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Andrew E Christie - One of the best experts on this subject based on the ideXlab platform.

  • molecular cloning of four cdnas encoding prepro crustacean hyperglycemic Hormone chh from the eyestalk of the red rock crab cancer productus identification of two genetically encoded chh isoforms and two putative post translationally derived chh variants
    General and Comparative Endocrinology, 2008
    Co-Authors: Yunwei A Hsu, Andrew E Christie, John R Weller, Horacio O De La Iglesia
    Abstract:

    Recently, we demonstrated that the four known sinus gland (SG) isoforms of Cancer productus crustacean hyperglycemic Hormone Precursor-related peptide (Capr-CPRP I–IV) are differentially distributed in conserved patterns among individual crabs. This finding strongly supported the presence of multiple prepro-crustacean hyperglycemic Hormone (chh) transcripts in each crab, as well as the translation and processing of the encoded prepro-Hormones. Whether these transcripts contained common or distinct isoforms of CHH remained unknown. To address this question, molecular analyses of the C. productus eyestalk prepro-chhs were undertaken. Using a PCR-based cloning strategy, four prepro-chh cDNAs were characterized: one encoding CPRP I, one encoding CPRP III (found to possess Ile26 rather than Leu26 as reported previously), and two encoding CPRP II. No cDNA encoding CPRP IV was identified. The deduced CHH present in the prepro-Hormones containing CPRP I and III were identical (Capr-CHH I) and differed from that (Capr-CHH II) present in the two prepro-Hormones containing Capr-CPRP II at a single residue, a Thr5 for Ser5 substitution. As both CHH isoforms possess Glu at position 1, a cyclization of this residue to pyroglutamine is likely as the peptides mature, as has been seen for the CHHs of other brachyuran species. Likewise, homology to other CHHs suggests all C. productus isoforms are C-terminally amidated. These post-translational modifications would result in four SG isoforms of CHH: Capr-CHH I, Capr-pyro-CHH I, Capr-CHH II, and Capr-pyro-CHH II. Southern blotting supported the hypothesis that at least three prepro-chh transcripts are present in each crab, while dual in situ hybridization-immunohistochemistry localized the transcripts to previously mapped CHH immunopositive somata in the X-organ, the major source of innervation to the SG.

  • direct tissue maldi ftms profiling of individual cancer productus sinus glands reveals that one of three distinct combinations of crustacean hyperglycemic Hormone Precursor related peptide cprp isoforms are present in individual crabs
    General and Comparative Endocrinology, 2007
    Co-Authors: Elizabeth A Stemmler, Andrew E Christie, Christopher R Cashman, Daniel I Messinger, Horacio O De La Iglesia, Patsy S Dickinson
    Abstract:

    Over the past decade, mass spectrometry has become a prominent technique for identifying peptide Hormones. In crustaceans, studies directed at characterizing the peptide complements present in neuroendocrine structures have generally involved the isolation of tissue from a large number of individuals, which are pooled, extracted, purified, and then analyzed via chromatographic techniques coupled with mass spectrometry. While this approach provides information on the peptides present in the population of animals used as the tissue source, data on the peptide complement present in any individual animal are lost. Direct tissue matrix assisted laser desorption/ionization Fourier transform mass spectrometry (MALDI-FTMS) of single tissues has the potential to identify differences in peptide expression between individuals. Here, we have used direct tissue MALDI-FTMS of individual sinus glands (SGs) to show that the four isoforms of crustacean hyperglycemic Hormone Precursor-related peptide (CPRP) identified previously from pooled Cancer productus SGs (i.e. Fu, Q., Christie, A.E., Li, L. 2005. Mass spectrometric characterization of crustacean hyperglycemic Hormone Precursor-related peptides (CPRPs) from the sinus gland of the crab, Cancer productus. Peptides 26, 2137–2150.) are differentially distributed in conserved patterns among individual crabs. Of the crabs examined, ∼61% of the individuals possessed Capr-CPRP I and II, but not III or IV, ∼26% Capr-CPRP I, II and III, but not IV, and ∼13% Capr-CPRP I, II and IV, but not III. Our findings set the stage for future molecular investigations on the origin(s) of this individual-specific variation in CPRP complement, as well as investigations of the function and regulation of the individual isoforms. These data also lend a cautionary note to the assumption that the peptides identified via pooled tissues reveal an accurate picture of the peptides present in any given individual.

