1
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Zhu T, Zhang X, Li R, Wu B. Efficient production of peptidylglycine α-hydroxylating monooxygenase in yeast for protein C-terminal functionalization. Int J Biol Macromol 2024; 263:130443. [PMID: 38417749 DOI: 10.1016/j.ijbiomac.2024.130443] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Revised: 02/22/2024] [Accepted: 02/23/2024] [Indexed: 03/01/2024]
Abstract
Peptidylglycine α-hydroxylating monooxygenase (PHM) is pivotal for C-terminal amidation of bioactive peptides in animals, offering substantial potential for customized protein synthesis. However, efficient PHM production has been hindered by the complexity of animal cell culture and the absence of glycosylation in bacterial hosts. Here, we demonstrate the recombinant expression of Caenorhabditis elegans PHM in the yeast Pichia pastoris, achieving a remarkable space-time yield of 28.8 U/L/day. This breakthrough surpasses prior PHM production rates and eliminates the need for specialized cultivation equipment or complex transfection steps. Mass spectrometry revealed N-glycosylation at residue N182 of recombinant CePHM, which impacts the enzyme's activity as indicated by biochemical experiments. To showcase the utility of CePHM, we performed C-terminal amidation on ubiquitin at a substrate loading of 30 g/L, a concentration meeting the requirements for pharmaceutical peptide production. Overall, this work establishes an efficient PHM production method, promising advancements in scalable manufacturing of C-terminally modified bioactive peptides and probe proteins.
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Affiliation(s)
- Tong Zhu
- AIM center, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Xuanshuo Zhang
- AIM center, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ruifeng Li
- AIM center, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.
| | - Bian Wu
- AIM center, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.
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2
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Lee GG, Zeng K, Duffy CM, Sriharsha Y, Yoo S, Park JH. In vivo characterization of the maturation steps of a pigment dispersing factor neuropeptide precursor in the Drosophila circadian pacemaker neurons. Genetics 2023; 225:iyad118. [PMID: 37364299 PMCID: PMC10471210 DOI: 10.1093/genetics/iyad118] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 05/19/2023] [Accepted: 06/13/2023] [Indexed: 06/28/2023] Open
Abstract
Pigment dispersing factor (PDF) is a key signaling molecule coordinating the neuronal network associated with the circadian rhythms in Drosophila. The precursor (proPDF) of the mature PDF (mPDF) consists of 2 motifs, a larger PDF-associated peptide (PAP) and PDF. Through cleavage and amidation, the proPDF is predicted to produce cleaved-PAP (cPAP) and mPDF. To delve into the in vivo mechanisms underlying proPDF maturation, we generated various mutations that eliminate putative processing sites and then analyzed the effect of each mutation on the production of cPAP and mPDF by 4 different antibodies in both ectopic and endogenous conditions. We also assessed the knockdown effects of processing enzymes on the proPDF maturation. At the functional level, circadian phenotypes were measured for all mutants and knockdown lines. As results, we confirm the roles of key enzymes and their target residues: Amontillado (Amon) for the cleavage at the consensus dibasic KR site, Silver (Svr) for the removal of C-terminal basic residues from the intermediates, PAP-KR and PDF-GK, derived from proPDF, and PHM (peptidylglycine-α-hydroxylating monooxygenase) for the amidation of PDF. Our results suggest that the C-terminal amidation occurs independently of proPDF cleavage. Moreover, the PAP domain is important for the proPDF trafficking into the secretory vesicles and a close association between cPAP and mPDF following cleavage seems required for their stability within the vesicles. These studies highlight the biological significance of individual processing steps and the roles of the PAP for the stability and function of mPDF which is essential for the circadian clockworks.
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Affiliation(s)
- Gyunghee G Lee
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - Kevin Zeng
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - Cole M Duffy
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - Yadali Sriharsha
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - Siuk Yoo
- Department of Life Sciences, Yeungnam University, Gyeongsan, Gyeongbuk 38541, Korea
| | - Jae H Park
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
- Genome Science and Technology Graduate Program, University of Tennessee, Knoxville, TN 37996, USA
- NeuroNET Research Center, University of Tennessee, Knoxville, TN 37996, USA
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3
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Ilina Y, Kaufmann P, Melander O, Press M, Thuene K, Bergmann A. Immunoassay-based quantification of full-length peptidylglycine alpha-amidating monooxygenase in human plasma. Sci Rep 2023; 13:10827. [PMID: 37402878 DOI: 10.1038/s41598-023-37976-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Accepted: 06/30/2023] [Indexed: 07/06/2023] Open
Abstract
A one-step sandwich chemiluminescence immunometric assay (LIA) was developed for the quantification of bifunctional peptidylglycine-α-amidating monooxygenase (PAM) in human plasma (PAM-LIA). PAM is responsible for the activation of more than half of known peptide hormones through C-terminal α-amidation. The assay employed antibodies targeting specific catalytic PAM-subunits, peptidylglycine alpha-hydroxylating monooxygenase (PHM) and peptidyl-alpha-hydroxyglycine alpha-amidating lyase (PAL), to ensure detection of full-length PAM. The PAM-LIA assay was calibrated with a human recombinant PAM enzyme and achieved a detection limit of 189 pg/mL and a quantification limit of 250 pg/mL. The assay demonstrated good inter-assay (6.7%) and intra-assay (2.2%) variabilities. It exhibited linearity when accessed by gradual dilution or random mixing of plasma samples. The accuracy of the PAM-LIA was determined to be 94.7% through spiking recovery experiments, and the signal recovery after substance interference was 94-96%. The analyte showed 96% stability after six freeze-thaw cycles. The assay showed strong correlation with matched EDTA and serum samples, as well as matched EDTA and Li-Heparin samples. Additionally, a high correlation was observed between α-amidating activity and PAM-LIA. Finally, the PAM-LIA assay was successfully applied to a sub-cohort of a Swedish population-based study, comprising 4850 individuals, confirming its suitability for routine high throughput screening.
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Affiliation(s)
- Yulia Ilina
- PAM Theragnostics GmbH, Neuendorfstr. 15A, 16761, Hennigsdorf, Germany.
| | - Paul Kaufmann
- PAM Theragnostics GmbH, Neuendorfstr. 15A, 16761, Hennigsdorf, Germany
| | - Olle Melander
- Department of Clinical Sciences Malmö, Lund University, 205 02, Malmö, Sweden
- Department of Emergency and Internal Medicine, Skåne University Hospital, Malmö, Sweden
| | - Michaela Press
- PAM Theragnostics GmbH, Neuendorfstr. 15A, 16761, Hennigsdorf, Germany
| | - Katrin Thuene
- PAM Theragnostics GmbH, Neuendorfstr. 15A, 16761, Hennigsdorf, Germany
| | - Andreas Bergmann
- PAM Theragnostics GmbH, Neuendorfstr. 15A, 16761, Hennigsdorf, Germany
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4
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Glendinning S, Fitzgibbon QP, Smith GG, Ventura T. Unravelling the neuropeptidome of the ornate spiny lobster Panulirus ornatus: A focus on peptide hormones and their processing enzymes expressed in the reproductive tissues. Gen Comp Endocrinol 2023; 332:114183. [PMID: 36471526 DOI: 10.1016/j.ygcen.2022.114183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 11/21/2022] [Accepted: 11/24/2022] [Indexed: 11/29/2022]
Abstract
Neuropeptides are commonly produced in the neural tissues yet can have effects on far-reaching targets, with varied biological responses. We describe here the neuropeptidome of the ornate spiny lobster, Panulirus ornatus, a species of emerging importance to closed-system aquaculture, with a focus on peptide hormones produced by the reproductive tissues. Transcripts for a precursor to one neuropeptide, adipokinetic hormone/corazonin-related peptide (ACP) were identified in high numbers in the sperm duct of adult spiny lobsters suggesting a role for ACP in the reproduction of this species. Neuropeptide production in the sperm duct may be linked with physiological control of spermatophore production in the male, or alternatively may function in signalling to the female. The enzymes which process nascent neuropeptide precursors into their mature, active forms have seldom been studied in decapods, and never before at the multi-tissue level. We have identified transcripts for multiple members of the proprotein convertase subtisilin/kexin family in the ornate spiny lobster, with some enzymes showing specificity to certain tissues. In addition, other enzyme transcripts involved with neuropeptide processing are identified along with their tissue and life stage expression patterns.
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Affiliation(s)
- Susan Glendinning
- Centre for Bioinnovation, University of the Sunshine Coast, Maroochydore, QLD, Australia; School of Science and Engineering, University of the Sunshine Coast, Maroochydore, QLD, Australia.
| | - Quinn P Fitzgibbon
- Institute for Marine and Antarctic Studies (IMAS), University of Tasmania, Private Bag 49, Hobart, Tasmania 7001, Australia
| | - Gregory G Smith
- Institute for Marine and Antarctic Studies (IMAS), University of Tasmania, Private Bag 49, Hobart, Tasmania 7001, Australia
| | - Tomer Ventura
- Centre for Bioinnovation, University of the Sunshine Coast, Maroochydore, QLD, Australia; School of Science and Engineering, University of the Sunshine Coast, Maroochydore, QLD, Australia
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5
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Corrales M, Cocanougher BT, Kohn AB, Wittenbach JD, Long XS, Lemire A, Cardona A, Singer RH, Moroz LL, Zlatic M. A single-cell transcriptomic atlas of complete insect nervous systems across multiple life stages. Neural Dev 2022; 17:8. [PMID: 36002881 PMCID: PMC9404646 DOI: 10.1186/s13064-022-00164-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 07/10/2022] [Indexed: 12/15/2022] Open
Abstract
Molecular profiles of neurons influence neural development and function but bridging the gap between genes, circuits, and behavior has been very difficult. Here we used single cell RNAseq to generate a complete gene expression atlas of the Drosophila larval central nervous system composed of 131,077 single cells across three developmental stages (1 h, 24 h and 48 h after hatching). We identify 67 distinct cell clusters based on the patterns of gene expression. These include 31 functional mature larval neuron clusters, 1 ring gland cluster, 8 glial clusters, 6 neural precursor clusters, and 13 developing immature adult neuron clusters. Some clusters are present across all stages of larval development, while others are stage specific (such as developing adult neurons). We identify genes that are differentially expressed in each cluster, as well as genes that are differentially expressed at distinct stages of larval life. These differentially expressed genes provide promising candidates for regulating the function of specific neuronal and glial types in the larval nervous system, or the specification and differentiation of adult neurons. The cell transcriptome Atlas of the Drosophila larval nervous system is a valuable resource for developmental biology and systems neuroscience and provides a basis for elucidating how genes regulate neural development and function.
