DINeR

A Database for Insect Neuropeptide Research

Search the database for information about the various species and neuropeptides of interest

Insect Neuropeptides

Insect neuropeptides are involved in a variety of host functions, including energy metabolism, osmoregulation and mating behavior. The study on insect neuroendocrinology has rapidly grown and there are roughly 50 identified insect neuropeptide families.

Neuropeptides are produced from larger precursor proteins which are known as prepropeptides. Prepropeptides comprise of a signal peptide (which directs the protein to the secretory pathway), progenitors of mature peptides (the biologically-active peptides), spacer peptides (peptide fragments with no known biological function and non-conserved sequences) and cleavage sites (monobasic and dibasic). Each precursor can give rise to one or more mature neuropeptides or peptide hormones. The number of mature peptides produced from a given precursor can vary from one insect species to another. These can either be (1) a set of very similar peptides with partly conserved sequences and thus similar receptor activation properties (such as tachykinin-related peptides, AstBs and FMRFamides), or (2) in some cases peptides with distinct sequences and functions. Examples of precursors containing peptides with distinct sequences and functions (bind distinct receptors) are those of CAPA/Pyrokinin, NPLP1 and vasopressin (see Stafflinger et al., 2008; Nässel and Winther 2010). There are also examples of peptides with similar sequences being produced by paralogs and splice variants. Insulin-like peptides are encoded by up to 38 paralogous genes in the moth Bombyx mori and 8 genes in Drosophila (see Mizoguchi and Okamoto, 2013). The orcokinin gene in insects produces two different neuropeptide precursors by alternative splicing: orcokinin A and orcokinin B (Jiang et al, 2015). A typical prepropeptide and its biosynthesis and processing is shown in the diagram.

All information on the neuropeptides (More Info) provided by Dr. Meet Zandawala and Prof. Dr. Dick R. Nässel from the Department of Zoology, Stockholm University, Stockholm, Sweden

Diagram showing neuropeptide prepropeptide production and processing. Neuropeptide production starts in the nucleus and ends in the dense core vesicle. Neuropeptides are produced as part of larger precursor proteins, known as prepropeptides, which are encoded in the genome. These can give rise to one or several bioactive peptides. Neuropeptide encoding genes are transcribed in the nucleus. After splicing, mRNA is translated on ribosomes and with the aid of a signal peptide the immature prepropeptide is incorporated in the secretory pathway and ends up in vesicles. As the vesicles are transported to the axon termination the precursor is processed. The bioactive peptides are each surrounded by mono- or dibasic cleavage sites such as KR or RR shown here, that direct peptidases to enzymatically liberate the peptides. The white boxes represent non-conserved sequences (spacing regions) between peptide progenitors. Finally, posttranslational modifications may occur, such as C-terminal amidation (-NH2) shown here. The mature neuropeptides are stored in dense core vesicles in the axon termination. A depolarization of the axon termination followed by Ca2+ influx triggers release of the peptide. This figure was redrawn and modified from Fig. 11.1 in Nässel and Larhammar (2013).

Below is a list of insect neuropeptide families. Where applicable, their synonyms are also listed. To find out more about each insect neuropeptide, please click on the ‘More Info’ button.
Neuropeptide Abbreviation Synonyms More Information

Jiang, H., Kim, H. G., & Park, Y., 2015. Alternatively spliced orcokinin isoforms and their functions in Tribolium castaneum. Insect Biochemistry and Molecular Biology. 65, 1–9.

Mizoguchi, A., Okamoto, N., 2013. Insulin-like and IGF-like peptides in the silkmoth Bombyx mori: discovery, structure, secretion, and function. Frontiers in Physiology. 4, 217.

Nässel, D. R., Larhammar, D (2013) Neuropeptides and peptide hormones. In: Galizia, C.G and Lledo, P.M (Eds) Neurosciences - From Molecule to Behavior: a university textbook. Springer, Berlin, pp 213-237.

Nässel, D.R., Winther, Å.M., 2010. Drosophila neuropeptides in regulation of physiology and behavior. Progress in Neurobiology. 92, 42–104.

Stafflinger, E., Hansen, K. K., Hauser, F., Schneider, M., Cazzamali, G., Williamson, M., & Grimmelikhuijzen, C. J. P., 2008. Cloning and identification of an oxytocin/vasopressin-like receptor and its ligand from insects. Proceedings of the National Academy of Sciences of the United States of America, 105(9), 3262–7.

© Dow-Davies Lab, 2018