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Neuropeptidergic Signaling in the American Lobster Homarus americanus: New Insights from High-Throughput Nucleotide Sequencing.

Christie AE, Chi M, Lameyer TJ, Pascual MG, Shea DN, Stanhope ME, Schulz DJ, Dickinson PS - PLoS ONE (2015)

Bottom Line: The deduced receptor proteins are the first descriptions of H. americanus neuropeptide receptors, and include ones for most of the peptide groups mentioned earlier, as well as those for ecdysis-triggering hormone, red pigment concentrating hormone and short neuropeptide F.Multiple receptors were identified for most peptide families.These data represent the most complete description of the molecular underpinnings of peptidergic signaling in H. americanus, and will serve as a foundation for future gene-based studies of neuropeptidergic control in the lobster.

View Article: PubMed Central - PubMed

Affiliation: Békésy Laboratory of Neurobiology, Pacific Biosciences Research Center and Technology, 6500 College Station, University of Hawaii at Manoa, 1993 East-West Road, Honolulu, Hawaii, 96822, United States of America.

ABSTRACT
Peptides are the largest and most diverse class of molecules used for neurochemical communication, playing key roles in the control of essentially all aspects of physiology and behavior. The American lobster, Homarus americanus, is a crustacean of commercial and biomedical importance; lobster growth and reproduction are under neuropeptidergic control, and portions of the lobster nervous system serve as models for understanding the general principles underlying rhythmic motor behavior (including peptidergic neuromodulation). While a number of neuropeptides have been identified from H. americanus, and the effects of some have been investigated at the cellular/systems levels, little is currently known about the molecular components of neuropeptidergic signaling in the lobster. Here, a H. americanus neural transcriptome was generated and mined for sequences encoding putative peptide precursors and receptors; 35 precursor- and 41 receptor-encoding transcripts were identified. We predicted 194 distinct neuropeptides from the deduced precursor proteins, including members of the adipokinetic hormone-corazonin-like peptide, allatostatin A, allatostatin C, bursicon, CCHamide, corazonin, crustacean cardioactive peptide, crustacean hyperglycemic hormone (CHH), CHH precursor-related peptide, diuretic hormone 31, diuretic hormone 44, eclosion hormone, FLRFamide, GSEFLamide, insulin-like peptide, intocin, leucokinin, myosuppressin, neuroparsin, neuropeptide F, orcokinin, pigment dispersing hormone, proctolin, pyrokinin, SIFamide, sulfakinin and tachykinin-related peptide families. While some of the predicted peptides are known H. americanus isoforms, most are novel identifications, more than doubling the extant lobster neuropeptidome. The deduced receptor proteins are the first descriptions of H. americanus neuropeptide receptors, and include ones for most of the peptide groups mentioned earlier, as well as those for ecdysis-triggering hormone, red pigment concentrating hormone and short neuropeptide F. Multiple receptors were identified for most peptide families. These data represent the most complete description of the molecular underpinnings of peptidergic signaling in H. americanus, and will serve as a foundation for future gene-based studies of neuropeptidergic control in the lobster.

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Two examples of the in silico workflow used for the prediction of putative mature Homarus americanus peptide structures.(A) Predicted processing scheme for prepro-adipokinetic hormone-corazonin-like peptide (ACP). The structure of the mature ACP isoform is shown in red, with the structures of two mature linker/precursor-related peptides shown in blue. In this schematic, the presence of a pyroglutamic acid in the putative mature ACP isoform is indicated by “pQ”. (B) Predicted processing scheme for prepro-FLRFamide. In this schematic, the structures of nine mature FLRFamide-like peptides are shown in red, with those of nine mature linker/precursor-related peptides shown in blue. Sulfated tyrosine residues in two of the linker/precursor-related sequences are indicated by “Y(SO3H)”. The presence of a disulfide bond between the cysteine residues in another of the linker/precursor-related peptides is indicated by an inverted blue bracket.
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pone.0145964.g001: Two examples of the in silico workflow used for the prediction of putative mature Homarus americanus peptide structures.(A) Predicted processing scheme for prepro-adipokinetic hormone-corazonin-like peptide (ACP). The structure of the mature ACP isoform is shown in red, with the structures of two mature linker/precursor-related peptides shown in blue. In this schematic, the presence of a pyroglutamic acid in the putative mature ACP isoform is indicated by “pQ”. (B) Predicted processing scheme for prepro-FLRFamide. In this schematic, the structures of nine mature FLRFamide-like peptides are shown in red, with those of nine mature linker/precursor-related peptides shown in blue. Sulfated tyrosine residues in two of the linker/precursor-related sequences are indicated by “Y(SO3H)”. The presence of a disulfide bond between the cysteine residues in another of the linker/precursor-related peptides is indicated by an inverted blue bracket.

