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Vargas-Pinilla P, S Oliveira Fam B, Medina Tavares G, Lima T, Landau L, Paré P, de Cássia Aleixo Tostes R, Pissinatti A, Falótico T, Costa-Neto C, Maestri R, Bortolini MC. From molecular variations to behavioral adaptations: Unveiling adaptive epistasis in primate oxytocin system. AMERICAN JOURNAL OF BIOLOGICAL ANTHROPOLOGY 2024; 184:e24947. [PMID: 38783700 DOI: 10.1002/ajpa.24947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Revised: 04/12/2024] [Accepted: 04/24/2024] [Indexed: 05/25/2024]
Abstract
OBJECTIVE Our primary objective was to investigate the variability of oxytocin (OT) and the GAMEN binding motif within the LNPEP oxytocinase in primates. MATERIALS AND METHODS We sequenced the LNPEP segment encompassing the GAMEN motif in 34 Platyrrhini species, with 21 of them also sequenced for the OT gene. Our dataset was supplemented with primate sequences of LNPEP, OT, and the oxytocin receptor (OTR) sourced from public databases. Evolutionary analysis and coevolution predictions were made followed by the macroevolution analysis of relevant amino acids associated with phenotypic traits, such as mating systems, parental care, and litter size. To account for phylogenetic structure, we utilized two distinct statistical tests. Additionally, we calculated binding energies focusing on the interaction between Callithtrix jacchus VAMEN and Pro8OT. RESULTS We identified two novel motifs (AAMEN and VAMEN), challenging the current knowledge of motif conservation in placental mammals. Coevolution analysis demonstrated a correlation between GAMEN, AAMEN, and VAMEN and their corresponding OTs and OTRs. Callithrix jacchus exhibited a higher binding energy between VAMEN and Pro8OT than orthologous molecules found in humans (GAMEN and Leu8OT). DISCUSSION The coevolution of AAMEN and VAMEN with their corresponding OTs and OTRs suggests a functional relationship that could have contributed to specific reproductive and adaptive behaviors, including paternal care, social monogamy, and twin births, prominent traits in Cebidae species, such as marmosets and tamarins. Our findings underscore the coevolution of taxon-specific amino acids among the three studied molecules, shedding light on the oxytocinergic system as an adaptive epistatic repertoire in primates.
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Affiliation(s)
- Pedro Vargas-Pinilla
- Laboratory of Human and Molecular Evolution, Departamento de Genética, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
- Departamento de Farmacologia, Faculdade de Medicina, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Bibiana S Oliveira Fam
- Laboratory of Human and Molecular Evolution, Departamento de Genética, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
- Laboratório de Medicina Genômica, Centro de Pesquisa Experimental (CPE), Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil
| | - Gustavo Medina Tavares
- Laboratory of Human and Molecular Evolution, Departamento de Genética, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Thaynara Lima
- Laboratory of Human and Molecular Evolution, Departamento de Genética, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Luane Landau
- Laboratory of Human and Molecular Evolution, Departamento de Genética, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
- Department of Biological Sciences, University at Buffalo, Buffalo, New York, USA
| | - Pâmela Paré
- Laboratory of Human and Molecular Evolution, Departamento de Genética, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | | | | | - Tiago Falótico
- Escola de Artes, Ciências e Humanidades, Universidade de São Paulo, São Paulo, Brazil
| | - Cláudio Costa-Neto
- Departamento de Bioquímica e Imunologia, Faculdade de Medicina, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Renan Maestri
- Laboratório de Ecomorfologia e Macroevolução, Departamento de Ecologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Maria Cátira Bortolini
- Laboratory of Human and Molecular Evolution, Departamento de Genética, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
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Diel de Amorim M, Dong L, Byron M, Foster RA, Klein C, Saleh M, Saleh T, Card C. Characterization of serum and tissue oxytocinase and tissue oxytocin in the pregnant and non-pregnant mare. Sci Rep 2023; 13:4616. [PMID: 36944665 PMCID: PMC10030782 DOI: 10.1038/s41598-023-31540-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 03/14/2023] [Indexed: 03/23/2023] Open
Abstract
Oxytocin is a hormone with functions in: reproduction, maternal bonding, milk ejection, and feeding/social behavior, and is reported to be present in a variety of tissues. Our goal is to characterize oxytocin and leucyl and cystinyl aminopeptidase (LNPEP/oxytocinase), a key regulator of oxytocin in mares. We measured serum and tissue LNPEP by ELISA from ovulation (D0) until D21-22 in non-pregnant (n = 5) and pregnant mares (n = 6); and in periparturient and postpartum mares (n = 18). Placenta (n = 7) and homogenized tissue of diestrus mares (n = 6) were evaluated using protein determinations and LNPEP ELISAs. Identification of LNPEP and OXT protein in tissues was also performed via western blot, immunohistochemistry and liquid chromatography-mass spectrometry (LC-MS/MS). Furthermore, in situ hybridization was performed for LNPEP and OXT on endometrium, myometrium, pituitary and corpus luteum (CL). Serum LNPEP concentration were similar. Placental LNPEP U/mg protein was highest in the body and pregnant horn. The highest to lowest LNPEP U/mg protein by tissue were: myometrium > follicle wall > endometrium > kidney > CL > liver. Oxytocin was identified in the equine pituitary, CL and placenta and is likely to act in autocrine or paracrine manner, while LNPEP may act systemically and locally to regulate the availability of OXT.
