Fig. 2. Human PAR N-terminal and C-terminal sequences. Residues flanking the cleavage site specify protease recognition. These are defined as unprimed (P) and primed sites (P'), respectively (i.e. P3-P2-P1/P1'-P2'-P3', where / indicates the cleavage site). Only transmembrane domain (TM) 1 and TM7 are shown. The number of N-terminal residues omitted before the cleavage site is shown in parentheses and the sequences of the tethered ligand domains are shown in yellow. The hirudin-like sequence in PAR1 and PAR3 responsible for high-affinity thrombin binding is underlined. The potential sites of PAR phosphorylation are shown in red and the PAR1 distal tyrosine-based motif important for µ2 binding is underlined. Asterisks indicate the end of the PAR sequences.