Mentions: The identification of the transcripts just described allowed for the prediction of a new neuropeptidome for H. americanus. Here, each transcript was translated (Fig 1 and S2 Fig), and the deduced protein was subjected to a well-vetted peptide prediction workflow (Fig 1). First, each deduced pre/preprohormone was assessed for its completeness, i.e., was it a full-length protein, an amino (N)-terminal partial protein, a carboxyl (C)-terminal partial protein or an internal fragment of a protein. Full-length proteins were defined by having stop codons bracketing the open reading frame (ORF) in their transcript and possessing a functional signal peptide; putative full-length proteins did not have a stop codon located before the theorized “start” methionine, but a signal sequence was predicted starting with this residue. N-terminal partial proteins possessed no stop codon at the end of their ORFs, while C-terminal partial proteins lacked a stop codon before the ORF and did not display a “start” methionine (that produced a signal peptide). Internal protein fragments possessed no stop codon prior to their ORF and there was no evident start methionine; additionally, they lacked a stop codon at the end of their transcript’s putative coding sequence. The completeness of all deduced proteins, as well as their lengths and the lengths of the transcripts that encode them, is provided in Table 1.


Neuropeptidergic Signaling in the American Lobster Homarus americanus: New Insights from High-Throughput Nucleotide Sequencing.

Christie AE, Chi M, Lameyer TJ, Pascual MG, Shea DN, Stanhope ME, Schulz DJ, Dickinson PS - PLoS ONE (2015)

Two examples of the in silico workflow used for the prediction of putative mature Homarus americanus peptide structures.(A) Predicted processing scheme for prepro-adipokinetic hormone-corazonin-like peptide (ACP). The structure of the mature ACP isoform is shown in red, with the structures of two mature linker/precursor-related peptides shown in blue. In this schematic, the presence of a pyroglutamic acid in the putative mature ACP isoform is indicated by “pQ”. (B) Predicted processing scheme for prepro-FLRFamide. In this schematic, the structures of nine mature FLRFamide-like peptides are shown in red, with those of nine mature linker/precursor-related peptides shown in blue. Sulfated tyrosine residues in two of the linker/precursor-related sequences are indicated by “Y(SO3H)”. The presence of a disulfide bond between the cysteine residues in another of the linker/precursor-related peptides is indicated by an inverted blue bracket.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4696782&req=5