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Affiliation(s)
- Marc Corrales
- Howard Hughes Medical Institute Janelia Research Campus, Ashburn, VA, USA.,Department of Physiology, Development, and Neuroscience, Cambridge University, Cambridge, UK
| | - Benjamin T Cocanougher
- Howard Hughes Medical Institute Janelia Research Campus, Ashburn, VA, USA.,Department of Zoology, Cambridge University, Cambridge, UK
| | - Andrea B Kohn
- Department of Neuroscience and Whitney Laboratory for Marine Biosciences, University of Florida, Gainesville/St. Augustine, FL, 32080, USA
| | - Jason D Wittenbach
- Howard Hughes Medical Institute Janelia Research Campus, Ashburn, VA, USA
| | - Xi S Long
- Howard Hughes Medical Institute Janelia Research Campus, Ashburn, VA, USA
| | - Andrew Lemire
- Howard Hughes Medical Institute Janelia Research Campus, Ashburn, VA, USA
| | - Albert Cardona
- Howard Hughes Medical Institute Janelia Research Campus, Ashburn, VA, USA.,Department of Physiology, Development, and Neuroscience, Cambridge University, Cambridge, UK.,MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge, UK
| | - Robert H Singer
- Howard Hughes Medical Institute Janelia Research Campus, Ashburn, VA, USA.,Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Leonid L Moroz
- Department of Neuroscience and Whitney Laboratory for Marine Biosciences, University of Florida, Gainesville/St. Augustine, FL, 32080, USA.
| | - Marta Zlatic
- Howard Hughes Medical Institute Janelia Research Campus, Ashburn, VA, USA. .,Department of Zoology, Cambridge University, Cambridge, UK. .,MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge, UK.
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6
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Merkler DJ, Hawley AJ, Eipper BA, Mains RE. Peptidylglycine α-amidating monooxygenase as a therapeutic target or biomarker for human diseases. Br J Pharmacol 2022; 179:3306-3324. [PMID: 35124797 PMCID: PMC9177522 DOI: 10.1111/bph.15815] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 01/10/2022] [Accepted: 01/12/2022] [Indexed: 01/20/2024] Open
Abstract
Peptides play a key role in controlling many physiological and neurobiological pathways. Many bioactive peptides require a C-terminal α-amide for full activity. The bifunctional enzyme catalysing α-amidation, peptidylglycine α-amidating monooxygenase (PAM), is the sole enzyme responsible for amidated peptide biosynthesis, from Chlamydomonas reinhardtii to Homo sapiens. Many neuronal and endocrine functions are dependent upon amidated peptides; additional amidated peptides are growth promoters in tumours. The amidation reaction occurs in two steps, glycine α-hydroxylation followed by dealkylation to generate the α-amide product. Currently, most potentially useful inhibitors target the first reaction, which is rate-limiting. PAM is a membrane-bound enzyme that visits the cell surface during peptide secretion. PAM is then used again in the biosynthetic pathway, meaning that cell-impermeable inhibitors or inactivators could have therapeutic value for the treatment of cancer or psychiatric abnormalities. To date, inhibitor design has not fully exploited the structures and mechanistic details of PAM.
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Affiliation(s)
- David J Merkler
- Department of Chemistry, University of South Florida, 4202 E. Fowler Ave., Tampa, FL 33620, USA
| | - Aidan J Hawley
- Department of Chemistry, University of South Florida, 4202 E. Fowler Ave., Tampa, FL 33620, USA
| | - Betty A Eipper
- Department of Molecular Biology & Biophysics, University of Connecticut Health Center, 263 Farmington Avenue, Farmington, CT, 06030 USA
- Department of Neuroscience, University of Connecticut Health Center, 263 Farmington Avenue, Farmington, CT, 06030 USA
| | - Richard E Mains
- Department of Neuroscience, University of Connecticut Health Center, 263 Farmington Avenue, Farmington, CT, 06030 USA
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7
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Martin-Martin I, Valenzuela Leon PC, Amo L, Shrivastava G, Iniguez E, Aryan A, Brooks S, Kojin BB, Williams AE, Bolland S, Ackerman H, Adelman ZN, Calvo E. Aedes aegypti sialokinin facilitates mosquito blood feeding and modulates host immunity and vascular biology. Cell Rep 2022; 39:110648. [PMID: 35417706 PMCID: PMC9082008 DOI: 10.1016/j.celrep.2022.110648] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 02/01/2022] [Accepted: 03/17/2022] [Indexed: 11/28/2022] Open
Abstract
Saliva from mosquitoes contains vasodilators that antagonize vasoconstrictors produced at the bite site. Sialokinin is a vasodilator present in the saliva of Aedes aegypti. Here, we investigate its function and describe its mechanism of action during blood feeding. Sialokinin induces nitric oxide release similar to substance P. Sialokinin-KO mosquitoes produce lower blood perfusion than parental mosquitoes at the bite site during probing and have significantly longer probing times, which result in lower blood feeding success. In contrast, there is no difference in feeding between KO and parental mosquitoes when using artificial membrane feeders or mice that are treated with a substance P receptor antagonist, confirming that sialokinin interferes with host hemostasis via NK1R signaling. While sialokinin-KO saliva does not affect virus infection in vitro, it stimulates macrophages and inhibits leukocyte recruitment in vivo. This work highlights the biological functionality of salivary proteins in blood feeding.
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Affiliation(s)
- Ines Martin-Martin
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA.
| | - Paola Carolina Valenzuela Leon
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA
| | - Laura Amo
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA
| | - Gaurav Shrivastava
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA
| | - Eva Iniguez
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA
| | - Azadeh Aryan
- Department of Entomology and Fralin Life Science Institute, Virginia Polytechnic Institute and State University, Blacksburg, VA 24060, USA
| | - Steven Brooks
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA
| | - Bianca B Kojin
- Department of Entomology, Texas A&M University, College Station, TX 77843, USA
| | - Adeline E Williams
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA; Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins 80523, CO, USA
| | - Silvia Bolland
- Department of Entomology and Fralin Life Science Institute, Virginia Polytechnic Institute and State University, Blacksburg, VA 24060, USA
| | - Hans Ackerman
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA
| | - Zach N Adelman
- Department of Entomology and Fralin Life Science Institute, Virginia Polytechnic Institute and State University, Blacksburg, VA 24060, USA; Department of Entomology, Texas A&M University, College Station, TX 77843, USA
| | - Eric Calvo
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA.
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8
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Chen L, Kashina A. Post-translational Modifications of the Protein Termini. Front Cell Dev Biol 2021; 9:719590. [PMID: 34395449 PMCID: PMC8358657 DOI: 10.3389/fcell.2021.719590] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 06/30/2021] [Indexed: 12/12/2022] Open
Abstract
Post-translational modifications (PTM) involve enzyme-mediated covalent addition of functional groups to proteins during or after synthesis. These modifications greatly increase biological complexity and are responsible for orders of magnitude change between the variety of proteins encoded in the genome and the variety of their biological functions. Many of these modifications occur at the protein termini, which contain reactive amino- and carboxy-groups of the polypeptide chain and often are pre-primed through the actions of cellular machinery to expose highly reactive residues. Such modifications have been known for decades, but only a few of them have been functionally characterized. The vast majority of eukaryotic proteins are N- and C-terminally modified by acetylation, arginylation, tyrosination, lipidation, and many others. Post-translational modifications of the protein termini have been linked to different normal and disease-related processes and constitute a rapidly emerging area of biological regulation. Here we highlight recent progress in our understanding of post-translational modifications of the protein termini and outline the role that these modifications play in vivo.
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Affiliation(s)
| | - Anna Kashina
- Department of Biomedical Sciences, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, United States
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9
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Delgado-Prudencio G, Possani LD, Becerril B, Ortiz E. The Dual α-Amidation System in Scorpion Venom Glands. Toxins (Basel) 2019; 11:toxins11070425. [PMID: 31330798 PMCID: PMC6669573 DOI: 10.3390/toxins11070425] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 07/18/2019] [Accepted: 07/18/2019] [Indexed: 12/14/2022] Open
Abstract
Many peptides in scorpion venoms are amidated at their C-termini. This post-translational modification is paramount for the correct biological function of ion channel toxins and antimicrobial peptides, among others. The discovery of canonical amidation sequences in transcriptome-derived scorpion proproteins suggests that a conserved enzymatic α-amidation system must be responsible for this modification of scorpion peptides. A transcriptomic approach was employed to identify sequences putatively encoding enzymes of the α-amidation pathway. A dual enzymatic α-amidation system was found, consisting of the membrane-anchored, bifunctional, peptidylglycine α-amidating monooxygenase (PAM) and its paralogs, soluble monofunctional peptidylglycine α-hydroxylating monooxygenase (PHMm) and peptidyl-α-hydroxyglycine α-amidating lyase (PALm). Independent genes encode these three enzymes. Amino acid residues responsible for ion coordination and enzymatic activity are conserved in these sequences, suggesting that the enzymes are functional. Potential endoproteolytic recognition sites for proprotein convertases in the PAM sequence indicate that PAM-derived soluble isoforms may also be expressed. Sequences potentially encoding proprotein convertases (PC1 and PC2), carboxypeptidase E (CPE), and other enzymes of the α-amidation pathway, were also found, confirming the presence of this pathway in scorpions.
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Affiliation(s)
- Gustavo Delgado-Prudencio
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Avenida Universidad 2001, Colonia Chamilpa, Cuernavaca, Morelos 62210, Mexico
| | - Lourival D Possani
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Avenida Universidad 2001, Colonia Chamilpa, Cuernavaca, Morelos 62210, Mexico
| | - Baltazar Becerril
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Avenida Universidad 2001, Colonia Chamilpa, Cuernavaca, Morelos 62210, Mexico
| | - Ernesto Ortiz
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Avenida Universidad 2001, Colonia Chamilpa, Cuernavaca, Morelos 62210, Mexico.
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10
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Mueller GP, Lazarus RC, Driscoll WJ. α-Amidated Peptides: Approaches for Analysis. Methods Mol Biol 2019; 1934:247-264. [PMID: 31256384 DOI: 10.1007/978-1-4939-9055-9_16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
α-Amidation is a terminal modification in peptide biosynthesis that can itself be rate limiting in the overall production of bioactive α-amidated peptides. More than half of the known neural and endocrine peptides are α-amidated and in most cases this structural feature is essential for receptor recognition, signal transduction, and thus biologic function. This chapter describes methods for developing and using analytical tools to study the biology of α-amidated peptides. The principal analytical method used to quantify α-amidated peptides is the radioimmunoassay (RIA). Detailed protocols are provided for (1) primary antibody production and characterization; (2) radiolabeling of RIA peptides; (3) sample preparation; and (4) performance of the RIA itself. Techniques are also described for the identification and verification of α-amidated peptides. Lastly, in vivo models used for studying the biology of α-amidation are discussed.