  • mass spectrometric characterization of crustacean hyperglycemic Hormone Precursor related peptides cprps from the sinus gland of the crab cancer productus
    Peptides, 2005
    Co-Authors: Qiang Fu, Andrew E Christie, Lingjun Li
    Abstract:

    Abstract Crustacean hyperglycemic Hormone (CHH) Precursor-related peptides (CPRPs) are produced during the proteolytic processing of CHH preproHormones. Currently, the physiological roles played by CPRPs are unknown. Due to their large size, direct mass spectrometric sequencing of intact CPRPs is difficult. Here, we describe a novel strategy for sequencing Cancer productus CPRPs directly from a tissue extract using nanoflow liquid chromatography coupled to quadrupole time-of-flight tandem mass spectrometry. Four novel CPRPs were characterized with the aid of MS/MS de novo sequencing of 27 truncated CPRP peptides. Extensive modifications (methionine oxidation and carboxy-terminal methylation) were identified in both the full-length and truncated peptides. To investigate the origin of the modifications and truncations, a full-length CPRP was synthesized and subjected to the same storage and extraction protocols used for the characterization of the native peptides. Here, some methionine oxidation was seen, however, no methylation or truncation was evident suggesting much of the chemical complexity seen in the native CPRPs is unlikely due to a sample preparation artifact. Collectively, our study represents the most complete characterization of CPRPs to date and provides a foundation for future investigation of CPRP function in C. productus .

Peiyuan Qian - One of the best experts on this subject based on the ideXlab platform.

  • in silico prediction of neuropeptides peptide Hormone transcripts in the cheilostome bryozoan bugula neritina
    PLOS ONE, 2016
    Co-Authors: Yue Him Wong, Peiyuan Qian, Gen Zhang
    Abstract:

    The bryozoan Bugula neritina has a biphasic life cycle that consists of a planktonic larval stage and a sessile juvenile/adult stage. The transition between these two stages is crucial for the development and recruitment of B. neritina. Metamorphosis in B. neritina is mediated by both the nervous system and the release of developmental signals. However, no research has been conducted to investigate the expression of neuropeptides (NP)/peptide Hormones in B. neritina larvae. Here, we report a comprehensive study of the NP/peptide Hormones in the marine bryozoan B. neritina based on in silico identification methods. We recovered 22 transcripts encompassing 11 NP/peptide Hormone Precursor transcript sequences. The transcript sequences of the 11 isolated NP Precursors were validated by cDNA cloning using gene-specific primers. We also examined the expression of three peptide Hormone Precursor transcripts (BnFDSIG, BnILP1, BnGPB) in the coronate larvae of B. neritina, demonstrating their distinct expression patterns in the larvae. Overall, our findings serve as an important foundation for subsequent investigations of the peptidergic control of bryozoan larval behavior and settlement.

  • In Silico Prediction of Neuropeptides/Peptide Hormone Transcripts in the Cheilostome Bryozoan Bugula neritina
    PloS one, 2016
    Co-Authors: Yue Him Wong, Zhang, Peiyuan Qian
    Abstract:

    The bryozoan Bugula neritina has a biphasic life cycle that consists of a planktonic larval stage and a sessile juvenile/adult stage. The transition between these two stages is crucial for the development and recruitment of B. neritina. Metamorphosis in B. neritina is mediated by both the nervous system and the release of developmental signals. However, no research has been conducted to investigate the expression of neuropeptides (NP)/peptide Hormones in B. neritina larvae. Here, we report a comprehensive study of the NP/peptide Hormones in the marine bryozoan B. neritina based on in silico identification methods. We recovered 22 transcripts encompassing 11 NP/peptide Hormone Precursor transcript sequences. The transcript sequences of the 11 isolated NP Precursors were validated by cDNA cloning using gene-specific primers. We also examined the expression of three peptide Hormone Precursor transcripts (BnFDSIG, BnILP1, BnGPB) in the coronate larvae of B. neritina, demonstrating their distinct expression patterns in the larvae. Overall, our findings serve as an important foundation for subsequent investigations of the peptidergic control of bryozoan larval behavior and settlement.

Liliane Schoofs - One of the best experts on this subject based on the ideXlab platform.