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Affiliation(s)
- Mariana Diel de Amorim
- Department of Clinical Sciences, Cornell University, 930 Campus Rd, Ithaca, NY, 14853, USA.
| | - Lynn Dong
- Immunopathology Research and Development Laboratory, Department of Biomedical Sciences, Cornell University, 930 Campus Rd, Ithaca, NY, 14853, USA
- Translational Pathology, Bristol Myers Squibb, Route 206 and Provinceline Rd., Princeton, NJ, 08543, USA
| | - Michael Byron
- Department of Clinical Sciences, Cornell University, 930 Campus Rd, Ithaca, NY, 14853, USA
| | - Robert A Foster
- Department of Pathobiology, Ontario Veterinary College, University of Guelph, 50 Stone Road E., Guelph, ON, N1G 2W1, Canada
| | - Claudia Klein
- Department of Veterinary Clinical and Diagnostic Science, University of Calgary, 2500 University Drive NW, Calgary, AB, T2N 1N4, Canada
- Federal Research Institute for Animal Health, Institute of Farm Animal Genetics, Hoeltystr.10, 31535, Neustadt-Mariense, Germany
| | - Monique Saleh
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, 50 Stone Road E., Guelph, ON, N1G 2W1, Canada
| | - Tarek Saleh
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, 50 Stone Road E., Guelph, ON, N1G 2W1, Canada
| | - Claire Card
- Department of Large Animal Clinical Sciences, Western College of Veterinary Medicine, 52 Campus Drive, Saskatoon, SK, S7N 5B4, Canada.
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Diel de Amorim M, Bramer SA, Rajamanickam GD, Klein C, Card C. Endometrial and luteal gene expression of putative gene regulators of the equine maternal recognition of pregnancy. Anim Reprod Sci 2022; 245:107064. [DOI: 10.1016/j.anireprosci.2022.107064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2022] [Revised: 08/16/2022] [Accepted: 08/28/2022] [Indexed: 11/16/2022]
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Georgiadis D, Ziotopoulou A, Kaloumenou E, Lelis A, Papasava A. The Discovery of Insulin-Regulated Aminopeptidase (IRAP) Inhibitors: A Literature Review. Front Pharmacol 2020; 11:585838. [PMID: 33071797 PMCID: PMC7538644 DOI: 10.3389/fphar.2020.585838] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 08/24/2020] [Indexed: 12/15/2022] Open
Abstract
Insulin-Regulated Aminopeptidase (IRAP, EC 3.4.11.3) is a multi-tasking member of the M1 family of zinc aminopeptidases. Among its diverse biological functions, IRAP is a regulator of oxytocin levels during late stages of pregnancy, it affects cellular glucose uptake by trafficking of the glucose transporter type 4 and it mediates antigen cross-presentation by dendritic cells. Accumulating evidence show that pharmacological inhibition of IRAP may hold promise as a valid approach for the treatment of several pathological states such as memory disorders, neurodegenerative diseases, etc. Aiming to the investigation of physiological roles of IRAP and therapeutic potential of its regulation, intense research efforts have been dedicated to the discovery of small-molecule inhibitors. Moreover, reliable structure-activity relationships have been largely facilitated by recent crystal structures of IRAP and detailed computational studies. This review aims to summarize efforts of medicinal chemists toward the design and development of IRAP inhibitors, with special emphasis to factors affecting inhibitor selectivity.
