Direct Interaction between Anthrax Toxin Receptor 1 and the Actin Cytoskeleton

The protective antigen component of anthrax toxin binds the I domain of the anthrax toxin receptors. ANTXR1 and ANTXR2, in it manner akin to how integrins bind their ligands. The I domains of integrins and ANTXR1 both have high- and low-affinity conformations. and the cytosolic tails of these receptors associate with the actin cytoskeleton I-lie association of ANTXR1 with the cytoskeleton correlates with weakened binding to PA, although it mechanistic explanation for this observation is lacking. Here, we identified a segment in the cytoplasmic tail of ANTXR1 required for its association with the cytoskeleton We synthesized it 60-mer peptide based oil this segment and demonstrated a direct Interaction between the peptide and beta-actin, Indicating that in contrast to integrins, ANTXR1 does not use art adaptor to bind the cytoskeleton. This peptide orders actin filaments into arrays, demonstrating an actin bundling activity that is novel For it membrane protein.