biochemical properties of gastrokine-1 purified from chicken gizzard smooth muscle的生化性质gastrokine-1纯化鸡肫平滑肌.pdf

Biochemical Properties of Gastrokine-1 Purified from Chicken Gizzard Smooth Muscle ´ ´ Karim Hnia, Cecile Notarnicola, Pascal de Santa Barbara, Gerald Hugon, Franc¸ois Rivier, Dalila Laoudj- Chenivesse, Dominique Mornet* ´ INSERM ERI 25 ‘‘Muscle et Pathologies’’, Universite Montpellier 1, EA 4202, CHU Arnaud de Villeneuve, Montpellier, France Abstract The potential role and function of gastrokine-1 (GNK1) in smooth muscle cells is investigated in this work by first establishing a preparative protocol to obtain this native protein from freshly dissected chicken gizzard. Some unexpected biochemical properties of gastrokine-1 were deduced by producing specific polyclonal antibody against the purified protein. We focused on the F-actin interaction with gastrokine-1 and the potential role and function in smooth muscle contractile properties. Background: GNK1 is thought to provide mucosal protection in the superficial gastric epithelium. However, the actual role of gastrokine-1 with regards to its known decreased expression in gastric cancer is still unknown. Recently, trefoil factors (TFF) were reported to have important roles in gastric epithelial regeneration and cell turnover, and could be involved in GNK1 interactions. The aim of this study was to evaluate the role and function of GNK1 in smooth muscle cells. Methodology/Principal Findings: From fresh chicken gizzard smooth muscle, an original purification procedure was used to purify a heat soluble 20 kDa protein that was sequenced and found to correspond to the gastrokine-1 protein sequence containing one BRICHOS domain and at least two or possibly three transmembrane regions. The purified protein was us