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Affiliation(s)
- Gregory P Mueller
- Department of Anatomy, Physiology and Genetics, F. Edward Hebert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, USA.
| | - Rachel C Lazarus
- Department of Anatomy, Physiology and Genetics, F. Edward Hebert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | - William J Driscoll
- Department of Anatomy, Physiology and Genetics, F. Edward Hebert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
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11
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Christie AE, Stanhope ME, Gandler HI, Lameyer TJ, Pascual MG, Shea DN, Yu A, Dickinson PS, Hull JJ. Molecular characterization of putative neuropeptide, amine, diffusible gas and small molecule transmitter biosynthetic enzymes in the eyestalk ganglia of the American lobster, Homarus americanus. INVERTEBRATE NEUROSCIENCE 2018; 18:12. [PMID: 30276482 DOI: 10.1007/s10158-018-0216-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Accepted: 09/21/2018] [Indexed: 02/03/2023]
Abstract
The American lobster, Homarus americanus, is a model for investigating the neuromodulatory control of physiology and behavior. Prior studies have shown that multiple classes of chemicals serve as locally released/circulating neuromodulators/neurotransmitters in this species. Interestingly, while many neuroactive compounds are known from Homarus, little work has focused on identifying/characterizing the enzymes responsible for their biosynthesis, despite the fact that these enzymes are key components for regulating neuromodulation/neurotransmission. Here, an eyestalk ganglia-specific transcriptome was mined for transcripts encoding enzymes involved in neuropeptide, amine, diffusible gas and small molecule transmitter biosynthesis. Using known Drosophila melanogaster proteins as templates, transcripts encoding putative Homarus homologs of peptide precursor processing (signal peptide peptidase, prohormone processing protease and carboxypeptidase) and immature peptide modifying (glutaminyl cyclase, tyrosylprotein sulfotransferase, protein disulfide isomerase, peptidylglycine-α-hydroxylating monooxygenase and peptidyl-α-hydroxyglycine-α-amidating lyase) enzymes were identified in the eyestalk assembly. Similarly, transcripts encoding full complements of the enzymes responsible for dopamine [tryptophan-phenylalanine hydroxylase (TPH), tyrosine hydroxylase and DOPA decarboxylase (DDC)], octopamine (TPH, tyrosine decarboxylase and tyramine β-hydroxylase), serotonin (TPH or tryptophan hydroxylase and DDC) and histamine (histidine decarboxylase) biosynthesis were identified from the eyestalk ganglia, as were those responsible for the generation of the gases nitric oxide (nitric oxide synthase) and carbon monoxide (heme oxygenase), and the small molecule transmitters acetylcholine (choline acetyltransferase), glutamate (glutaminase) and GABA (glutamic acid decarboxylase). The presence and identity of the transcriptome-derived transcripts were confirmed using RT-PCR. The data presented here provide a foundation for future gene-based studies of neuromodulatory control at the level of neurotransmitter/modulator biosynthesis in Homarus.
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Affiliation(s)
- Andrew E Christie
- Békésy Laboratory of Neurobiology, Pacific Biosciences Research Center, School of Ocean and Earth Science and Technology, University of Hawaii at Manoa, 1993 East-West Road, Honolulu, HI, 96822, USA.
| | - Meredith E Stanhope
- Department of Biology, Bowdoin College, 6500 College Station, Brunswick, ME, 04011, USA
| | - Helen I Gandler
- Department of Biology, Bowdoin College, 6500 College Station, Brunswick, ME, 04011, USA
| | - Tess J Lameyer
- Department of Biology, Bowdoin College, 6500 College Station, Brunswick, ME, 04011, USA
| | - Micah G Pascual
- Békésy Laboratory of Neurobiology, Pacific Biosciences Research Center, School of Ocean and Earth Science and Technology, University of Hawaii at Manoa, 1993 East-West Road, Honolulu, HI, 96822, USA
| | - Devlin N Shea
- Department of Biology, Bowdoin College, 6500 College Station, Brunswick, ME, 04011, USA
| | - Andy Yu
- Békésy Laboratory of Neurobiology, Pacific Biosciences Research Center, School of Ocean and Earth Science and Technology, University of Hawaii at Manoa, 1993 East-West Road, Honolulu, HI, 96822, USA
| | - Patsy S Dickinson
- Department of Biology, Bowdoin College, 6500 College Station, Brunswick, ME, 04011, USA
| | - J Joe Hull
- Pest Management and Biocontrol Research Unit, US Arid Land Agricultural Research Center, USDA Agricultural Research Services, Maricopa, AZ, 85138, USA
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12
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Pei J, Kinch LN, Grishin NV. FlyXCDB—A Resource for Drosophila Cell Surface and Secreted Proteins and Their Extracellular Domains. J Mol Biol 2018; 430:3353-3411. [DOI: 10.1016/j.jmb.2018.06.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2018] [Revised: 05/31/2018] [Accepted: 06/02/2018] [Indexed: 02/06/2023]
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13
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Croset V, Treiber CD, Waddell S. Cellular diversity in the Drosophila midbrain revealed by single-cell transcriptomics. eLife 2018; 7:34550. [PMID: 29671739 PMCID: PMC5927767 DOI: 10.7554/elife.34550] [Citation(s) in RCA: 178] [Impact Index Per Article: 29.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Accepted: 04/18/2018] [Indexed: 12/12/2022] Open
Abstract
To understand the brain, molecular details need to be overlaid onto neural wiring diagrams so that synaptic mode, neuromodulation and critical signaling operations can be considered. Single-cell transcriptomics provide a unique opportunity to collect this information. Here we present an initial analysis of thousands of individual cells from Drosophila midbrain, that were acquired using Drop-Seq. A number of approaches permitted the assignment of transcriptional profiles to several major brain regions and cell-types. Expression of biosynthetic enzymes and reuptake mechanisms allows all the neurons to be typed according to the neurotransmitter or neuromodulator that they produce and presumably release. Some neuropeptides are preferentially co-expressed in neurons using a particular fast-acting transmitter, or monoamine. Neuromodulatory and neurotransmitter receptor subunit expression illustrates the potential of these molecules in generating complexity in neural circuit function. This cell atlas dataset provides an important resource to link molecular operations to brain regions and complex neural processes.
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Affiliation(s)
- Vincent Croset
- Centre for Neural Circuits and Behaviour, The University of Oxford, Oxford, United Kingdom
| | - Christoph D Treiber
- Centre for Neural Circuits and Behaviour, The University of Oxford, Oxford, United Kingdom
| | - Scott Waddell
- Centre for Neural Circuits and Behaviour, The University of Oxford, Oxford, United Kingdom
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14
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Van Bael S, Watteyne J, Boonen K, De Haes W, Menschaert G, Ringstad N, Horvitz HR, Schoofs L, Husson SJ, Temmerman L. Mass spectrometric evidence for neuropeptide-amidating enzymes in Caenorhabditis elegans. J Biol Chem 2018; 293:6052-6063. [PMID: 29487130 DOI: 10.1074/jbc.ra117.000731] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Revised: 02/18/2018] [Indexed: 12/18/2022] Open
Abstract
Neuropeptides constitute a vast and functionally diverse family of neurochemical signaling molecules and are widely involved in the regulation of various physiological processes. The nematode Caenorhabditis elegans is well-suited for the study of neuropeptide biochemistry and function, as neuropeptide biosynthesis enzymes are not essential for C. elegans viability. This permits the study of neuropeptide biosynthesis in mutants lacking certain neuropeptide-processing enzymes. Mass spectrometry has been used to study the effects of proprotein convertase and carboxypeptidase mutations on proteolytic processing of neuropeptide precursors and on the peptidome in C. elegans However, the enzymes required for the last step in the production of many bioactive peptides, the carboxyl-terminal amidation reaction, have not been characterized in this manner. Here, we describe three genes that encode homologs of neuropeptide amidation enzymes in C. elegans and used tandem LC-MS to compare neuropeptides in WT animals with those in newly generated mutants for these putative amidation enzymes. We report that mutants lacking both a functional peptidylglycine α-hydroxylating monooxygenase and a peptidylglycine α-amidating monooxygenase had a severely altered neuropeptide profile and also a decreased number of offspring. Interestingly, single mutants of the amidation enzymes still expressed some fully processed amidated neuropeptides, indicating the existence of a redundant amidation mechanism in C. elegans All MS data are available via ProteomeXchange with the identifier PXD008942. In summary, the key steps in neuropeptide processing in C. elegans seem to be executed by redundant enzymes, and loss of these enzymes severely affects brood size, supporting the need of amidated peptides for C. elegans reproduction.