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Affiliation(s)
- Dimitris Georgiadis
- Laboratory of Organic Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, Athens, Greece
| | - Angeliki Ziotopoulou
- Laboratory of Organic Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, Athens, Greece
| | - Eleni Kaloumenou
- Laboratory of Organic Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, Athens, Greece
| | - Angelos Lelis
- Laboratory of Organic Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, Athens, Greece
| | - Antonia Papasava
- Laboratory of Organic Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, Athens, Greece
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Vasopressin inactivation: Role of insulin-regulated aminopeptidase. VITAMINS AND HORMONES 2019; 113:101-128. [PMID: 32138946 DOI: 10.1016/bs.vh.2019.08.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The physiological importance of vasopressin inactivation has long been appreciated, but the mechanisms and potential pathophysiologic roles of this process remain active subjects of research. Human Placental Leucine Aminopeptidase (P-LAP, encoded by the LNPEP gene) is an important determinant of vasopressinase activity during pregnancy and is associated with gestational diabetes insipidus and preeclampsia. Insulin-Regulated Aminopeptidase (IRAP), the rodent homologue of P-LAP, is coregulated with the insulin-responsive glucose transporter, GLUT4, in adipose and muscle cells. Recently, the Tether containing a UBX domain for GLUT4 (TUG) protein was shown to mediate the coordinated regulation of water and glucose homeostasis. TUG sequesters IRAP and GLUT4 intracellularly in the absence of insulin. Insulin and other stimuli cause the proteolytic cleavage of TUG to mobilize these proteins to the cell surface, where IRAP acts to terminate the activity of circulating vasopressin. Intriguingly, genetic variation in LNPEP is associated with the vasopressin response and mortality during sepsis, and increased copeptin, a marker of vasopressin secretion, is associated with cardiovascular and metabolic disease. We propose that in the setting of insulin resistance in muscle, increased cell-surface IRAP and accelerated vasopressin degradation cause a compensatory increase in vasopressin secretion. The increased vasopressin concentrations present at the kidneys then contribute to hypertension in the metabolic syndrome. Further analyses of metabolism and of vasopressin and copeptin may yield novel insights into a unified pathophysiologic mechanism linking insulin resistance and hypertension, and potentially other components of the metabolic syndrome, in humans.
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Ding C, Leow MKS, Magkos F. Oxytocin in metabolic homeostasis: implications for obesity and diabetes management. Obes Rev 2019; 20:22-40. [PMID: 30253045 PMCID: PMC7888317 DOI: 10.1111/obr.12757] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Revised: 07/25/2018] [Accepted: 07/25/2018] [Indexed: 12/20/2022]
Abstract
Oxytocin was once understood solely as a neuropeptide with a central role in social bonding, reproduction, parturition, lactation and appetite regulation. Recent evidence indicates that oxytocin enhances glucose uptake and lipid utilization in adipose tissue and skeletal muscle, suggesting that dysfunction of the oxytocin system could underlie the pathogenesis of insulin resistance and dyslipidaemia. Murine studies revealed that deficiencies in oxytocin signalling and oxytocin receptor expression lead to obesity despite normal food intake, motor activity and increased leptin levels. In addition, plasma oxytocin concentration is notably lower in obese individuals with diabetes, which may suggest an involvement of the oxytocin system in the pathogenesis of cardiometabolic disease. More recently, small scale studies demonstrated that intranasal administration of oxytocin was associated with significant weight loss as well as improvements in insulin sensitivity and pancreatic β-cell responsivity in human subjects. The multi-pronged effects of oxytocin signalling on improving peripheral insulin sensitivity, pancreatic function and lipid homeostasis strongly suggest a role for this system as a therapeutic target in obesity and diabetes management. The complexity of obesity aetiology and the pathogenesis of obesity-related metabolic complications underscore the need for a systems approach to better understand the role of oxytocin in metabolic function.
