Fig. 5. Nomenclature for Strongylocentrotus purpuratus SALMFamide neuropeptides and comparison with the sequences of other echinoderm SALMFamide neuropeptides. (A) The predicted amino acid sequence of the Strongylocentrotus purpuratus SALMFamide precursor showing the positions of putative SALMFamide neuropeptides (red), which we have named SpurS1-SpurS7 based on their relative position in the precursor. The signal peptide is shown in blue and putative monobasic and dibasic (K, KR, RR) cleavage sites are shown in green. (B). The sequences of starfish and sea cucumber SALMFamides are shown aligned with the seven putative sea urchin SALMFamides (SpurS1-SpurS7) identified in this study. Four of the putative neuropeptides in Strongylocentrotus purpuratus (SpurS1, SpurS2, SpurS3, SpurS6) have the same consensus sequence as the starfish and sea cucumber SALMFamides (i.e. SxL/FxFamide, where x is variable). SpurS4, SpurS5 and SpurS7 have a proline or leucine residue substituted for the serine residue in the consensus sequence but share the sequence FxFamide with SpurS1, SpurS2, SpurS3, SpurS6 and the Stichopus SALMFamides GYSPFMFamide and FKSPFMFamide. References: ¹Elphick et al., 1991a,b; ²Díaz-Miranda et al., 1992; ³Ohtani et al., 1999; ⁴present study.