pone.0145964.g001: Two examples of the in silico workflow used for the prediction of putative mature Homarus americanus peptide structures.(A) Predicted processing scheme for prepro-adipokinetic hormone-corazonin-like peptide (ACP). The structure of the mature ACP isoform is shown in red, with the structures of two mature linker/precursor-related peptides shown in blue. In this schematic, the presence of a pyroglutamic acid in the putative mature ACP isoform is indicated by “pQ”. (B) Predicted processing scheme for prepro-FLRFamide. In this schematic, the structures of nine mature FLRFamide-like peptides are shown in red, with those of nine mature linker/precursor-related peptides shown in blue. Sulfated tyrosine residues in two of the linker/precursor-related sequences are indicated by “Y(SO3H)”. The presence of a disulfide bond between the cysteine residues in another of the linker/precursor-related peptides is indicated by an inverted blue bracket.
Mentions: The identification of the transcripts just described allowed for the prediction of a new neuropeptidome for H. americanus. Here, each transcript was translated (Fig 1 and S2 Fig), and the deduced protein was subjected to a well-vetted peptide prediction workflow (Fig 1). First, each deduced pre/preprohormone was assessed for its completeness, i.e., was it a full-length protein, an amino (N)-terminal partial protein, a carboxyl (C)-terminal partial protein or an internal fragment of a protein. Full-length proteins were defined by having stop codons bracketing the open reading frame (ORF) in their transcript and possessing a functional signal peptide; putative full-length proteins did not have a stop codon located before the theorized “start” methionine, but a signal sequence was predicted starting with this residue. N-terminal partial proteins possessed no stop codon at the end of their ORFs, while C-terminal partial proteins lacked a stop codon before the ORF and did not display a “start” methionine (that produced a signal peptide). Internal protein fragments possessed no stop codon prior to their ORF and there was no evident start methionine; additionally, they lacked a stop codon at the end of their transcript’s putative coding sequence. The completeness of all deduced proteins, as well as their lengths and the lengths of the transcripts that encode them, is provided in Table 1.

Bottom Line: The deduced receptor proteins are the first descriptions of H. americanus neuropeptide receptors, and include ones for most of the peptide groups mentioned earlier, as well as those for ecdysis-triggering hormone, red pigment concentrating hormone and short neuropeptide F.Multiple receptors were identified for most peptide families.These data represent the most complete description of the molecular underpinnings of peptidergic signaling in H. americanus, and will serve as a foundation for future gene-based studies of neuropeptidergic control in the lobster.

View Article: PubMed Central - PubMed

Affiliation: Békésy Laboratory of Neurobiology, Pacific Biosciences Research Center and Technology, 6500 College Station, University of Hawaii at Manoa, 1993 East-West Road, Honolulu, Hawaii, 96822, United States of America.

ABSTRACT
Peptides are the largest and most diverse class of molecules used for neurochemical communication, playing key roles in the control of essentially all aspects of physiology and behavior. The American lobster, Homarus americanus, is a crustacean of commercial and biomedical importance; lobster growth and reproduction are under neuropeptidergic control, and portions of the lobster nervous system serve as models for understanding the general principles underlying rhythmic motor behavior (including peptidergic neuromodulation). While a number of neuropeptides have been identified from H. americanus, and the effects of some have been investigated at the cellular/systems levels, little is currently known about the molecular components of neuropeptidergic signaling in the lobster. Here, a H. americanus neural transcriptome was generated and mined for sequences encoding putative peptide precursors and receptors; 35 precursor- and 41 receptor-encoding transcripts were identified. We predicted 194 distinct neuropeptides from the deduced precursor proteins, including members of the adipokinetic hormone-corazonin-like peptide, allatostatin A, allatostatin C, bursicon, CCHamide, corazonin, crustacean cardioactive peptide, crustacean hyperglycemic hormone (CHH), CHH precursor-related peptide, diuretic hormone 31, diuretic hormone 44, eclosion hormone, FLRFamide, GSEFLamide, insulin-like peptide, intocin, leucokinin, myosuppressin, neuroparsin, neuropeptide F, orcokinin, pigment dispersing hormone, proctolin, pyrokinin, SIFamide, sulfakinin and tachykinin-related peptide families. While some of the predicted peptides are known H. americanus isoforms, most are novel identifications, more than doubling the extant lobster neuropeptidome. The deduced receptor proteins are the first descriptions of H. americanus neuropeptide receptors, and include ones for most of the peptide groups mentioned earlier, as well as those for ecdysis-triggering hormone, red pigment concentrating hormone and short neuropeptide F. Multiple receptors were identified for most peptide families. These data represent the most complete description of the molecular underpinnings of peptidergic signaling in H. americanus, and will serve as a foundation for future gene-based studies of neuropeptidergic control in the lobster.

Show MeSH