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Affiliation(s)
- C Ding
- Clinical Nutrition Research Centre (CNRC), Singapore Institute for Clinical Sciences (SICS), Agency for Science, Technology and Research (A*STAR) and National University Health System, Singapore
| | - M K-S Leow
- Clinical Nutrition Research Centre (CNRC), Singapore Institute for Clinical Sciences (SICS), Agency for Science, Technology and Research (A*STAR) and National University Health System, Singapore.,Department of Endocrinology, Tan Tock Seng Hospital, Singapore.,Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School, Singapore.,Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
| | - F Magkos
- Clinical Nutrition Research Centre (CNRC), Singapore Institute for Clinical Sciences (SICS), Agency for Science, Technology and Research (A*STAR) and National University Health System, Singapore.,Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore (NUS), Singapore
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Elkins EA, Walti KA, Newberry KE, Lema SC. Identification of an oxytocinase/vasopressinase-like leucyl-cystinyl aminopeptidase (LNPEP) in teleost fish and evidence for hypothalamic mRNA expression linked to behavioral social status. Gen Comp Endocrinol 2017; 250:58-69. [PMID: 28596078 DOI: 10.1016/j.ygcen.2017.06.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Revised: 06/03/2017] [Accepted: 06/04/2017] [Indexed: 02/06/2023]
Abstract
The vasotocin/vasopressin and isotocin/mesotocin/oxytocin family of nonapeptides regulate social behaviors and physiological functions associated with reproductive physiology and osmotic balance. While experimental and correlative studies provide evidence for these nonapeptides as modulators of behavior across all classes of vertebrates, mechanisms for nonapeptide inactivation in regulating these functions have been largely overlooked. Leucyl-cystinyl aminopeptidase (LNPEP) - also known as vasopressinase, oxytocinase, placental leucine aminopeptidase (P-LAP), and insulin-regulated aminopeptidase (IRAP) - is a membrane-bound zinc-dependent metalloexopeptidase enzyme that inactivates vasopressin, oxytocin, and select other cyclic polypeptides. In humans, LNPEP plays a key role in the clearance of oxytocin during pregnancy. However, the evolutionary diversity, expression distribution, and functional roles of LNPEP remain unresolved for other vertebrates. Here, we isolated and sequenced a full-length cDNA encoding a LNPEP-like polypeptide of 1033 amino acids from the ovarian tissue of Amargosa pupfish, Cyprinodon nevadensis. This deduced polypeptide exhibited high amino acid identity to human LNPEP both in the protein's active domain that includes the peptide binding site and zinc cofactor binding motif (53.1% identity), and in an intracellular region that distinguishes LNPEP from other aminopeptidases (70.3% identity). Transcripts encoding this LNPEP enzyme (lnpep) were detected at highest relative abundance in the gonads, hypothalamus, forebrain, optic tectum, gill and skeletal muscle of adult pupfish. Further evaluation of lnpep transcript abundance in the brain of sexually-mature pupfish revealed that lnpep mRNAs were elevated in the hypothalamus of socially subordinate females and males, and at lower abundance in the telencephalon of socially dominant males compared to dominant females. These findings provide evidence of an association between behavioral social status and hypothalamic lnpep transcript abundance and suggest that variation in the rate of VT/IT peptide inactivation by LNPEP may be a contributing component in the mechanism whereby nonapeptides regulate social behavior.
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Affiliation(s)
- Emma A Elkins
- Biological Sciences Department, Center for Coastal Marine Sciences, California Polytechnic State University, San Luis Obispo, CA 93407, USA
| | - Kayla A Walti
- Biological Sciences Department, Center for Coastal Marine Sciences, California Polytechnic State University, San Luis Obispo, CA 93407, USA
| | - Kathryn E Newberry
- Biological Sciences Department, Center for Coastal Marine Sciences, California Polytechnic State University, San Luis Obispo, CA 93407, USA
| | - Sean C Lema
- Biological Sciences Department, Center for Coastal Marine Sciences, California Polytechnic State University, San Luis Obispo, CA 93407, USA.
