Fig. 1. Mutations in the cytoplasmic tail of FcRn. Schematic representation of the amino acid sequences of the cytoplasmic domains of wild-type and mutant rat FcRn chains used in this study. Mutated residues are in bold. The residues previously identified as components of the tryptophan-based (black) and dileucine-based (gray) basolateral-targeting signals are highlighted.