Reconstitution of the cellular prion protein unfolding system using Hsp90 and its associated proteins

2014 Fiscal Year Final Research Report

• Project/Area Number: 24659422
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Neurology
• Research Institution: Tohoku University
• Principal Investigator: SAKASEGAWA Yuji 東北大学, 医学(系)研究科(研究院), 助教 (90418616)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: プリオン / 高次構造変換 / Hsp90

Outline of Final Research Achievements

To find cellular components affecting the conformation of the cellular prion protein (PrPC), we constructed an assay system measuring trypsin susceptibility of a recombinant cellular prion protein (rPrP). Consequently, we purified heat shock protein 90 (hsp90) from mouse neuroblastoma Neuro-2a cells. Hsp90 is a 90-kDa chaperone protein abundantly expressed in the cytosol, nuclear and extracellular space. In the in vitro assay, 1) Hsp90 unfolded the central region of rPrP, 2) the Hsp90 C-terminal chaperon domain is necessary for the unfolding activity; 3) any nucleotides such as ATP were not necessary for the unfolding activity; 3) Hsp90, however, unfolded the copper-loaded rPrP, which is more resistant to trypsin digestion, in the presence of ATP or ADP, but not AMP. In addition, we obtained novel Hsp90 C-terminal chaperon domain inhibitors, cisplatin derivatives, and confirmed that these inhibitors suppressed the prion formation in prion-infected neuroblastoma cells.

Free Research Field

生化学