc.subject	Sup35
dc.title	Roles of protein sequence and cell environment in cross-species prion transmission and amyloid interference
dc.type	Text
dc.type.genre	Dissertation
dspace.entity.type	Publication
local.contributor.advisor	Chernoff, Yury O.
local.contributor.corporatename	College of Sciences
local.contributor.corporatename	School of Biological Sciences
relation.isAdvisorOfPublication	d9f3d192-f4c7-4db2-ace4-2baadbeb98b6
relation.isOrgUnitOfPublication	85042be6-2d68-4e07-b384-e1f908fae48a
relation.isOrgUnitOfPublication	c8b3bd08-9989-40d3-afe3-e0ad8d5c72b5
thesis.degree.level	Doctoral