Mass spectrometric identification of pEGFYSQRYamide: a crustacean peptide hormone possessing a vertebrate neuropeptide Y (NPY)-like carboxy-terminus

• Published in: General and Comparative Endocrinology
• Main Authors: Stemmler, Elizabeth A., Bruns, Emily A., Gardner, Noah P., Dickinson, Patsy S., Christie, Andrew E.
• Format: Text
• Language: English
• Published: 2007
• Subjects: Article; Lithodes maja
• Online Access: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1950731; http://www.ncbi.nlm.nih.gov/pubmed/17420018; https://doi.org/10.1016/j.ygcen.2007.02.025

In invertebrates, peptides possessing the carboxy (C)-terminal motif -RXRFamide have been proposed as the homologs of vertebrate neuropeptide Y (NPY). Using matrix assisted laser desorption/ionization mass spectrometry, in combination with sustained off-resonance irradiation collision-induced dissociation and chemical and enzymatic reactions, we have identified the peptide pEGFYSQRYamide from the neuroendocrine pericardial organ (PO) of the crab Pugettia producta. This peptide is likely the same as that previously reported, but misidentified, as PAFYSQRYamide in several earlier reports (e.g. Li et al. [2003] J. Neurochem. 87,642–656; Fu et al. [2005] J. Comp. Neurol. 493,607–626). The -QRYamide motif contained in pEGFYSQRYamide is identical to that present in many vertebrate members of the NPY superfamily. Mass spectrometric analysis conducted on the POs of several other decapods showed that pEGFYSQRYamide is present in three other brachyurans (Cancer borealis, Cancer irroratus and Cancer productus) as well as in one species from another decapod infraorder (Lithodes maja, an anomuran). Thus, our findings show that at least some invertebrates possess NPY-like peptides in addition to those exhibiting an -RXRFamide C-terminus, and raise the question as to whether the invertebrate -QRYamides are functionally and/or evolutionarily related to the NPY superfamily.