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Affiliation(s)
- Sven Van Bael
- From the Department of Biology, KU Leuven (University of Leuven), Naamsestraat 59, B-3000 Leuven, Belgium,
| | - Jan Watteyne
- From the Department of Biology, KU Leuven (University of Leuven), Naamsestraat 59, B-3000 Leuven, Belgium
| | - Kurt Boonen
- From the Department of Biology, KU Leuven (University of Leuven), Naamsestraat 59, B-3000 Leuven, Belgium
| | - Wouter De Haes
- From the Department of Biology, KU Leuven (University of Leuven), Naamsestraat 59, B-3000 Leuven, Belgium
| | - Gerben Menschaert
- the Laboratory of Bioinformatics and Computational Genomics (BioBix), Department of Mathematical Modelling, Ghent University, B-9000 Ghent, Belgium
| | - Niels Ringstad
- The Helen L. and Martin S. Kimmel Center for Biology and Medicine at the Skirball Institute of Biomolecular Medicine, Department of Cell Biology, NYU Langone Medical Center, New York, New York 10016
| | - H Robert Horvitz
- the Howard Hughes Medical Institute, Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, and
| | - Liliane Schoofs
- From the Department of Biology, KU Leuven (University of Leuven), Naamsestraat 59, B-3000 Leuven, Belgium
| | - Steven J Husson
- SPHERE-Systemic Physiological and Ecotoxicological Research, Department of Biology, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium
| | - Liesbet Temmerman
- From the Department of Biology, KU Leuven (University of Leuven), Naamsestraat 59, B-3000 Leuven, Belgium,
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15
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PrAS: Prediction of amidation sites using multiple feature extraction. Comput Biol Chem 2017; 66:57-62. [DOI: 10.1016/j.compbiolchem.2016.11.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2016] [Revised: 11/27/2016] [Accepted: 11/28/2016] [Indexed: 11/22/2022]
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16
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Van Camp KA, Baggerman G, Blust R, Husson SJ. Peptidomics of the zebrafish Danio rerio : In search for neuropeptides. J Proteomics 2017; 150:290-296. [DOI: 10.1016/j.jprot.2016.09.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Revised: 09/07/2016] [Accepted: 09/27/2016] [Indexed: 12/27/2022]
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17
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McIntyre NR, Lowe EW, Battistini MR, Leahy JW, Merkler DJ. Inactivation of peptidylglycine α-hydroxylating monooxygenase by cinnamic acid analogs. J Enzyme Inhib Med Chem 2016; 31:551-62. [DOI: 10.3109/14756366.2015.1046064] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Neil R. McIntyre
- Department of Chemistry, Xavier University of Louisiana, New Orleans, LA, USA,
| | - Edward W. Lowe
- Department of Chemistry, Xavier University of Louisiana, New Orleans, LA, USA,
| | | | - James W. Leahy
- Department of Chemistry, University of South Florida, Tampa, FL, USA, and
- Florida Center for Drug Discovery and Innovation, Tampa, FL, USA
| | - David J. Merkler
- Department of Chemistry, University of South Florida, Tampa, FL, USA, and
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18
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Kumar D, Mains RE, Eipper BA. 60 YEARS OF POMC: From POMC and α-MSH to PAM, molecular oxygen, copper, and vitamin C. J Mol Endocrinol 2016; 56:T63-76. [PMID: 26667899 PMCID: PMC4899100 DOI: 10.1530/jme-15-0266] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 12/14/2015] [Indexed: 12/19/2022]
Abstract
A critical role for peptide C-terminal amidation was apparent when the first bioactive peptides were identified. The conversion of POMC into adrenocorticotropic hormone and then into α-melanocyte-stimulating hormone, an amidated peptide, provided a model system for identifying the amidating enzyme. Peptidylglycine α-amidating monooxygenase (PAM), the only enzyme that catalyzes this modification, is essential; mice lacking PAM survive only until mid-gestation. Purification and cloning led to the discovery that the amidation of peptidylglycine substrates proceeds in two steps: peptidylglycine α-hydroxylating monooxygenase catalyzes the copper- and ascorbate-dependent α-hydroxylation of the peptidylglycine substrate; peptidyl-α-hydroxyglycine α-amidating lyase cleaves the N-C bond, producing amidated product and glyoxylate. Both enzymes are contained in the luminal domain of PAM, a type 1 integral membrane protein. The structures of both catalytic cores have been determined, revealing how they interact with metals, molecular oxygen, and substrate to catalyze both reactions. Although not essential for activity, the intrinsically disordered cytosolic domain is essential for PAM trafficking. A phylogenetic survey led to the identification of bifunctional membrane PAM in Chlamydomonas, a unicellular eukaryote. Accumulating evidence points to a role for PAM in copper homeostasis and in retrograde signaling from the lumen of the secretory pathway to the nucleus. The discovery of PAM in cilia, cellular antennae that sense and respond to environmental stimuli, suggests that much remains to be learned about this ancient protein.
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Affiliation(s)
- Dhivya Kumar
- Departments of Molecular Biology and BiophysicsUniversity of Connecticut Health Center, Farmington, Connecticut, USA
| | - Richard E Mains
- Department of NeuroscienceUniversity of Connecticut Health Center, Farmington, Connecticut, USA
| | - Betty A Eipper
- Departments of Molecular Biology and BiophysicsUniversity of Connecticut Health Center, Farmington, Connecticut, USA Department of NeuroscienceUniversity of Connecticut Health Center, Farmington, Connecticut, USA
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19
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Kumar D, Blaby-Haas CE, Merchant SS, Mains RE, King SM, Eipper BA. Early eukaryotic origins for cilia-associated bioactive peptide-amidating activity. J Cell Sci 2016; 129:943-56. [PMID: 26787743 DOI: 10.1242/jcs.177410] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Accepted: 01/13/2016] [Indexed: 01/15/2023] Open
Abstract
Ciliary axonemes and basal bodies were present in the last eukaryotic common ancestor and play crucial roles in sensing and responding to environmental cues. Peptidergic signaling, generally considered a metazoan innovation, is essential for organismal development and homeostasis. Peptidylglycine α-amidating monooxygenase (PAM) is crucial for the last step of bioactive peptide biosynthesis. However, identification of a complete PAM-like gene in green algal genomes suggests ancient evolutionary roots for bioactive peptide signaling. We demonstrate that the Chlamydomonas reinhardtii PAM gene encodes an active peptide-amidating enzyme (CrPAM) that shares key structural and functional features with the mammalian enzyme, indicating that components of the peptide biosynthetic pathway predate multicellularity. In addition to its secretory pathway localization, CrPAM localizes to cilia and tightly associates with the axonemal superstructure, revealing a new axonemal enzyme activity. This localization pattern is conserved in mammals, with PAM present in both motile and immotile sensory cilia. The conserved ciliary localization of PAM adds to the known signaling capabilities of the eukaryotic cilium and provides a potential mechanistic link between peptidergic signaling and endocrine abnormalities commonly observed in ciliopathies.
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Affiliation(s)
- Dhivya Kumar
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, CT 06030-3401, USA
| | - Crysten E Blaby-Haas
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095-1569, USA
| | - Sabeeha S Merchant
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095-1569, USA Institute for Genomics and Proteomics, University of California, Los Angeles, CA 90095-1569, USA
| | - Richard E Mains
- Department of Neuroscience, University of Connecticut Health Center, Farmington, CT 06030-3401, USA
| | - Stephen M King
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, CT 06030-3401, USA
| | - Betty A Eipper
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, CT 06030-3401, USA Department of Neuroscience, University of Connecticut Health Center, Farmington, CT 06030-3401, USA
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20
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Zou X, He Y, Qiao J, Zhang C, Cao Z. The natural scorpion peptide, BmK NT1 activates voltage-gated sodium channels and produces neurotoxicity in primary cultured cerebellar granule cells. Toxicon 2016; 109:33-41. [DOI: 10.1016/j.toxicon.2015.11.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Revised: 09/15/2015] [Accepted: 11/05/2015] [Indexed: 11/26/2022]
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21
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Knight D, Iliadi KG, Iliadi N, Wilk R, Hu J, Krause HM, Taylor P, Moran MF, Boulianne GL. Distinct Regulation of Transmitter Release at the Drosophila NMJ by Different Isoforms of nemy. PLoS One 2015; 10:e0132548. [PMID: 26237434 PMCID: PMC4523183 DOI: 10.1371/journal.pone.0132548] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Accepted: 06/17/2015] [Indexed: 11/18/2022] Open
Abstract
Synaptic transmission is highly plastic and subject to regulation by a wide variety of neuromodulators and neuropeptides. In the present study, we have examined the role of isoforms of the cytochrome b561 homologue called no extended memory (nemy) in regulation of synaptic strength and plasticity at the neuromuscular junction (NMJ) of third instar larvae in Drosophila. Specifically, we generated two independent excisions of nemy that differentially affect the expression of nemy isoforms. We show that the nemy45 excision, which specifically reduces the expression of the longest splice form of nemy, leads to an increase in stimulus evoked transmitter release and altered synaptic plasticity at the NMJ. Conversely, the nemy26.2 excision, which appears to reduce the expression of all splice forms except the longest splice isoform, shows a reduction in stimulus evoked transmitter release, and enhanced synaptic plasticity. We further show that nemy45 mutants have reduced levels of amidated peptides similar to that observed in peptidyl-glycine hydryoxylating mono-oxygenase (PHM) mutants. In contrast, nemy26.2 mutants show no defects in peptide amidation but rather display a decrease in Tyramine β hydroxylase activity (TβH). Taken together, these results show non-redundant roles for the different nemy isoforms and shed light on the complex regulation of neuromodulators.
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Affiliation(s)
- David Knight
- Program in Developmental and Stem Cell Biology, Peter Gilgan Center for Research and Learning, The Hospital for Sick Children, Toronto, M5G 0A4, Canada
| | - Konstantin G. Iliadi
- Program in Developmental and Stem Cell Biology, Peter Gilgan Center for Research and Learning, The Hospital for Sick Children, Toronto, M5G 0A4, Canada
| | - Natalia Iliadi
- Program in Developmental and Stem Cell Biology, Peter Gilgan Center for Research and Learning, The Hospital for Sick Children, Toronto, M5G 0A4, Canada
| | - Ronit Wilk
- Department of Molecular Genetics, The Terrence Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, M5S 3E1, Canada
| | - Jack Hu
- Department of Molecular Genetics, The Terrence Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, M5S 3E1, Canada
| | - Henry M. Krause
- Department of Molecular Genetics, The Terrence Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, M5S 3E1, Canada
| | - Paul Taylor
- Program in Molecular Structure and Function, The Hospital for Sick Children, Toronto, M5G 1L7, Canada
| | - Michael F. Moran
- Dept of Molecular Genetics, University of Toronto, Toronto, Ontario, M5S 1A8, Canada
- Program in Molecular Structure and Function, The Hospital for Sick Children, Toronto, M5G 1L7, Canada
| | - Gabrielle L. Boulianne
- Program in Developmental and Stem Cell Biology, Peter Gilgan Center for Research and Learning, The Hospital for Sick Children, Toronto, M5G 0A4, Canada
- Dept of Molecular Genetics, University of Toronto, Toronto, Ontario, M5S 1A8, Canada
- * E-mail:
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22
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The Drosophila Prosecretory Transcription Factor dimmed Is Dynamically Regulated in Adult Enteroendocrine Cells and Protects Against Gram-Negative Infection. G3-GENES GENOMES GENETICS 2015; 5:1517-24. [PMID: 25999585 PMCID: PMC4502385 DOI: 10.1534/g3.115.019117] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The endocrine system employs peptide hormone signals to translate environmental changes into physiological responses. The diffuse endocrine system embedded in the gastrointestinal barrier epithelium is one of the largest and most diverse endocrine tissues. Furthermore, it is the only endocrine tissue in direct physical contact with the microbial environment of the gut lumen. However, it remains unclear how this sensory epithelium responds to specific pathogenic challenges in a dynamic and regulated manner. We demonstrate that the enteroendocrine cells of the adult Drosophila melanogaster midgut display a transient, sensitive, and systemic induction of the prosecretory factor dimmed (dimm) in response to the Gram-negative pathogen Pseudomonas entomophila (Pe). In enteroendocrine cells, dimm controls the levels of the targets Phm, dcat-4, and the peptide hormone, Allatostatin A. Finally, we identify dimm as a host factor that protects against Pe infection and controls the expression of antimicrobial peptides. We propose that dimm provides “gain” in enteroendocrine output during the adaptive response to episodic pathogen exposure.
