Document Detail


Hsp70- and Hsp90-mediated proteasomal degradation underlies TPI sugarkill pathogenesis in Drosophila.
MedLine Citation:
PMID:  20727972     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Triosephosphate isomerase (TPI) deficiency is a severe glycolytic enzymopathy that causes progressive locomotor impairment and neurodegeneration, susceptibility to infection, and premature death. The recessive missense TPI(sugarkill) mutation in Drosophila melanogaster exhibits phenotypes analogous to human TPI deficiency such as progressive locomotor impairment, neurodegeneration, and reduced life span. We have shown that the TPI(sugarkill) protein is an active stable dimer; however, the mutant protein is turned over by the proteasome reducing cellular levels of this glycolytic enzyme. As proteasome function is often coupled with molecular chaperone activity, we hypothesized that TPI(sugarkill) is recognized by molecular chaperones that mediate the proteasomal degradation of the mutant protein. Coimmunoprecipitation data and analyses of TPI(sugarkill) turnover in animals with reduced or enhanced molecular chaperone activity indicate that both Hsp90 and Hsp70 are important for targeting TPI(sugarkill) for degradation. Furthermore, molecular chaperone and proteasome activity modified by pharmacological or genetic manipulations resulted in improved TPI(sugarkill) protein levels and rescue some but not all of the disease phenotypes suggesting that TPI deficiency pathology is complex. Overall, these data demonstrate a surprising role for Hsp70 and Hsp90 in the progression of neural dysfunction associated with TPI deficiency.
Authors:
Stacy L Hrizo; Michael J Palladino
Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't     Date:  2010-08-19
Journal Detail:
Title:  Neurobiology of disease     Volume:  40     ISSN:  1095-953X     ISO Abbreviation:  Neurobiol. Dis.     Publication Date:  2010 Dec 
Date Detail:
Created Date:  2010-10-15     Completed Date:  2011-01-25     Revised Date:  2011-12-21    
Medline Journal Info:
Nlm Unique ID:  9500169     Medline TA:  Neurobiol Dis     Country:  United States    
Other Details:
Languages:  eng     Pagination:  676-83     Citation Subset:  IM    
Copyright Information:
Copyright © 2010 Elsevier Inc. All rights reserved.
Affiliation:
Deparment of Pharmacology & Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA.
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MeSH Terms
Descriptor/Qualifier:
Animals
Blotting, Western
Drosophila melanogaster
HSP70 Heat-Shock Proteins / metabolism*
HSP90 Heat-Shock Proteins / metabolism*
Immunoprecipitation
Motor Activity / genetics
Mutation, Missense
Proteasome Endopeptidase Complex / metabolism*
Triose-Phosphate Isomerase / genetics,  metabolism*
Grant Support
ID/Acronym/Agency:
R01 AG025046-05/AG/NIA NIH HHS; R01 AG027453-02/AG/NIA NIH HHS; R01AG025046/AG/NIA NIH HHS; R01AG027453/AG/NIA NIH HHS
Chemical
Reg. No./Substance:
0/HSP70 Heat-Shock Proteins; 0/HSP90 Heat-Shock Proteins; EC 3.4.25.1/Proteasome Endopeptidase Complex; EC 5.3.1.1/Triose-Phosphate Isomerase

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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