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Kobayashi H, Nomura S, Mitsui T, Ito T, Kuno N, Ohno Y, Kadomatsu K, Muramatsu T, Nagasaka T, Mizutani S. Tissue Distribution of Placental Leucine Aminopeptidase/Oxytocinase During Mouse Pregnancy. J Histochem Cytochem 2016; 52:113-21. [PMID: 14688222 DOI: 10.1177/002215540405200111] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Placental leucine aminopeptidase (P-LAP), also called oxytocinase, is an enzyme responsible for hydrolyzing oxytocin. This enzyme is identical to cystine aminopeptidase. We examined the tissue distribution of P-LAP in normal adult mice and also in mothers and fetuses during mouse pregnancy using immunohistochemical (IHC) analysis. P-LAP-immunoreactive protein was expressed in various organs in a cell- and gestational stage-dependent manner. In the kidney, P-LAP was located in distal and collecting tubules but not in proximal tubules. The islet of Langerhans in the maternal pancreas stained positively for P-LAP in the periphery in early gestation. This staining pattern changed so that both the periphery and inner cells were positive during mid-gestation and finally only inner cells were positive in late gestation. Among the hematopoietic cells in the fetal liver, only megakaryocytes showed strong expression of P-LAP. The staining intensity increased with gestation on the apical surface of trophoblasts in the placental labyrinth. These data demonstrate that P-LAP is present in a variety of tissues, and its presence is affected by pregnancy and fetal development. Therefore, P-LAP may play a significant role in various physiological processes in non-pregnant, pregnant, and fetal mice.
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Affiliation(s)
- Honami Kobayashi
- Departments of Obstetrics and Gynecology, Nagoya University Graduate School of Medicine, Nagoya, Japan
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Tobin VA, Arechaga G, Brunton PJ, Russell JA, Leng G, Ludwig M, Douglas AJ. Oxytocinase in the female rat hypothalamus: a novel mechanism controlling oxytocin neurones during lactation. J Neuroendocrinol 2014; 26:205-16. [PMID: 24612105 DOI: 10.1111/jne.12141] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Revised: 02/11/2014] [Accepted: 02/22/2014] [Indexed: 01/09/2023]
Abstract
In addition to its peripheral actions, oxytocin released within the brain is important for birth and essential for milk ejection. The oxytocinase enzyme (placental leucine aminopeptidase; P-LAP) is expressed both peripherally and centrally. P-LAP controls oxytocin degradation in the uterus, placenta and plasma during pregnancy, although its role in the hypothalamus is unclear. We investigated P-LAP expression and activity in the hypothalamus in virgin, pregnant and lactating rats, as well as its role in vivo during the milk-ejection reflex. P-LAP mRNA and protein were expressed in magnocellular neurones of the supraoptic (SON) and paraventricular (PVN) nuclei. Oxytocin neurones co-expressed P-LAP without strong subcellular co-localisation of oxytocin and P-LAP, indicating that they are packaged in separate vesicles. Examination of the intracellular distribution of oxytocin and P-LAP showed a redistribution of P-LAP to within 1 μm of the plasma membrane in the somata of oxytocin neurones during lactation. Both P-LAP mRNA expression and hypothalamic leucyl/cystinyl aminopeptidase activity in the soluble fraction were higher during lactation than in late pregnant or virgin states. Inhibition of central enzyme activity by i.c.v. injection of amastatin in anaesthetised suckling mothers increased the frequency of reflex milk ejections. Because hypothalamic P-LAP expression and activity increase in lactation, and the prevention of its action mimics central oxytocin administration, we conclude that P-LAP regulates auto-excitatory oxytocin actions during the suckling-induced milk-ejection reflex.
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Affiliation(s)
- V A Tobin
- Centre for Integrative Physiology, College of Medicine and Veterinary Medicine, University of Edinburgh, Edinburgh, UK
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Chow LH, Tao PL, Chen JC, Liao RM, Chang EP, Huang EYK. A possible correlation between oxytocin-induced and angiotensin IV-induced anti-hyperalgesia at the spinal level in rats. Peptides 2013; 39:21-8. [PMID: 23142109 DOI: 10.1016/j.peptides.2012.10.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2012] [Revised: 10/29/2012] [Accepted: 10/29/2012] [Indexed: 11/29/2022]
Abstract
In our previous study, we showed that intrathecal (i.t.) administration of angiotensin IV (Ang IV), an insulin-regulated aminopeptidase (IRAP) inhibitor, attenuated inflammatory hyperalgesia in rats. Using the plantar test in rats with carrageenan-induced paw inflammation, we investigated the possible mechanism(s) of this effect. Because i.t. oxytocin was reported to produce a dose-dependent anti-hyperalgesia in rats with inflammation, we speculate that there is a possible correlation between oxytocin-induced and Ang IV-induced anti-hyperalgesia. Using i.t. co-administered atosiban (oxytocin receptor antagonist), the anti-hyperalgesia by Ang IV was completely abolished. This indicated that oxytocin could be the major IRAP substrate responsible for the anti-hyperalgesia by Ang IV. When Ang IV was co-administered with a low dose of oxytocin, there was a significant enhancing effect of Ang IV on oxytocin-induced anti-hyperalgesia. In recent reports, electrical stimulation on the paraventricular hypothalamic nucleus (PVN) was proved to increase oxytocin release at the spinal cord. Our results also showed that Ang IV could prolong the anti-hyperalgesia induced by PVN stimulation. This suggests a possible protective effect of Ang IV on endogenous oxytocin degradation/dysfunctioning. Moreover, we examined the local effect of intraplantarly injected Ang IV in the same model. Our results showed no effect of local Ang IV on hyperalgesia and paw edema, indicating that Ang IV may not regulate the peripheral inflammatory process. Overall, our study suggests that Ang IV may act through the inhibition of the activity of IRAP to reduce the degradation of oxytocin at the spinal cord, thereby leading to anti-hyperalgesia in rats with inflammation.
