Indexed on: 19 Oct '17Published on: 19 Oct '17Published in: FASEB journal : official publication of the Federation of American Societies for Experimental Biology
Zinc finger protein 365 (ZNF365) is widespread in animals, but its function and mechanism remains poorly defined. Here we clearly demonstrate that zebrafish ZNF365 is a newly identified LPS-binding protein capable of interacting with the gram-negative bacteria Escherichia coli, Vibrio anguillarum, and Aeromonas hydrophila, and functions as an antibacterial effector molecule capable of directly killing the bacteria. We also reveal that N-terminal residues 30-55 consisting of the ZnF_C2H2 domain are indispensable for ZNF365 antimicrobial activity. Importantly, microinjection of recombinant ZNF365 into early embryos significantly enhanced the resistance of the embryos against pathogenic A. hydrophila challenge, whereas down-regulation of ZNF365 by injection of znf365 morpholino into embryos considerably lowered their resistance against A. hydrophila challenge. Furthermore, the N-terminal peptide Z30-55 with in vitro antibacterial activity also promoted the resistance of embryos against A. hydrophila, but the peptide Z56-345 without in vitro antibacterial activity did not. Collectively, these results indicate that ZNF365 is a maternal LPS-binding protein that can protect the early embryos of zebrafish against pathogenic attacks, a novel role to be assigned to ZNF365 proteins. This work also provides new insights into the immunologic function of the zinc finger proteins that are widely distributed in various animals.-Du, X., Zhou, Y., Song, L., Wang, X., Zhang, S. Zinc finger protein 365 is a new maternal LPS-binding protein that defends zebrafish embryos against gram-negative bacterial infections.