  • aprp the second peptide encoded by the adipokinetic Hormone gene s is highly conserved in evolution a role in control of ecdysteroidogenesis
    Annals of the New York Academy of Sciences, 2009
    Co-Authors: Arnold De Loof, Tim Vandersmissen, Steven J Husson, Bart Landuyt, Jurgen Huybrechts, Marleen Lindemans, Elke Clynen, Liliane Schoofs
    Abstract:

    Since the early days of cloning the first adipokinetic Hormone (AKH) gene, researchers recognized that this gene also codes for a joining region and for a second peptide called adipokinetic Hormone Precursor related peptide (APRP). In species with more than one AKH gene, such as locusts, APRPs can form both homodimers and heterodimers. Database analysis showed that APRPs might belong to the ancient family of growth Hormone releasing factor but they still are functionally orphan. We investigated whether some of the APRP forms play a role in control of reproduction or/and growth via stimulation of ecdysteroidogenesis.

  • annotation of novel neuropeptide Precursors in the migratory locust based on transcript screening of a public est database and mass spectrometry
    BMC Genomics, 2006
    Co-Authors: Elke Clynen, Jurgen Huybrechts, Arnold De Loof, Peter Verleyen, Liliane Schoofs
    Abstract:

    For holometabolous insects there has been an explosion of proteomic and peptidomic information thanks to large genome sequencing projects. Heterometabolous insects, although comprising many important species, have been far less studied. The migratory locust Locusta migratoria, a heterometabolous insect, is one of the most infamous agricultural pests. They undergo a well-known and profound phase transition from the relatively harmless solitary form to a ferocious gregarious form. The underlying regulatory mechanisms of this phase transition are not fully understood, but it is undoubtedly that neuropeptides are involved. However, neuropeptide research in locusts is hampered by the absence of genomic information. Recently, EST (Expressed Sequence Tag) databases from Locusta migratoria were constructed. Using bioinformatical tools, we searched these EST databases specifically for neuropeptide Precursors. Based on known locust neuropeptide sequences, we confirmed the sequence of several previously identified neuropeptide Precursors (i.e. pacifastin-related peptides), which consolidated our method. In addition, we found two novel neuroparsin Precursors and annotated the hitherto unknown tachykinin Precursor. Besides one of the known tachykinin peptides, this EST contained an additional tachykinin-like sequence. Using neuropeptide Precursors from Drosophila melanogaster as a query, we succeeded in annotating the Locusta neuropeptide F, allatostatin-C and ecdysis-triggering Hormone Precursor, which until now had not been identified in locusts or in any other heterometabolous insect. For the tachykinin Precursor, the ecdysis-triggering Hormone Precursor and the allatostatin-C Precursor, translation of the predicted neuropeptides in neural tissues was confirmed with mass spectrometric techniques. In this study we describe the annotation of 6 novel neuropeptide Precursors and the neuropeptides they encode from the migratory locust, Locusta migratoria. By combining the manual annotation of neuropeptides with experimental evidence provided by mass spectrometry, we demonstrate that the genes are not only transcribed but also translated into Precursor proteins. In addition, we show which neuropeptides are cleaved from these Precursor proteins and how they are post-translationally modified.

  • new insights in adipokinetic Hormone akh Precursor processing in locusta migratoria obtained by capillary liquid chromatography tandem mass spectrometry
    Peptides, 2002
    Co-Authors: Jurgen Huybrechts, Korneel Hens, Constantine Poulos, Lucien F Harthoorn, D. J. Van Der Horst, Arnold De Loof, Elke Clynen, Liliane Schoofs
    Abstract:

    After translation, the AKH I and AKH II Precursors form three dimeric constructs prior to further processing into the respective AKHs and three dimeric Adipokinetic Hormone Precursor Related Peptides or APRPs (two homodimers and one heterodimer). By capillary liquid chromatography-tandem mass spectrometry we demonstrate that the APRPs in Locusta migratoria are further processed to form two smaller neuropeptides: DAADFADPYSFL (residue 36 to 47 of the AKH I Precursor) and YADPNADPMAFL (residue 34 to 45 of the AKH II Precursor). The peptides are designated as Adipokinetic Hormone Joining Peptide 1 (AKH-JP I) and 2 (AKH-JP II) respectively. Within the AKH I and AKH II Precursor molecules, the classic KK and RR processing sites separate the AKH-JPs from the AKH I and II respectively. At the carboxyterminus, both AKH-JP I and II are flanked by Tyr-Arg, a cleaving site not described before. Such an unusual cleavage site suggests the presence, in the corpora cardiaca, of specific convertases. The AKH-JP-II does not stimulate lipid release from the fat body nor does it stimulate glycogen phosphorylase activity, both key functions of AKH. © 2002 Elsevier Science Inc. All rights reserved.

