Figure 1.—

The structure and protein sequence alignment of the PACAP precursor gene in human and other vertebrate species. The PACAP precursor contains five domains, including the signal peptide (SP), the UD, the PRP, the spacing domain (SD), and PACAP (Vaudry et al. 2000). The numbers indicate relevant amino acid residues. The shaded sites and the solid triangles refer to the fixed substitutions in humans. The arrows indicate the single or paired basic amino acids that can be cleaved by precursor convertase in post-translational processing. The question marks indicate the within-species polymorphic sites (D/G at site 54 in humans, D/H at site 82 in chimpanzees, E/D at site 40 in gorillas, P/L at site 34 in gibbons, and Y/F at site 25, P/Q at site 58, and R/T at site 81 in rhesus monkeys). HUM, human; CHP, chimpanzee; GOR, gorilla; ORA, orangutan; GIB, white-browed gibbon; RHM, rhesus monkey; MOU, mouse; SHP, sheep; CHK, chicken; XEN, Xenopus; and DAN, danio.