title: Targeting Hsp90/Hsp70-based protein quality control for treatment of adult onset neurodegenerative diseases.
abstract: Currently available therapies for adult onset neurodegenerative diseases provide symptomatic relief but do not modify disease progression. Here we explore a new neuroprotective approach based on drugs targeting chaperone-directed protein quality control. Critical target proteins that unfold and aggregate in these diseases, such as the polyglutamine androgen receptor in spinal and bulbar muscular atrophy, huntingtin in Huntington's disease, α-synuclein in Parkinson's disease, and tau in Alzheimer's disease, are client proteins of heat shock protein 90 (Hsp90), and their turnover is regulated by the protein quality control function of the Hsp90/Hsp70-based chaperone machinery. Hsp90 and Hsp70 have opposing effects on client protein stability in protein quality control; Hsp90 stabilizes the clients and inhibits their ubiquitination, whereas Hsp70 promotes ubiquitination dependent on CHIP (C terminus of Hsc70-interacting protein) and proteasomal degradation. We discuss how drugs that modulate proteostasis by inhibiting Hsp90 function or promoting Hsp70 function enhance the degradation of the critical aggregating proteins and ameliorate toxic symptoms in cell and animal disease models.
authors.affiliation: Department of Pharmacology and.
authors.forename: William B
authors.initials: WB
authors.lastname: Pratt
authors.forename: Jason E
authors.initials: JE
authors.lastname: Gestwicki
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Osawa
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Lieberman
mesh_terms: D000328:Adult; D017668:Age of Onset; D000818:Animals; D018840:HSP70 Heat-Shock Proteins / Q000819:agonists* / Q000378:metabolism; D018841:HSP90 Heat-Shock Proteins / Q000037:antagonists & inhibitors* / Q000378:metabolism; D006801:Humans; D009420:Nervous System / Q000187:drug effects* / Q000378:metabolism / Q000503:physiopathology; D019636:Neurodegenerative Diseases / Q000175:diagnosis / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D018696:Neuroprotective Agents / Q000627:therapeutic use*; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D011489:Protein Denaturation; D017510:Protein Folding; D055550:Protein Stability; D015398:Signal Transduction / Q000187:drug effects; D044767:Ubiquitin-Protein Ligases / Q000378:metabolism; D054875:Ubiquitination
chemical_list: D018840:HSP70 Heat-Shock Proteins; D018841:HSP90 Heat-Shock Proteins; D018696:Neuroprotective Agents; C467728:STUB1 protein, human; D044767:Ubiquitin-Protein Ligases; D046988:Proteasome Endopeptidase Complex
keywords: CHIP; neurodegeneration; proteasome; protein aggregation; ubiquitination