Modelling the role of the Hsp70/Hsp90 system in the maintenance of protein homeostasis.

Neurodegeneration is an age-related disorder which is characterised by the accumulation of aggregated protein and neuronal cell death. There are many different neurodegenerative diseases which are classified according to the specific proteins involved and the regions of the brain which are affected....

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Main Authors: Carole J Proctor, Ian A J Lorimer
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2011-01-01
Series:PLoS ONE
Online Access:http://europepmc.org/articles/PMC3137010?pdf=render
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author Carole J Proctor
Ian A J Lorimer
author_facet Carole J Proctor
Ian A J Lorimer
author_sort Carole J Proctor
collection DOAJ
description Neurodegeneration is an age-related disorder which is characterised by the accumulation of aggregated protein and neuronal cell death. There are many different neurodegenerative diseases which are classified according to the specific proteins involved and the regions of the brain which are affected. Despite individual differences, there are common mechanisms at the sub-cellular level leading to loss of protein homeostasis. The two central systems in protein homeostasis are the chaperone system, which promotes correct protein folding, and the cellular proteolytic system, which degrades misfolded or damaged proteins. Since these systems and their interactions are very complex, we use mathematical modelling to aid understanding of the processes involved. The model developed in this study focuses on the role of Hsp70 (IPR00103) and Hsp90 (IPR001404) chaperones in preventing both protein aggregation and cell death. Simulations were performed under three different conditions: no stress; transient stress due to an increase in reactive oxygen species; and high stress due to sustained increases in reactive oxygen species. The model predicts that protein homeostasis can be maintained during short periods of stress. However, under long periods of stress, the chaperone system becomes overwhelmed and the probability of cell death pathways being activated increases. Simulations were also run in which cell death mediated by the JNK (P45983) and p38 (Q16539) pathways was inhibited. The model predicts that inhibiting either or both of these pathways may delay cell death but does not stop the aggregation process and that eventually cells die due to aggregated protein inhibiting proteasomal function. This problem can be overcome if the sequestration of aggregated protein into inclusion bodies is enhanced. This model predicts responses to reactive oxygen species-mediated stress that are consistent with currently available experimental data. The model can be used to assess specific interventions to reduce cell death due to impaired protein homeostasis.
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spelling doaj.art-4e64a6a62b90439781a547aaec98936b2022-12-21T20:06:37ZengPublic Library of Science (PLoS)PLoS ONE1932-62032011-01-0167e2203810.1371/journal.pone.0022038Modelling the role of the Hsp70/Hsp90 system in the maintenance of protein homeostasis.Carole J ProctorIan A J LorimerNeurodegeneration is an age-related disorder which is characterised by the accumulation of aggregated protein and neuronal cell death. There are many different neurodegenerative diseases which are classified according to the specific proteins involved and the regions of the brain which are affected. Despite individual differences, there are common mechanisms at the sub-cellular level leading to loss of protein homeostasis. The two central systems in protein homeostasis are the chaperone system, which promotes correct protein folding, and the cellular proteolytic system, which degrades misfolded or damaged proteins. Since these systems and their interactions are very complex, we use mathematical modelling to aid understanding of the processes involved. The model developed in this study focuses on the role of Hsp70 (IPR00103) and Hsp90 (IPR001404) chaperones in preventing both protein aggregation and cell death. Simulations were performed under three different conditions: no stress; transient stress due to an increase in reactive oxygen species; and high stress due to sustained increases in reactive oxygen species. The model predicts that protein homeostasis can be maintained during short periods of stress. However, under long periods of stress, the chaperone system becomes overwhelmed and the probability of cell death pathways being activated increases. Simulations were also run in which cell death mediated by the JNK (P45983) and p38 (Q16539) pathways was inhibited. The model predicts that inhibiting either or both of these pathways may delay cell death but does not stop the aggregation process and that eventually cells die due to aggregated protein inhibiting proteasomal function. This problem can be overcome if the sequestration of aggregated protein into inclusion bodies is enhanced. This model predicts responses to reactive oxygen species-mediated stress that are consistent with currently available experimental data. The model can be used to assess specific interventions to reduce cell death due to impaired protein homeostasis.http://europepmc.org/articles/PMC3137010?pdf=render
spellingShingle Carole J Proctor
Ian A J Lorimer
Modelling the role of the Hsp70/Hsp90 system in the maintenance of protein homeostasis.
PLoS ONE
title Modelling the role of the Hsp70/Hsp90 system in the maintenance of protein homeostasis.
title_full Modelling the role of the Hsp70/Hsp90 system in the maintenance of protein homeostasis.
title_fullStr Modelling the role of the Hsp70/Hsp90 system in the maintenance of protein homeostasis.
title_full_unstemmed Modelling the role of the Hsp70/Hsp90 system in the maintenance of protein homeostasis.
title_short Modelling the role of the Hsp70/Hsp90 system in the maintenance of protein homeostasis.
title_sort modelling the role of the hsp70 hsp90 system in the maintenance of protein homeostasis
url http://europepmc.org/articles/PMC3137010?pdf=render
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