Fig. 10.

Schematic overview of several 7TM and truncated H₃ receptor isoforms. Alternative splicing in regions A (red) and/or B (orange) results in partial deletion of the N-terminal domain and/or TM2 and EL1, respectively (isoforms not shown). Distinct splice events in region C (green) results in an IL3 of variable length and/or deletion of TM5, -6, and/or -7. Alternative splicing in region D (blue) adds 8 additional residues to the C-terminal tail of H₃R. Finally, a frameshift after residue 171 results in a truncated receptor protein (magenta). Truncated H₃ receptor isoforms are indicated in gray.