Simon G. Webster - One of the best experts on this subject based on the ideXlab platform.

  • is crustacean hyperglycaemic Hormone Precursor related peptide a circulating neuroHormone in crabs
    Cell and Tissue Research, 2002
    Co-Authors: David C Wilcockson, Sook J Chung, Simon G. Webster
    Abstract:

    Sites of synthesis and release patterns of crustacean hyperglycaemic Hormone Precursor-related peptide (CPRP) were investigated with those of crustacean hyperglycaemic Hormone (cHH), in order to determine whether this Precursor-related peptide satisfies certain criteria necessary for its definition as a secretable, circulating Hormone. Using the edible crab, Cancer pagurus, sites of CPRP synthesis were determined by immunohistochemistry and release patterns of both peptides were determined in vivo and in vitro by radioimmunoassay of haemolymph and eyestalk superfusates. Both peptides were co-released from sinus glands (SGs) following potassium-evoked depolarization of isolated eyestalk preparations. However, stress-evoked in vivo release resulted in apparent non-stoichiometric circulating peptide profiles. This phenomenon is explained by notable differences in clearance rates of the peptides in haemolymph. In contrast to cHH, CPRP is very slowly degraded in vivo. Although CPRP is clearly a circulating peptide, whose release is concomitant with that of cHH, physiologically pertinent roles for this molecule remain to be discovered.

  • amino acid sequences of both isoforms of crustacean hyperglycemic Hormone chh and corresponding Precursor related peptide in cancer pagurus
    Regulatory Peptides, 1998
    Co-Authors: Sook J Chung, Mark C Wilkinson, Simon G. Webster
    Abstract:

    Both isoforms of the crustacean hyperglycemic Hormone (CHH) and corresponding crustacean hyperglycemic Hormone Precursor-related peptide (CPRP) derived from HPLC-purified sinus gland extracts from the edible crab Cancer pagurus were fully characterised by microsequencing and mass spectrometry. The amino acid sequences of the CHH isoforms were almost identical except that the N-terminus of the minor isoform (CHH-I), was glutamine rather than pyroglutamate in the major isoform (CHH-II). Both CHH isoforms were of similar biological activity, as tested by in vivo hyperglycemia bioassays and in vitro repression of ecdysteroid synthesis. Comparison with other published CHH and CPRP sequences show that for crabs, these peptides form a distinct group, that the presence of CHH isoforms with free and blocked N-termini seems unique to crabs. It is argued that this phenomenon reflects a slow post-translational modification in sinus gland neurosecretory terminals. This study appears to complete the entire sinus gland inventory of functionally and structurally characterised CHH-related peptides in a crab.

F Sehnal - One of the best experts on this subject based on the ideXlab platform.

  • The allatostatin gene of the cricket Gryllus bimaculatus (Ensifera, Gryllidae).
    Molecular and cellular endocrinology, 2001
    Co-Authors: M Meyering-vos, K. H. Hoffmann, J Huang, M Jindra, F Sehnal
    Abstract:

    The gene encoding allatostatins (AST) of the FGLamide family from the cricket Gryllus bimaculatus is expressed in the brain. The mRNA, which contains four polyadenylation signals, encodes a Hormone Precursor that is split into at least 14 putative Hormones. Five of them have been previously found in the cricket, six to seven others, or their close homologues, are known from other insects. Hormone AST 2 contains an internal cleavage site and may exist in a shorter version 2b. The Hormones AST 3 and 4 are identical. The cDNA sequence revealed that a single point mutation and a single deletion eliminated an additional Hormone between AST 12 and 13. The deduced Hormone Precursor is very similar to that in cockroaches, but is different from a shorter Precursor in locusts, indicating that the gene evolved very fast in the latter. Regions conserved between cockroaches and crickets include parts of the acidic spacers that separate clusters of Hormones, suggesting that these spacers may have additional functions.