AUTHORS
Vanessa M. D’Costa, Etienne Coyaud, Kirsten C. Boddy, Estelle M. N. Laurent, Jonathan St-Germain, Taoyingnan Li, Sergio Grinstein, Brian Raught, John H. Brumell
ABSTRACT
Many bacterial pathogens express virulence proteins that are translocated into host cells (herein referred to as effectors), where they can interact with target proteins to manipulate host cell processes. These effector–host protein interactions are often dynamic and transient in nature, making them difficult to identify using traditional interaction-based methods. Here, we performed a systematic comparison between proximity-dependent biotin labelling (BioID) and immunoprecipitation coupled with mass spectrometry to investigate a series of Salmonella type 3 secreted effectors that manipulate host intracellular trafficking (SifA, PipB2, SseF, SseG and SopD2). Using BioID, we identified 632 candidate interactions with 381 unique human proteins, collectively enriched for roles in vesicular trafficking, cytoskeleton components and transport activities. From the subset of proteins exclusively identified by BioID, we report that SifA interacts with BLOC-2, a protein complex that regulates dynein motor activity. We demonstrate that the BLOC-2 complex is necessary for SifA-mediated positioning of Salmonella-containing vacuoles, and affects stability of the vacuoles during infection. Our study provides insight into the coordinated activities of Salmonella type 3 secreted effectors and demonstrates the utility of BioID as a powerful, complementary tool to characterize effector–host protein interactions.
Click here to read the article, published in Nature.
