Molecular, mass spectral, and physiological analyses of orcokinins and orcokinin precursor-related peptides in the lobster Homarus americanus and the crayfish Procambarus clarkii

Patsy S. Dickinson, Elizabeth A. Stemmler, Elizabeth E. Barton, Christopher R. Cashman, Noah P. Gardner, Szymon Rus, Henry R. Brennan, Timothy S. McClintock, Andrew E. Christie

Research output: Contribution to journalArticlepeer-review

45 Scopus citations


Recently, cDNAs encoding prepro-orcokinins were cloned from the crayfish Procambarus clarkii; these cDNAs encode multiple copies of four orcokinin isoforms as well as several other peptides. Using the translated open reading frames of the P. clarkii transcripts as queries, five ESTs encoding American lobster Homarus americanus orthologs were identified via BLAST analysis. From these clones, three cDNAs, each encoding one of two distinct prepro-hormones, were characterized. Predicted processing of the deduced prepro-hormones would generate 13 peptides, 12 of which are conserved between the 2 precursors: the orcokinins NFDEIDRSGFGFN (3 copies), NFDEIDRSGFGFH (2 copies) and NFDEIDRSGFGFV (2 copies), FDAFTTGFGHN (an orcomyotropin-related peptide), SSEDMDRLGFGFN, GDY(SO3)DVYPE, VYGPRDIANLY and SAE. Additionally, one of two longer peptides (GPIKVRFLSAIFIPIAAPARSSPQQDAAAGYTDGAPV or APARSSPQQDAAAGYTDGAPV) is predicted from each prepro-hormone. MALDI-FTMS analyses confirmed the presence of all predicted orcokinins, the orcomyotropin-related peptide, and three precursor-related peptides, SSEDMDRLGFGFN, GDYDVYPE (unsulfated) and VYGPRDIANLY, in H. americanus neural tissues. SAE and the longer, unshared peptides were not detected. Similar complements of peptides are predicted from P. clarkii transcripts; the majority of these were detected in its neural tissues with mass spectrometry. Truncated orcokinins not predicted from any precursor were also detected in both species. Consistent with previous studies in the crayfish Orconectes limosus, NFDEIDRSGFGFN increased mid-/hindgut motility in P. clarkii. Surprisingly, the same peptide, although native to H. americanus, did not affect gut motility in this species. Together, our results provide the framework for future investigations of the regulation and physiological function of orcokinins/orcokinin precursor-related peptides in astacideans.

Original languageEnglish
Pages (from-to)297-317
Number of pages21
Issue number2
StatePublished - Feb 2009

Bibliographical note

Funding Information:
Financial support for this work was provided by National Science Foundation grants IBN-0111040 (PSD) and MRI-0116416 (EAS), NIH Grant Number P20 RR-016463 from the INBRE Program of the National Center for Research Resources (to MDIBL; Patricia Hand Ph.D., PI), the Arnold and Mabel Beckman Foundation (CRC), the Merck Foundation (CRC), a Mount Desert Island Biological Laboratory New Investigator Award through the Salisbury Cove Research Fund provided by the Thomas H. Maren Foundation (AEC), and through institutional funds provided by MDIBL (AEC).


  • Commissural ganglion
  • Expressed sequence tag (EST)
  • Homarus americanus
  • Matrix assisted laser desorption/ionization Fourier transform mass spectrometry
  • Orcokinin
  • Orcomyotropin
  • Procambarus clarkii
  • Sinus gland
  • Stomatogastric ganglion
  • Supraoesophageal ganglion
  • cDNA

ASJC Scopus subject areas

  • Biochemistry
  • Physiology
  • Endocrinology
  • Cellular and Molecular Neuroscience


Dive into the research topics of 'Molecular, mass spectral, and physiological analyses of orcokinins and orcokinin precursor-related peptides in the lobster Homarus americanus and the crayfish Procambarus clarkii'. Together they form a unique fingerprint.

Cite this