Wild-type Shadoo proteins convert to amyloid-like forms under native conditions

作者：Daude Nathalie; Ng Vivian; Watts Joel C; Genovesi Sacha; Glaves John Paul; Wohlgemuth Serene; Schmitt Ulms Gerold; Young Howard; McLaurin JoAnne; Fraser Paul E; Westaway David^*

来源：Journal of Neurochemistry, 2010, 113(1): 92-104.

DOI：10.1111/j.1471-4159.2010.06575.x

• fibrils
• hydrophobic domain
• misfolding
• prions
• protease-resistant

P>The cellular prion protein PrPC refolds into a beta-sheet enriched, infectivity-associated form called PrPSc. Shadoo (Sho) is a newly discovered glycoprotein that is also expressed in the adult brain. Wild type (wt) mouse Sho consists of an arginine-rich region, a hydrophobic central domain of five tandem A/LAAG amino acid repeats R1-R5 with similarity to the hydrophobic domain of PrPC, and a C-terminal domain with one N-linked carbohydrate. As some alanine-rich proteins and PrP with a shortened C-terminal domain form amyloid we investigated conformational properties of wt Sho and polymorphic variants with insertion/deletions centered on R3. Recombinant mouse and sheep Sho converted to an amyloid-like form without recourse to chemical denaturation or acidification. For wt proteins this transition was marked by increased thioflavin T binding, Congo red staining, presence of fibrillar structures by electron microscopy, formation of sodium dodecyl sulfate-resistant complexes and the generation of a C-terminal proteinase K resistant core of 5-8 kDa. Variant Sho proteins differing within the R1-R5 region exhibited most but not all of these properties. Our studies define a proteinase K -resistant signature fragment for the amyloid fold of Sho and raise the question of a physiological role for this form of the wt protein.

• 出版日期2010-4