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23
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Husson SJ, Reumer A, Temmerman L, De Haes W, Schoofs L, Mertens I, Baggerman G. Worm peptidomics. EUPA OPEN PROTEOMICS 2014. [DOI: 10.1016/j.euprot.2014.04.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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24
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Pauls D, Chen J, Reiher W, Vanselow JT, Schlosser A, Kahnt J, Wegener C. Peptidomics and processing of regulatory peptides in the fruit fly Drosophila. EUPA OPEN PROTEOMICS 2014. [DOI: 10.1016/j.euprot.2014.02.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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25
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Solomon EI, Heppner DE, Johnston EM, Ginsbach JW, Cirera J, Qayyum M, Kieber-Emmons MT, Kjaergaard CH, Hadt RG, Tian L. Copper active sites in biology. Chem Rev 2014; 114:3659-853. [PMID: 24588098 PMCID: PMC4040215 DOI: 10.1021/cr400327t] [Citation(s) in RCA: 1147] [Impact Index Per Article: 114.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
| | - David E. Heppner
- Department of Chemistry, Stanford University, Stanford, CA, 94305
| | | | - Jake W. Ginsbach
- Department of Chemistry, Stanford University, Stanford, CA, 94305
| | - Jordi Cirera
- Department of Chemistry, Stanford University, Stanford, CA, 94305
| | - Munzarin Qayyum
- Department of Chemistry, Stanford University, Stanford, CA, 94305
| | | | | | - Ryan G. Hadt
- Department of Chemistry, Stanford University, Stanford, CA, 94305
| | - Li Tian
- Department of Chemistry, Stanford University, Stanford, CA, 94305
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26
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Jeffries KA, Dempsey DR, Behari AL, Anderson RL, Merkler DJ. Drosophila melanogaster as a model system to study long-chain fatty acid amide metabolism. FEBS Lett 2014; 588:1596-602. [PMID: 24650760 DOI: 10.1016/j.febslet.2014.02.051] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Revised: 02/01/2014] [Accepted: 02/24/2014] [Indexed: 11/30/2022]
Abstract
Long-chain fatty acid amides are cell-signaling lipids identified in mammals and, recently, in invertebrates, as well. Many details regarding fatty acid amide metabolism remain unclear. Herein, we demonstrate that Drosophila melanogaster is an excellent model system for the study long-chain fatty acid amide metabolism as we have quantified the endogenous levels of N-acylglycines, N-acyldopamines, N-acylethanolamines, and primary fatty acid amides by LC/QTOF-MS. Growth of D. melanogaster on media supplemented with [1-(13)C]-palmitate lead to a family of (13)C-palmitate-labeled fatty acid amides in the fly heads. The [1-(13)C]-palmitate feeding studies provide insight into the biosynthesis of the fatty acid amides.
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Affiliation(s)
- Kristen A Jeffries
- Department of Chemistry, University of South Florida, Tampa, FL 33620, USA
| | - Daniel R Dempsey
- Department of Chemistry, University of South Florida, Tampa, FL 33620, USA
| | - Anita L Behari
- Department of Chemistry, University of South Florida, Tampa, FL 33620, USA
| | - Ryan L Anderson
- Department of Chemistry, University of South Florida, Tampa, FL 33620, USA
| | - David J Merkler
- Department of Chemistry, University of South Florida, Tampa, FL 33620, USA.
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27
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Salisbury JP, Boggio KJ, Hsu YWA, Quijada J, Sivachenko A, Gloeckner G, Kowalski PJ, Easterling ML, Rosbash M, Agar JN. A rapid MALDI-TOF mass spectrometry workflow for Drosophila melanogaster differential neuropeptidomics. Mol Brain 2013; 6:60. [PMID: 24373546 PMCID: PMC4022047 DOI: 10.1186/1756-6606-6-60] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Accepted: 12/20/2013] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Neuropeptides are a diverse category of signaling molecules in the nervous system regulating a variety of processes including food intake, social behavior, circadian rhythms, learning, and memory. Both the identification and functional characterization of specific neuropeptides are ongoing fields of research. Matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) analysis of nervous tissues from a variety of organisms allows direct detection and identification of neuropeptides. Here, we demonstrate an analysis workflow that allows for the detection of differences in specific neuropeptides amongst a variety of neuropeptides being simultaneously measured. For sample preparation, we describe a straight-forward and rapid (minutes) method where individual adult Drosophila melanogaster brains are analyzed. Using a MATLAB-based data analysis workflow, also compatible with MALDI-TOF mass spectra obtained from other sample preparations and instrumentation, we demonstrate how changes in neuropeptides levels can be detected with this method. RESULTS Over fifty isotopically resolved ion signals in the peptide mass range are reproducibly observed across experiments. MALDI-TOF MS profile spectra were used to statistically identify distinct relative differences in organ-wide endogenous levels of detected neuropeptides between biological conditions. In particular, three distinct levels of a particular neuropeptide, pigment dispersing factor, were detected by comparing groups of preprocessed spectra obtained from individual brains across three different D. melanogaster strains, each of which express different amounts of this neuropeptide. Using the same sample preparation, MALDI-TOF/TOF tandem mass spectrometry confirmed that at least 14 ion signals observed across experiments are indeed neuropeptides. Among the identified neuropeptides were three products of the neuropeptide-like precursor 1 gene previously not identified in the literature. CONCLUSIONS Using MALDI-TOF MS and preprocessing/statistical analysis, changes in relative levels of a particular neuropeptide in D. melanogaster tissue can be statistically detected amongst a variety of neuropeptides. While the data analysis methods should be compatible with other sample preparations, the presented sample preparation method was sufficient to identify previously unconfirmed D. melanogaster neuropeptides.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | - Jeffrey N Agar
- Depts of Chemistry and Chemical Biology and Pharmaceutical Sciences and Barnett Institute of Chemical and Biological Analysis, Northeastern University, 140 The Fenway, Boston, MA 02115, USA.
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28
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Ul-Hasan S, Burgess DM, Gajewiak J, Li Q, Hu H, Yandell M, Olivera BM, Bandyopadhyay PK. Characterization of the peptidylglycine α-amidating monooxygenase (PAM) from the venom ducts of neogastropods, Conus bullatus and Conus geographus. Toxicon 2013; 74:215-24. [PMID: 23994590 DOI: 10.1016/j.toxicon.2013.08.054] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Revised: 08/15/2013] [Accepted: 08/21/2013] [Indexed: 11/29/2022]
Abstract
Cone snails, genus Conus, are predatory marine snails that use venom to capture their prey. This venom contains a diverse array of peptide toxins, known as conotoxins, which undergo a diverse set of posttranslational modifications. Amidating enzymes modify peptides and proteins containing a C-terminal glycine residue, resulting in loss of the glycine residue and amidation of the preceding residue. A significant fraction of peptides present in the venom of cone snails contain C-terminal amidated residues, which are important for optimizing biological activity. This study describes the characterization of the amidating enzyme, peptidylglycine α-amidating monooxygenase (PAM), present in the venom duct of cone snails, Conus bullatus and Conus geographus. PAM is known to carry out two functions, peptidyl α-hydroxylating monooxygenase (PHM) and peptidylamido-glycolate lyase (PAL). In some animals, such as Drosophila melanogaster, these two functions are present in separate polypeptides, working as individual enzymes. In other animals, such as mammals and in Aplysia californica, PAM activity resides in a single, bifunctional polypeptide. Using specific oligonucleotide primers and reverse transcription-polymerase chain reaction we have identified and cloned from the venom duct cDNA library, a cDNA with 49% homology to PAM from A. californica. We have determined that both the PHM and PAL activities are encoded in one mRNA polynucleotide in both C. bullatus and C. geographus. We have directly demonstrated enzymatic activity catalyzing the conversion of dansyl-YVG-COOH to dansyl-YV-NH2 in cloned cDNA expressed in Drosophila S2 cells.
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Affiliation(s)
- Sabah Ul-Hasan
- Department of Biology, University of Utah, 257 South 1400 East, Salt Lake City, UT 84112, USA
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29
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Cui W, Niu S, Zheng L, Hu L, Huang T, Gu L, Feng K, Zhang N, Cai Y, Li Y. Prediction of protein amidation sites by feature selection and analysis. Mol Genet Genomics 2013; 288:391-400. [DOI: 10.1007/s00438-013-0760-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Accepted: 06/10/2013] [Indexed: 11/25/2022]
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30
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Abstract
Peptide hormones with a C-terminal amide regulate numerous physiological processes and are associated with many disease states. Consequently, the key enzymes involved in their production, peptidylglycine α-amidating monooxygenase and carboxypeptidase E, have been studied intensively. This review surveys what is known about the enzymes themselves and their cofactors, as well as their substrates and competitive and mechanism-based inhibitors.
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Sellami A, Wegener C, Veenstra JA. Functional significance of the copper transporter ATP7 in peptidergic neurons and endocrine cells inDrosophila melanogaster. FEBS Lett 2012; 586:3633-8. [DOI: 10.1016/j.febslet.2012.08.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2011] [Revised: 08/03/2012] [Accepted: 08/06/2012] [Indexed: 10/28/2022]
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Attenborough RMF, Hayward DC, Kitahara MV, Miller DJ, Ball EE. A "neural" enzyme in nonbilaterian animals and algae: preneural origins for peptidylglycine α-amidating monooxygenase. Mol Biol Evol 2012; 29:3095-109. [PMID: 22496439 DOI: 10.1093/molbev/mss114] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Secreted peptides, produced by enzymatic processing of larger precursor molecules, are found throughout the animal kingdom and play important regulatory roles as neurotransmitters and hormones. Many require a carboxy-terminal modification, involving the conversion of a glycine residue into an α-amide, for their biological activity. Two sequential enzymatic activities catalyze this conversion: a monooxygenase (peptidylglycine α-hydroxylating monooxygenase or PHM) and an amidating lyase (peptidyl-α-hydroxyglycine α-amidating lyase or PAL). In vertebrates, these activities reside in a single polypeptide known as peptidylglycine α-amidating monooxygenase (PAM), which has been extensively studied in the context of neuropeptide modification. Bifunctional PAMs have been reported from some invertebrates, but the phylogenetic distribution of PAMs and their evolutionary relationship to PALs and PHMs is unclear. Here, we report sequence and expression data for two PAMs from the coral Acropora millepora (Anthozoa, Cnidaria), as well as providing a comprehensive survey of the available sequence data from other organisms. These analyses indicate that bifunctional PAMs predate the origins of the nervous and endocrine systems, consistent with the idea that within the Metazoa their ancestral function may have been to amidate epitheliopeptides. More surprisingly, the phylogenomic survey also revealed the presence of PAMs in green algae (but not in higher plants or fungi), implying that the bifunctional enzyme either predates the plant/animal divergence and has subsequently been lost in a number of lineages or perhaps that convergent evolution or lateral gene transfer has occurred. This finding is consistent with recent discoveries that other molecules once thought of as "neural" predate nervous systems.
