Main content area

Two apextrin-like proteins mediate extracellular and intracellular bacterial recognition in amphioxus

Huang, Guangrui, Huang, Shengfeng, Yan, Xinyu, Yang, Ping, Li, Jun, Xu, Weiya, Zhang, Lingling, Wang, Ruihua, Yu, Yingcai, Yuan, Shaochun, Chen, Shangwu, Luo, Guangbin, Xu, Anlong
Proceedings of the National Academy of Sciences of the United States of America 2014 v.111 no.37 pp. 13469-13474
extracellular space, immune response, microorganisms, pathogens, proteins
Significance Microbial specific pathogen-associated molecular patterns (PAMPs) constitute a key feature by which a host organism detects the presence of microbes and mounts specific immune responses. Here, we report the discovery of two proteins (bjALP1 and 2) that interact with muramyl dipeptide, a pan-bacterial specific PAMP via a novel pattern recognition domain ApeC. Our studies have revealed that bjALP1 is a secreted immune effector, whereas bjALP2 functions as an intracellular pattern recognition receptor (PRR), both having an important role in protecting the host from microbial pathogens. Specifically, bjAPL1 functions in the extracellular space to reduce the harmful effect of pathogenic microbes, whereas bjALP2 functions as a PRR that serves as a sentinel for intracellular bacterial invasion.