Members of the short neuropeptide F (sNPF) family of peptides and their cognate receptors play key roles in a variety of physiological processes in arthropods. In silico screening of GigasDatabase, a specific expressed sequence tag database from the Pacific oyster Crassostrea gigas, resulted in the identification of a receptor (Cg-sNPFR-like) phylogenetically closely related to sNPF receptors (...

Glucose homeostasis is finely regulated by a number of hormones and peptides released mainly from the brain, gastrointestinal tract, and muscle, regulating pancreatic secretion through cellular receptors and their signal transduction cascades. The endocrine function of the pancreas is controlled by islets within the exocrine pancreatic tissue that release hormones like insulin, glucagon, somato...

The aim of this study was to determine the modulatory effects of peptide 234 (p234) (an antagonist of GPR54 receptors) on kisspeptin and RF9 (an RFamide-related peptide antagonist)-induced changes in reproductive functions and energy balance in female rats. Female Sprague-Dawley rats were weaned on postnatal day (pnd) 21. The animals were intracerebroventricularly cannulated under general anest...

Antho-RWamide I (less than Glu-Ser-Leu-Arg-Trp-NH2) and Antho-RWamide II (less than Glu-Gly-Leu-Arg-Trp-NH2), the second and third anthozoan neuropeptides to be identified, both induced slow contractions of several endodermal muscles in four species of sea anemone. In a fifth species, Protanthea simplex, Antho-RWamide II, but not Antho-RWamide I, evoked contractions of body wall muscles. Isolat...

Temperature changes influence the reaction rates of all biological processes, which can pose dramatic challenges to cold-blooded organisms, and the capability to adapt to temperature fluctuations is crucial for the survival of these animals. In order to understand the roles that neuropeptides play in the temperature stress response, we employed a mass spectrometry-based approach to investigate ...

We have analyzed in detail the neuronal network that generates heartbeat in the leech. Reciprocally inhibitory pairs of heart interneurons form oscillators that pace the heartbeat rhythm. Other heart interneurons coordinate these oscillators. These coordinating interneurons, along with the oscillators interneurons, form an eight-cell timing oscillator network for heartbeat. Still other interneu...

The Drosophila dromyosuppressin peptide (TDVDHVFLRFamide) is a member of a family of peptides containing the common C-terminal sequence -RFamide. Dromyosuppressin shares a high degree of sequence homology with leucomyosuppressin isolated from cockroach (pEDVDHVFLRFamide) and identity with neomyosuppressin isolated from fleshfly. By means of sequence-specific antisera, the cellular expression pa...

In 1977, Price and Greenberg identified the tetrapeptide FMRFamide as a cardioexcitatory molecule from mollusc. Subsequent to this discovery, FMRFamide-related peptides (FaRPs) have been identified in both invertebrates and vertebrates. Peptides in the FaRP family contain a common RFamide C-terminus and act as modulators and messengers of neural and gastrointestinal functions. Like other organi...

In the three decades since the FMRFamide peptide was isolated from the mollusk Macrocallista nimbosa, structurally similar peptides sharing a C-terminal RFamide motif have been identified across the animal kingdom. FMRFamide-like peptides (FLPs) represent the largest known family of neuropeptides in invertebrates. In the phylum Nematoda, at least 32 flp-genes are classified, making the FLP syst...