OKB, a novel family of brain-gut neuropeptides from insects

Abstract

In insects, neuropeptides play a central role in the control of most physiological processes. The knowledge and characterization of new neuropeptide families, is of interest on the fields of Genetics, Genomics, Neurobiology, Endocrinology and Evolution. This knowledge also provides the tools for the design of peptidomimetics, pseudopeptides or small molecules, capable of disrupting the physiological processes regulated by the signaling molecules and their receptors. This is a promising target for a novel generation of insecticides. Using database searches, mass spectrometry and RACE-PCR, we identified a neuropeptide precursor transcript encoding a new family of insect neuropeptides in the hemipteran Rhodnius prolixus. We named this precursor Orcokinin B, because is originated by the alternative splicing of the Orcokinin gen. EST and genomic data suggests that Orcokinin B is expressed in the nervous system and gut from several insect species, with the exception of Drosophila sp. (Diptera) and Acyirthosiphon pisum (Hemiptera). Mass spectrometry and RT-PCR confirmed the expression of Orcokinin B in brain and anterior midgut of R. prolixus. Furthermore, we identified orthologues of this new family of peptides in genomic and EST databases from Arachnids and Crustaceans.

Peptidomics of Neuropeptidergic Tissues of the Tsetse FlyGlossina morsitans morsitans

“…Orcokinin-A is involved in circadian behavior [83] and ecdysteroidogenesis [84], whereas for orcokinin-B, which has only recently been identified, no functions have been described hitherto [85]. In G. m. morsitans we could only detect orcokinin A (originating from gene GMOY009230) in both the brain and TG.…”

Identification of G protein coupled receptors for opsines and neurohormones in Rhodnius prolixus. Genomic and transcriptomic analysis

“…For neuropeptides, we used the specific sequences of R. prolixus described earlier as queries Orchard et al, 2011;Sterkel et al, 2012;Zandawala et al, 2010) and orthologues from B. mori, D. melanogaster and T. castaneum for molecules not reported in R. prolixus. For GPCRs we used the sequences predicted in this study (see 2.1) and previous reports (Paluzzi and O'Donnell, 2012;Paluzzi et al, 2014;Zandawala et al, 2013) as queries.…”

“…We performed database searches in R. prolixus nervous system and T. dimidiata, T. infestans and T. pallidipennis normalized transcriptomes using the sequences of R. prolixus neuropeptide precursor genes previously described as queries Orchard et al, 2011;Sterkel et al, 2012). Orthologous sequences 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 …”

“…Manipulations in the interaction of neuropeptides and their receptors through peptidomimetics or pseudopeptides could disrupt fundamental physiological processes. These facts motivated our comprehensive analysis of R. prolixus neuropeptide complement over the last few years (Ons et al, , 2009Sterkel et al, 2012). Since functional information regarding individual genes encoding R. prolixus GPCRs has arisen recently (Paluzzi and O'Donnell, 2012;Paluzzi et al, 2014;Zandawala et al, 2013), a genome-wide comprehensive analysis of the GPCRs of R. prolixus has not been performed.…”

DINeR — A Database for Insect Neuropeptide Research

“…Insulin-like peptides are encoded by up to 38 paralogous genes in the moth Bombyx mori and 8 genes in Drosophila (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;Sterkel et al, 2012). A typical prepropeptide and its biosynthesis and processing is shown in Fig.…”