title: Influence of Ca2+ and pH on the folding of the prourotensin II precursor.
abstract: Proper folding is a crucial step for the trafficking of proteins through the secretory pathway. We hypothesized that the secretory granules of endocrine cells provide optimal folding conditions of prohormone precursors for cleavage. Here, using circular dichroism and in vitro processing on purified prourotensin II (ProUII), we show that the precursor undergoes pH- and Ca(2+)-dependent conformational and stability changes. ProUII has a stable tertiary structure at pH 5.5 in presence of Ca(2+) and is correctly cleaved in these conditions by prohormone convertases. Taken together, our results support the notion that precursors may need to be optimally folded in the lumen of secretory granules for their processing.
authors: Department of Pharmacology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Québec, Canada.
authors: Josée
authors: J
authors: Bilodeau
authors: Antoine
authors: A
authors: Désilets
authors: François-Olivier
authors: FO
authors: McDuff
authors: Caroline
authors: C
authors: St-Pierre
authors: Elie
authors: E
authors: Barbar
authors: Richard
authors: R
authors: Leduc
authors: Pierre
authors: P
authors: Lavigne