Journal Article

Vibrioeffector protein VopQ inhibits fusion of V-ATPase–containing membranes

Carpinone, Emily M., Starai, Vincent J., O’Brien, Kevin M., Bennett, Terry L., Sreelatha, Anju, Jordan, Kamyron D., Orth, Kim, Burdette, Dara L.

2015

Overview

Vesicle fusion governs many important biological processes, and imbalances in the regulation of membrane fusion can lead to a variety of diseases such as diabetes and neurological disorders. Here we show that theVibrio parahaemolyticuseffector protein VopQ is a potent inhibitor of membrane fusion based on an in vitro yeast vacuole fusion model. Previously, we demonstrated that VopQ binds to the Vₒ domain of the conserved V-type H⁺-ATPase (V-ATPase) found on acidic compartments such as the yeast vacuole. VopQ forms a nonspecific, voltage-gated membrane channel of 18 Å resulting in neutralization of these compartments. We now present data showing that VopQ inhibits yeast vacuole fusion. Furthermore, we identified a unique mutation in VopQ that delineates its two functions, deacidification and inhibition of membrane fusion. The use of VopQ as a membrane fusion inhibitor in this manner now provides convincing evidence that vacuole fusion occurs independently of luminal acidification in vitro.

• Publisher: National Academy of Sciences