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Affiliation(s)
- Rosalind M F Attenborough
- Evolution, Ecology and Genetics, Research School of Biology, Australian National University, Canberra, ACT 0200, Australia
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Yin P, Bousquet-Moore D, Annangudi SP, Southey BR, Mains RE, Eipper BA, Sweedler JV. Probing the production of amidated peptides following genetic and dietary copper manipulations. PLoS One 2011; 6:e28679. [PMID: 22194882 PMCID: PMC3241674 DOI: 10.1371/journal.pone.0028679] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2011] [Accepted: 11/13/2011] [Indexed: 11/23/2022] Open
Abstract
Amidated neuropeptides play essential roles throughout the nervous and endocrine systems. Mice lacking peptidylglycine α-amidating monooxygenase (PAM), the only enzyme capable of producing amidated peptides, are not viable. In the amidation reaction, the reactant (glycine-extended peptide) is converted into a reaction intermediate (hydroxyglycine-extended peptide) by the copper-dependent peptidylglycine-α-hydroxylating monooxygenase (PHM) domain of PAM. The hydroxyglycine-extended peptide is then converted into amidated product by the peptidyl-α-hydroxyglycine α-amidating lyase (PAL) domain of PAM. PHM and PAL are stitched together in vertebrates, but separated in some invertebrates such as Drosophila and Hydra. In addition to its luminal catalytic domains, PAM includes a cytosolic domain that can enter the nucleus following release from the membrane by γ-secretase. In this work, several glycine- and hydroxyglycine-extended peptides as well as amidated peptides were qualitatively and quantitatively assessed from pituitaries of wild-type mice and mice with a single copy of the Pam gene (PAM+/−) via liquid chromatography-mass spectrometry-based methods. We provide the first evidence for the presence of a peptidyl-α-hydroxyglycine in vivo, indicating that the reaction intermediate becomes free and is not handed directly from PHM to PAL in vertebrates. Wild-type mice fed a copper deficient diet and PAM+/− mice exhibit similar behavioral deficits. While glycine-extended reaction intermediates accumulated in the PAM+/− mice and reflected dietary copper availability, amidated products were far more prevalent under the conditions examined, suggesting that the behavioral deficits observed do not simply reflect a lack of amidated peptides.
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Affiliation(s)
- Ping Yin
- Department of Chemistry, Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Danielle Bousquet-Moore
- Department of Neuroscience, University of Connecticut Health Center, Farmington, Connecticut, United States of America
| | - Suresh P. Annangudi
- Department of Chemistry, Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Bruce R. Southey
- Department of Chemistry, Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Richard E. Mains
- Department of Neuroscience, University of Connecticut Health Center, Farmington, Connecticut, United States of America
| | - Betty A. Eipper
- Department of Neuroscience, University of Connecticut Health Center, Farmington, Connecticut, United States of America
- * E-mail: (JVS); (BAE)
| | - Jonathan V. Sweedler
- Department of Chemistry, Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
- * E-mail: (JVS); (BAE)
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Vidal-Dupiol J, Ladrière O, Destoumieux-Garzón D, Sautière PE, Meistertzheim AL, Tambutté E, Tambutté S, Duval D, Fouré L, Adjeroud M, Mitta G. Innate immune responses of a scleractinian coral to vibriosis. J Biol Chem 2011; 286:22688-98. [PMID: 21536670 PMCID: PMC3121412 DOI: 10.1074/jbc.m110.216358] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2010] [Revised: 04/15/2011] [Indexed: 11/06/2022] Open
Abstract
Scleractinian corals are the most basal eumetazoan taxon and provide the biological and physical framework for coral reefs, which are among the most diverse of all ecosystems. Over the past three decades and coincident with climate change, these phototrophic symbiotic organisms have been subject to increasingly frequent and severe diseases, which are now geographically widespread and a major threat to these ecosystems. Although coral immunity has been the subject of increasing study, the available information remains fragmentary, especially with respect to coral antimicrobial responses. In this study, we characterized damicornin from Pocillopora damicornis, the first scleractinian antimicrobial peptide (AMP) to be reported. We found that its precursor has a segmented organization comprising a signal peptide, an acidic proregion, and the C-terminal AMP. The 40-residue AMP is cationic, C-terminally amidated, and characterized by the presence of six cysteine molecules joined by three intramolecular disulfide bridges. Its cysteine array is common to another AMP and toxins from cnidarians; this suggests a common ancestor, as has been proposed for AMPs and toxins from arthropods. Damicornin was active in vitro against Gram-positive bacteria and the fungus Fusarium oxysporum. Damicornin expression was studied using a combination of immunohistochemistry, reverse phase HPLC, and quantitative RT-PCR. Our data show that damicornin is constitutively transcribed in ectodermal granular cells, where it is stored, and further released in response to nonpathogenic immune challenge. Damicornin gene expression was repressed by the coral pathogen Vibrio coralliilyticus. This is the first evidence of AMP gene repression in a host-Vibrio interaction.
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Affiliation(s)
- Jeremie Vidal-Dupiol
- From the UMR 5244, CNRS UPVD EPHE, Université de Perpignan Via Domitia, 66000 Perpignan, France
| | - Ophélie Ladrière
- the Unité d'Ecologie Marine, Laboratoire d'Ecologie Animale et Ecotoxicologie, Université de Liège, 4000 Liège, Belgium
| | | | - Pierre-Eric Sautière
- the Université Lille Nord de France, Université Lille 1, Sciences et Technologies, CNRS FRE 3249, IFR 147, 59655 Villeneuve d'Ascq, France
| | | | - Eric Tambutté
- the Centre Scientifique de Monaco, 98000 Monaco, Principality of Monaco
| | - Sylvie Tambutté
- the Centre Scientifique de Monaco, 98000 Monaco, Principality of Monaco
| | - David Duval
- From the UMR 5244, CNRS UPVD EPHE, Université de Perpignan Via Domitia, 66000 Perpignan, France
| | - Laurent Fouré
- the Aquarium du Cap d'Agde, 34300 Cap d'Agde, France, and
| | - Mehdi Adjeroud
- From the UMR 5244, CNRS UPVD EPHE, Université de Perpignan Via Domitia, 66000 Perpignan, France
- the Institut de Recherche pour le Développement, Unité 227 CoRéUs2, “Biocomplexité des Ecosystèmes Coralliens de l'Indo-Pacifique,” 98848 Noumea, New Caledonia
| | - Guillaume Mitta
- From the UMR 5244, CNRS UPVD EPHE, Université de Perpignan Via Domitia, 66000 Perpignan, France
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Bousquet-Moore D, Mains RE, Eipper BA. Peptidylgycine α-amidating monooxygenase and copper: a gene-nutrient interaction critical to nervous system function. J Neurosci Res 2011; 88:2535-45. [PMID: 20648645 DOI: 10.1002/jnr.22404] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Peptidylgycine alpha-amidating monooxygenase (PAM), a highly conserved copper-dependent enzyme, is essential for the synthesis of all amidated neuropeptides. Biophysical studies revealed that the binding of copper to PAM affects its structure, and cell biological studies demonstrated that the endocytic trafficking of PAM was sensitive to copper. We review data indicating that genetic reduction of PAM expression and mild copper deficiency in mice cause similar alterations in several physiological functions known to be regulated by neuropeptides: thermal regulation, seizure sensitivity, and anxiety-like behavior.
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Abstract
In a search for more environmentally benign alternatives to chemical pesticides, insect neuropeptides have been suggested as ideal candidates. Neuropeptides are neuromodulators and/or neurohormones that regulate most major physiological and behavioral processes in insects. The major neuropeptide structures have been identified through peptide purification in insects (peptidomics) and insect genome projects. Neuropeptide receptors have been identified and characterized in Drosophila and similar receptors are being targeted in other insects considered to be economically detrimental pests in agriculture and forestry. Defining neuropeptide action in different insect systems has been more challenging and as a consequence, identifying unique targets for potential pest control is also a challenge. In this chapter, neuropeptide biosynthesis as well as select physiological processes are examined with a view to pest control targets. The application of molecular techniques to transform insects with neuropeptide or neuropeptide receptor genes, or knockout genes to identify potential pest control targets, is a relatively new area that offers promise to insect control. Insect immune systems may also be manipulated through neuropeptides which may aid in compromising the insects ability to defend against foreign invasion.
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A PAL for Schistosoma mansoni PHM. Mol Biochem Parasitol 2010; 173:97-106. [PMID: 20488212 DOI: 10.1016/j.molbiopara.2010.05.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2010] [Revised: 05/10/2010] [Accepted: 05/11/2010] [Indexed: 11/23/2022]
Abstract
Parasitic helminth neuromuscular function is a proven target for chemotherapeutic control. Although neuropeptide signalling plays a key role in helminth motor function, it has not yet provided targets for known anthelmintics. The majority of biologically active neuropeptides display a C-terminal amide (NH(2)) motif, generated exclusively by the sequential action of two enzymes, peptidylglycine alpha-hydroxylating monooxygenase (PHM) and peptidylglycine alpha-amidating lyase (PAL). Further to our previous description of a monofunctional PHM enzyme (SmPHM) from the human blood fluke Schistosoma mansoni, here we describe a cDNA encoding S. mansoni PAL (SmPAL). SmPAL is a monofunctional enzyme which, following heterologous expression, we find to have functionally similar catalytic activity and optimal pH values, but key catalytic core amino acid substitutions, when compared to other known PALs including those found in humans. We have used in situ hybridisation to demonstrate that in adult schistosomes, SmPAL mRNA (Sm-pal-1) is expressed in neuronal cell bodies of the central nervous system, consistent with a role for amidated neuropeptides in S. mansoni neuromuscular function. In order to validate SmPAL as a putative drug target we applied published RNA interference (RNAi) methods in efforts to trigger knockdown of Sm-pal-1 transcript in larval schistosomula. Although transcript knockdown was recorded on several occasions, silencing was variable and inconsistent and did not associate with any observable aberrant phenotype. The inconsistent outcomes of RNAi suggest that there may be tissue-specific differences in the applicability of RNAi methods for S. mansoni, with neuronal targets proving more difficult or refractory to knockdown. The key role played by schistosome amidating enzymes in neuropeptide maturation make them appealing as drug targets; their validation as such will depend on the development of more robust reverse genetic tools to facilitate efficient neuronal gene function studies.
