anthrax toxin receptor 2–dependent lethal toxin killing in vivo炭疽毒素受体2-dependent致命毒素杀死体内.pdfVIP

Anthrax Toxin Receptor 2–Dependent Lethal Toxin Killing In Vivo 1,2 3 1 4 1 Heather M. Scobie , Darran J. Wigelsworth , John M. Marlett , Diane Thomas , G. Jonah A. Rainey , 3¤ 4 3 1* D. Borden Lacy , Marianne Manchester , R. John Collier , John A. T. Young 1 Infectious Disease Laboratory, The Salk Institute for Biological Studies, La Jolla, California, United States of America, 2 Cell and Molecular Biology Graduate Program, University of Wisconsin-Madison, Madison, Wisconsin, United States of America, 3 Department of Microbiology and Molecular Genetics, Harvard Medical School, Boston, Massachusetts, United States of America, 4 Department of Cell Biology, Center for Integrative Molecular Biosciences, The Scripps Research Institute, La Jolla, California, United States of America Anthrax toxin receptors 1 and 2 (ANTXR1 and ANTXR2) have a related integrin-like inserted (I) domain which interacts with a metal cation that is coordinated by residue D683 of the protective antigen (PA) subunit of anthrax toxin. The receptor-bound metal ion and PA residue D683 are critical for ANTXR1-PA binding. Since PA can bind to ANTXR2 with reduced affinity in the absence of metal ions, we reasoned that D683 mutant forms of PA might specifically interact with ANTXR2. We show here that this is the case. The differential ability of ANTXR1 and ANTXR2 to bind D683 mutant PA proteins was mapped to nonconserved receptor residues at the binding interface with PA domain 2. Moreover, a D683K mutant form of PA that bound specifically to human and rat ANTXR2 mediated killing of rats by anthrax lethal toxin, providing strong evidence for the physiological importance of ANTXR2 in anthrax disease pathogenesis.