Please use this identifier to cite or link to this item: https://hdl.handle.net/1959.11/8834
Title: An investigation of the relative contributions conveyed by heat shock proteins, trehalose, carbon source and gene expression to hyperthermia in 'Saccharomyces cerevisiae'
Contributor(s): Gross, Claudia (author); Watson, Kenneth  (supervisor)
Conferred Date: 1999
Copyright Date: 1998
Open Access: Yes
Handle Link: https://hdl.handle.net/1959.11/8834
Abstract: Intrinsic and heat shock induced thermotolerance of 'Saccharomyces cerevisiae' was investigated in cells grown on glucose (repressed) and acetate (derepressed) supplemented media. Heat shocked cells (37°C/30 min), in either medium, exhibited induced synthesis of heat shock proteins (hsps) and trehalose. In all cases, with the notable exception of repressed cells of a relatively thermosensitive strain (Ysen), heat shock acquisition of thermotolerance to a 50°C stress also occurred in the absence of protein synthesis and coincident decrease in trehalose accumulation. Results indicated that a marked increase in thermotolerance exhibited by derepressed cells compared with repressed cells was not closely correlated with levels of hsps or trehalose. It was concluded that mechanisms for intrinsic and induced thermotolerance appear to be different and that growth on acetate endows cells with a biochemical predisposition, other than hsps or trehalose. which confers intrinsic tolerance. Patterns of heat shock gene transcription and translation as well as trehalose content were investigated in both repressed and derepressed 'S cerevisiae' cells during heat shock, return of cells to 25°C (recovery) and subsequent exposure to a second heat shock (re-heat shock). Heat shocked cells, grown in either glucose or acetate supplemented media, initially acquired high thermotolerance to a 50°C heat stress, which was progressively lost when cultures were allowed to recover at 25°C and subsequently exposed to heat stress at 50°C. In all cases, with the notable exception of repressed cells of thermosensitive Ysen. inhibition of protein synthesis, and coincident decrease in trehalose accumulation, during the heat shock had little effect on the kinetics of loss of thermotolerance. Heat shock at 37°C elicited a marked increase in transcription and translation of genes encoding major lisps. During recovery at 25°C, both metabolic activities were suppressed followed by a gradual increase in hsp mRNA transcription to levels observed prior to heat shock. 'De novo' translation of hsp mRNAs, however, was no longer observed during the recovery phase. although immuno-detection analyses demonstrated persistence in cells of high levels of lisps 104, 90, 70 and 60 throughout the 240 min recovery period.
Publication Type: Thesis Doctoral
Rights Statement: Copyright 1998 - Claudia Gross
HERDC Category Description: T2 Thesis - Doctorate by Research
Appears in Collections:Thesis Doctoral

Files in This Item:
12 files
File Description SizeFormat 
open/SOURCE06.pdfThesis, part 33.37 MBAdobe PDF
Download Adobe
View/Open
open/SOURCE05.pdfThesis, part 22.27 MBAdobe PDF
Download Adobe
View/Open
open/SOURCE07.pdfThesis, part 44.25 MBAdobe PDF
Download Adobe
View/Open
open/SOURCE04.pdfThesis, part 12.72 MBAdobe PDF
Download Adobe
View/Open
open/SOURCE08.pdfThesis, part 54.8 MBAdobe PDF
Download Adobe
View/Open
open/SOURCE03.pdfAbstract2.33 MBAdobe PDF
Download Adobe
View/Open
1 2 Next
Show full item record

Page view(s)

1,214
checked on Jun 18, 2023

Download(s)

606
checked on Jun 18, 2023
Google Media

Google ScholarTM

Check


Items in Research UNE are protected by copyright, with all rights reserved, unless otherwise indicated.