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Chufán EE, De M, Eipper BA, Mains RE, Amzel LM. Amidation of bioactive peptides: the structure of the lyase domain of the amidating enzyme. Structure 2009; 17:965-73. [PMID: 19604476 DOI: 10.1016/j.str.2009.05.008] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2009] [Revised: 04/29/2009] [Accepted: 05/01/2009] [Indexed: 11/26/2022]
Abstract
Many neuropeptides and peptide hormones require amidation of their carboxy terminal for full biological activity. The enzyme peptidyl-alpha-hydroxyglycine alpha-amidating lyase (PAL; EC 4.3.2.5) catalyzes the second and last step of this reaction, N-dealkylation of the peptidyl-alpha-hydroxyglycine to generate the alpha-amidated peptide and glyoxylate. Here we report the X-ray crystal structure of the PAL catalytic core (PALcc) alone and in complex with the nonpeptidic substrate alpha-hydroxyhippuric acid. The structures show that PAL folds as a six-bladed beta-propeller. The active site is formed by a Zn(II) ion coordinated by three histidine residues; the substrate binds to this site with its alpha-hydroxyl group coordinated to the Zn(II) ion. The structures also reveal a tyrosine residue (Tyr(654)) at the active site as the catalytic base for hydroxyl deprotonation, an unusual role for tyrosine. A reaction mechanism is proposed based on this structural data and validated by biochemical analysis of site-directed PALcc mutants.
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Affiliation(s)
- Eduardo E Chufán
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins School of Medicine, Johns Hopkins University, Baltimore, MD 21205, USA
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McIntyre NR, Lowe EW, Merkler DJ. Imino-oxy acetic acid dealkylation as evidence for an inner-sphere alcohol intermediate in the reaction catalyzed by peptidylglycine alpha-hydroxylating monooxygenase. J Am Chem Soc 2009; 131:10308-19. [PMID: 19569683 DOI: 10.1021/ja902716d] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Peptidylglycine alpha-hydroxylating monooxygenase (PHM, EC 1.14.17.3) catalyzes the stereospecific hydroxylation of a glycyl alpha-carbon in a reaction that requires O(2) and ascorbate. Subsequent dealkylation of the alpha-hydroxyglycine by another enzyme, peptidylamidoglycolate lyase (PAL. EC 4.3.2.5), yields a bioactive amide and glyoxylate. PHM is a noncoupled, type II dicopper monooxygenase which activates O(2) at only a single copper atom, Cu(M). In this study, the PHM mechanism was probed using a non-natural substrate, benzaldehyde imino-oxy acetic acid (BIAA). PHM catalyzes the O-oxidative dealkylation of BIAA to benzaldoxime and glyoxylate with no involvement of PAL. The minimal kinetic mechanism for BIAA was shown to be steady-state ordered using primary deuterium kinetic isotope effects. The (D)(V/K)(APPARENT, BIAA) decreased from 14.7 +/- 1.0 as [O(2)] --> 0 to 1.0 +/- 0.2 as [O(2)] --> infinity suggesting the dissociation rate constant from the PHM x BIAA complex decreases as [O(2)] increases; thereby, reducing the steady-state concentration of [PHM](free). BIAA was further used to differentiate between potential oxidative Cu/O species using a QM/MM reaction coordinate simulation to determine which species could yield product O-dealkylation that matched our experimental data. The results of this study provided compelling evidence for the presence of a covalently linked Cu(II)-alkoxide intermediate with a quartet spin state responsible BIAA oxidation.
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Affiliation(s)
- Neil R McIntyre
- Department of Chemistry, University of South Florida, 4202 East Fowler Avenue, Tampa, Florida 33620, USA
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Park D, Taghert PH. Peptidergic neurosecretory cells in insects: organization and control by the bHLH protein DIMMED. Gen Comp Endocrinol 2009; 162:2-7. [PMID: 19135054 DOI: 10.1016/j.ygcen.2008.12.012] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2008] [Revised: 11/19/2008] [Accepted: 12/10/2008] [Indexed: 11/15/2022]
Abstract
This review considers evidence that defines a role for the transcription factor DIMMED in the regulation of insect neurosecretory cells. Genetic anatomical and molecular data all suggest DIMMED is a dedicated controller of the regulated secretory pathway. DIMM is normally expressed within diverse neuropeptide-expressing cells and appears highly correlated with a neurosecretory cell fate. Loss of DIMM is associated with deficits in display of neuropeptides and neuropeptide-associated enzymes. Gain of DIMM promotes such display in peptidergic cells and can confer such neurosecretory properties onto conventional neurons. We review models proposed to explain how DIMMED regulates these essential cellular properties.
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Affiliation(s)
- Dongkook Park
- Department of Anatomy & Neurobiology, Washington University Medical School, 660 South Euclid Avenue, Saint Louis, MO 63110, USA.
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nemy encodes a cytochrome b561 that is required for Drosophila learning and memory. Proc Natl Acad Sci U S A 2008; 105:19986-91. [PMID: 19064935 DOI: 10.1073/pnas.0810698105] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Although many genes have been shown to play essential roles in learning and memory, the precise molecular and cellular mechanisms underlying these processes remain to be fully elucidated. Here, we present the molecular and behavioral characterization of the Drosophila memory mutant nemy. We provide multiple lines of evidence to show that nemy arises from a mutation in a Drosophila homologue of cytochrome B561. nemy is predominantly expressed in neuroendocrine neurons in the larval brain, and in mushroom bodies and antennal lobes in the adult brain, where it is partially coexpressed with peptidyl alpha-hydroxylating monooxygenase (PHM), an enzyme required for peptide amidation. Cytochrome b561 was found to be a requisite cofactor for PHM activity and we found that the levels of amidated peptides were reduced in nemy mutants. Moreover, we found that knockdown of PHM gave rise to defects in memory retention. Altogether, the data are consistent with a model whereby cytochrome B561-mediated electron transport plays a role in memory formation by regulating intravesicular PHM activity and the formation of amidated neuropeptides.
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Merkler DJ, Asser AS, Baumgart LE, Carballo N, Carpenter SE, Chew GH, Cosner CC, Dusi J, Galloway LC, Lowe AB, Lowe EW, King L, Kendig RD, Kline PC, Malka R, Merkler KA, McIntyre NR, Romero M, Wilcox BJ, Owen TC. Substituted hippurates and hippurate analogs as substrates and inhibitors of peptidylglycine alpha-hydroxylating monooxygenase (PHM). Bioorg Med Chem 2008; 16:10061-74. [PMID: 18952446 DOI: 10.1016/j.bmc.2008.10.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2008] [Revised: 10/03/2008] [Accepted: 10/04/2008] [Indexed: 10/21/2022]
Abstract
Peptidyl alpha-hydroxylating monooxygenase (PHM) functions in vivo towards the biosynthesis of alpha-amidated peptide hormones in mammals and insects. PHM is a potential target for the development of inhibitors as drugs for the treatment of human disease and as insecticides for the management of insect pests. We show here that relatively simple ground state analogs of the PHM substrate hippuric acid (C(6)H(5)-CO-NH-CH(2)-COOH) inhibit the enzyme with K(i) values as low as 0.5microM. Substitution of sulfur atom(s) into the hippuric acid analog increases the affinity of PHM for the inhibitor. Replacement of the acetylglycine moiety, -CO-NH-CH(2)-COOH with an S-(thioacetyl)thioglycolic acid moiety, -CS-S-CH(2)-COOH, yields compounds with the highest PHM affinity. Both S-(2-phenylthioacetyl)thioglycolate and S-(4-ethylthiobenzoyl)thioglycolic acid inhibit the proliferation of cultured human prostate cancer cells at concentrations >100-fold excess of their respective K(i) values. Comparison of K(i) values between mammalian PHM and insect PHM shows differences in potency suggesting that a PHM-based insecticide with limited human toxicity can be developed.
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Affiliation(s)
- David J Merkler
- Department of Chemistry, University of South Florida, 4202 E. Fowler Ave., Tampa, FL 33620, USA.
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43
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Park D, Veenstra JA, Park JH, Taghert PH. Mapping peptidergic cells in Drosophila: where DIMM fits in. PLoS One 2008; 3:e1896. [PMID: 18365028 PMCID: PMC2266995 DOI: 10.1371/journal.pone.0001896] [Citation(s) in RCA: 143] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2008] [Accepted: 02/22/2008] [Indexed: 11/24/2022] Open
Abstract
The bHLH transcription factor DIMMED has been associated with the differentiation of peptidergic cells in Drosophila. However, whether all Drosophila peptidergic cells express DIMM, and the extent to which all DIMM cells are peptidergic, have not been determined. To address these issues, we have mapped DIMM expression in the central nervous system (CNS) and periphery in the late larval stage Drosophila. At 100 hr after egg-laying, DIMM immunosignals are largely congruent with a dimm-promoter reporter (c929-GAL4) and they present a stereotyped pattern of 306 CNS cells and 52 peripheral cells. We assigned positional values for all DIMM CNS cells with respect to reference gene expression patterns, or to patterns of secondary neuroblast lineages. We could assign provisional peptide identities to 68% of DIMM-expressing CNS cells (207/306) and to 73% of DIMM-expressing peripheral cells (38/52) using a panel of 24 markers for Drosophila neuropeptide genes. Furthermore, we found that DIMM co-expression was a prevalent feature within single neuropeptide marker expression patterns. Of the 24 CNS neuropeptide gene patterns we studied, six patterns are >90% DIMM-positive, while 16 of 22 patterns are >40% DIMM-positive. Thus most or all DIMM cells in Drosophila appear to be peptidergic, and many but not all peptidergic cells express DIMM. The co-incidence of DIMM-expression among peptidergic cells is best explained by a hypothesis that DIMM promotes a specific neurosecretory phenotype we term LEAP. LEAP denotes Large cells that display Episodic release of Amidated Peptides.
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Affiliation(s)
- Dongkook Park
- Department of Anatomy and Neurobiology, Washington University School of Medicine, Saint Louis, Missouri, United States of America
| | | | - Jae H. Park
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee–Knoxville, Knoxville, Tennessee, United States of America
| | - Paul H. Taghert
- Department of Anatomy and Neurobiology, Washington University School of Medicine, Saint Louis, Missouri, United States of America
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Abstract
alpha-Amidation is a terminal modification in peptide biosynthesis that can itself be rate-limiting in the overall production of bioactive alpha-amidated peptides. More than half of the known neural and endocrine peptides are alpha-amidated and in most cases, this structural feature is essential for receptor recognition, signal transduction, and thus, biologic function. This chapter describes methods for developing and using analytical tools to study the biology of alpha-amidated peptides. The principle analytical method used to quantify alpha-amidated peptides is the radioimmunoassay (RIA). Detailed protocols are provided for 1) primary antibody production and characterization; 2) radiolabeling of RIA peptides; 3) sample preparation; and 4) the performance of the RIA itself. Techniques are also described for the identification and verification of alpha-amidated peptides. Lastly, in vivo models used for studying the biology of alpha-amidation are discussed.
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Affiliation(s)
- Gregory P Mueller
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
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The Drosophila basic helix-loop-helix protein DIMMED directly activates PHM, a gene encoding a neuropeptide-amidating enzyme. Mol Cell Biol 2007; 28:410-21. [PMID: 17967878 DOI: 10.1128/mcb.01104-07] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The basic helix-loop-helix (bHLH) protein DIMMED (DIMM) supports the differentiation of secretory properties in numerous peptidergic cells of Drosophila melanogaster. DIMM is coexpressed with diverse amidated neuropeptides and with the amidating enzyme peptidylglycine alpha-hydroxylating monooxygenase (PHM) in approximately 300 cells of the late embryo. Here we confirm that DIMM has transcription factor activity in transfected HEK 293 cells and that the PHM gene is a direct target. The mammalian DIMM orthologue MIST1 also transactivated the PHM gene. DIMM activity was dependent on the basic region of the protein and on the sequences of three E-box sites within PHM's first intron; the sites make different contributions to the total activity. These data suggest a model whereby the three E boxes interact cooperatively and independently to produce high PHM transcriptional activation. This DIMM-controlled PHM regulatory region displayed similar properties in vivo. Spatially, its expression mirrored that of the DIMM protein, and its activity was largely dependent on dimm. Further, in vivo expression was highly dependent on the sequences of the same three E boxes. This study supports the hypothesis that DIMM is a master regulator of a peptidergic cell fate in Drosophila and provides a detailed transcriptional mechanism of DIMM action on a defined target gene.
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Husson SJ, Janssen T, Baggerman G, Bogert B, Kahn-Kirby AH, Ashrafi K, Schoofs L. Impaired processing of FLP and NLP peptides in carboxypeptidase E (EGL-21)-deficient Caenorhabditis elegans as analyzed by mass spectrometry. J Neurochem 2007; 102:246-60. [PMID: 17564681 DOI: 10.1111/j.1471-4159.2007.04474.x] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Biologically active peptides are synthesized from inactive pre-proproteins or peptide precursors by the sequential actions of processing enzymes. Proprotein convertases cleave the precursor at pairs of basic amino acids, which are then removed from the carboxyl terminus of the generated fragments by a specific carboxypeptidase. Caenorhabditis elegans strains lacking proprotein convertase EGL-3 display a severely impaired neuropeptide profile (Husson et al. 2006, J. Neurochem.98, 1999-2012). In the present study, we examined the role of the C. elegans carboxypeptidase E orthologue EGL-21 in the processing of peptide precursors. More than 100 carboxy-terminally extended neuropeptides were detected in egl-21 mutant strains. These findings suggest that EGL-21 is a major carboxypeptidase involved in the processing of FMRFamide-like peptide (FLP) precursors and neuropeptide-like protein (NLP) precursors. The impaired peptide profile of egl-3 and egl-21 mutants is reflected in some similar phenotypes. They both share a severe widening of the intestinal lumen, locomotion defects, and retention of embryos. In addition, egl-3 animals have decreased intestinal fat content. Taken together, these results suggest that EGL-3 and EGL-21 are key enzymes for the proper processing of neuropeptides that control egg-laying, locomotion, fat storage and the nutritional status.
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Affiliation(s)
- Steven J Husson
- Functional Genomics and Proteomics Unit, Department of Biology, Katholieke Universiteit Leuven, Leuven, Belgium.
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Husson SJ, Mertens I, Janssen T, Lindemans M, Schoofs L. Neuropeptidergic signaling in the nematode Caenorhabditis elegans. Prog Neurobiol 2007; 82:33-55. [PMID: 17383075 DOI: 10.1016/j.pneurobio.2007.01.006] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2006] [Revised: 12/14/2006] [Accepted: 01/29/2007] [Indexed: 11/25/2022]
Abstract
The nematode Caenorhabditis elegans joins the menagerie of behavioral model systems next to the fruit fly Drosophila melanogaster, the marine snail Aplysia californica and the mouse. In contrast to Aplysia, which contains 20,000 neurons having cell bodies of hundreds of microns in diameter, C. elegans harbors only 302 tiny neurons from which the cell lineage is completely described, as is the case for all the other somatic cells. As such, this nervous system appears at first sight incommensurable with those of higher organisms, although genome-wide comparison of predicted C. elegans genes with their counterparts in vertebrates revealed many parallels. Together with its short lifespan and ease of cultivation, suitability for high-throughput genetic screenings and genome-wide RNA interference approaches, access to an advanced genetic toolkit and cell-ablation techniques, it seems that this tiny transparent organism of only 1mm in length has nothing to hide. Recently, highly exciting developments have occurred within the field of neuropeptidergic signaling in C. elegans, not only because of the availability of a sequenced genome since 1998, but especially because of state of the art post genomic technologies, that allow for molecular characterization of the signaling molecules. Here, we will focus on endogenous, bioactive (neuro)peptides and mainly discuss biosynthesis, peptide sequence information, localization and G-protein coupled receptors of the three major peptide families in C. elegans.
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Affiliation(s)
- Steven J Husson
- Functional Genomics and Proteomics Unit, Department of Biology, Katholieke Universiteit Leuven, Naamsestraat 59, B-3000 Leuven, Belgium.
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De M, Bell J, Blackburn NJ, Mains RE, Eipper BA. Role for an essential tyrosine in peptide amidation. J Biol Chem 2006; 281:20873-20882. [PMID: 16704972 DOI: 10.1074/jbc.m513886200] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The catalytic core of the peptidyl-alpha-hydroxyglycine alpha-amidating lyase (PAL) domain of peptidylglycine alpha-amidating monooxygenase was investigated with respect to its ability to function as a ureidoglycolate lyase and the identity and role of its bound metal ions. The purified PAL catalytic core (PALcc) contains molar equivalents of calcium and zinc along with substoichiometric amounts of iron and functions as a ureidoglycolate lyase. Limiting iron availability in the cells synthesizing PALcc reduces the specific activity of the enzyme produced. Concentrated samples of native PALcc have an absorption maximum at 560 nm, suggestive of a phenolate-Fe(III) charge transfer complex. An essential role for a Tyr residue was confirmed by elimination of PAL activity following site-directed mutagenesis. Purified PALcc in which the only conserved Tyr residue (Tyr(654)) was mutated to Phe was secreted normally, but was catalytically inactive and lacked bound iron and bound zinc. Our data demonstrate an essential role for Tyr(654) and suggest that it serves as an Fe(III) ligand in an essential iron-zinc bimetallic site.
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Affiliation(s)
- Mithu De
- Neuroscience Department, University of Connecticut Health Center, Farmington, Connecticut 06030-3401
| | - Joseph Bell
- Neuroscience Department, University of Connecticut Health Center, Farmington, Connecticut 06030-3401
| | - Ninian J Blackburn
- Neuroscience Department, University of Connecticut Health Center, Farmington, Connecticut 06030-3401
| | - Richard E Mains
- Neuroscience Department, University of Connecticut Health Center, Farmington, Connecticut 06030-3401
| | - Betty A Eipper
- Neuroscience Department, University of Connecticut Health Center, Farmington, Connecticut 06030-3401.
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Sidyelyeva G, Baker NE, Fricker LD. Characterization of the molecular basis of the Drosophila mutations in carboxypeptidase D. Effect on enzyme activity and expression. J Biol Chem 2006; 281:13844-13852. [PMID: 16556608 DOI: 10.1074/jbc.m513499200] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Carboxypeptidase D (CPD) functions in the processing of proteins and peptides in the secretory pathway. Drosophila CPD is encoded by the silver gene (svr), which is differentially spliced to produce long transmembrane protein forms with three metallocarboxypeptidase (CP)-like domains and short soluble forms with a single CP domain. Many svr mutants have been reported, but the precise molecular defects have not been previously determined. In the present study, three mutant lines were characterized. svr (PG33) mutants do not survive past the early larval stage. These mutants have a P-element insertion within exon 1B upstream of the initiation ATG, which greatly reduces mRNA levels of all forms of CPD. Both svr (1) and svr (poi) mutants are viable, with a silvery body color and pointed wings. The wing shape is generally similar between these two mutants, although svr (poi) mutants have smaller wings. The svr (1) gene has a three-nucleotide deletion in exon 6, removing a leucine in a region of the protein predicted to function as a folding domain for the second CP-like domain. svr (poi) has a 1072-bp duplication of the gene that introduces a stop codon into the open reading frame, causing the truncation of the protein in the middle of the second CP-like domain. Both deletions eliminate enzyme activity of the second CP-like domain and appear to cause the misfolding of the protein. This greatly reduces the levels of the long forms of CPD protein but do not affect the levels of the short forms. Taken together, these findings suggest that lethal and viable svr alleles differ in which protein forms are affected. Flies that retain the short form are viable, whereas flies that are missing all forms of CPD do not survive past the early larval stages.
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Affiliation(s)
- Galyna Sidyelyeva
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, New York 10461
| | - Nicholas E Baker
- Department of Molecular Genetics, Albert Einstein College of Medicine, Bronx, New York 10461
| | - Lloyd D Fricker
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, New York 10461.
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Wegener C, Reinl T, Jänsch L, Predel R. Direct mass spectrometric peptide profiling and fragmentation of larval peptide hormone release sites in Drosophila melanogaster reveals tagma-specific peptide expression and differential processing. J Neurochem 2006; 96:1362-74. [PMID: 16441518 DOI: 10.1111/j.1471-4159.2005.03634.x] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Regulatory peptides represent a diverse group of messenger molecules. In insects, they are produced by endocrine cells as well as secretory neurones within the CNS. Many regulatory peptides are released as hormones into the haemolymph to regulate, for example, diuresis, heartbeat or ecdysis behaviour. Hormonal release of neuropeptides takes place at specialized organs, so-called neurohaemal organs. We have performed a mass spectrometric characterization of the peptide complement of the main neurohaemal organs and endocrine cells of the Drosophila melanogaster larva to gain insight into the hormonal communication possibilities of the fruit fly. Using matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) and MALDI-TOF-TOF tandem mass spectrometry, we detected 23 different peptides of which five were unpredicted by previous genome screenings. We also found a hitherto unknown peptide product of the capa gene in the ring gland and transverse nerves, suggesting that it might be released as hormone. Our results show that the peptidome of the neurohaemal organs is tagma-specific and does not change during metamorphosis. We also provide evidence for the first case of differential prohormone processing in Drosophila.
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Affiliation(s)
- Christian Wegener
- Emmy Noether Neuropeptide Group, Animal Physiology, Philipps-University, Marburg, Germany
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