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Affiliation(s)
- Lok-Hi Chow
- Department of Pharmacology, National Defense Medical Center, Taipei, Taiwan
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Discovery of inhibitors of insulin-regulated aminopeptidase as cognitive enhancers. Int J Hypertens 2012; 2012:789671. [PMID: 23304452 PMCID: PMC3529497 DOI: 10.1155/2012/789671] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2012] [Accepted: 10/19/2012] [Indexed: 12/20/2022] Open
Abstract
The hexapeptide angiotensin IV (Ang IV) is a metabolite of angiotensin II (Ang II) and plays a central role in the brain. It was reported more than two decades ago that intracerebroventricular injection of Ang IV improved memory and learning in the rat. Several hypotheses have been put forward to explain the positive effects of Ang IV and related analogues on cognition. It has been proposed that the insulin-regulated aminopeptidase (IRAP) is the main target of Ang IV. This paper discusses progress in the discovery of inhibitors of IRAP as potential enhancers of cognitive functions. Very potent inhibitors of the protease have been synthesised, but pharmacokinetic issues (including problems associated with crossing the blood-brain barrier) remain to be solved. The paper also briefly presents an overview of the status in the discovery of inhibitors of ACE and renin, and of AT1R antagonists and AT2R agonists, in order to enable other discovery processes within the RAS system to be compared. The paper focuses on the relationship between binding affinities/inhibition capacity and the structures of the ligands that interact with the target proteins.
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Cheng BC, Tao PL, Cheng YY, Huang EYK. LVV-hemorphin 7 and angiotensin IV in correlation with antinociception and anti-thermal hyperalgesia in rats. Peptides 2012; 36:9-16. [PMID: 22484286 DOI: 10.1016/j.peptides.2012.03.019] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2012] [Revised: 03/20/2012] [Accepted: 03/20/2012] [Indexed: 12/01/2022]
Abstract
Hemorphins, a family of atypical endogenous opioid peptides, are produced by the cleavage of hemoglobin β-chain. Hemorphins were proved to bind to the μ-opioid receptors (agonist) and angiotensin IV receptors (insulin-regulated aminopeptidase; IRAP) (inhibitor). Among the hemorphins, LVV-hemorphin-7 (LVV-H7) was found to be abundant and with a longer half life in the CNS. Using intrathecal and intracerebroventricular injections, LVV-H7 and angiotensin IV were given to the rats, which were then subjected to the plantar test and the tail-flick test. Our results showed that LVV-H7 attenuated carrageenan-induced hyperalgesia at the spinal level, which could not be reversed by the co-administration of naloxone. At the supraspinal level, LVV-H7 also produced a significant anti-hyperalgesia effect but with a lower extent. Angiotensin IV showed a similar anti-hyperalgesia effect at the spinal level, but had no effect at the supraspinal level. In the tail-flick test and paw edema test, both peptides showed no effect. These results suggest that LVV-H7 mainly exert the anti-hyperalgesia effect at the spinal level, possibly through IRAP but not μ-opioid receptors. In addition, we observed the expression of IRAP in the CNS of animals with/without carrageenan-induced hyperalgesia. Our results showed a significant expression of IRAP in the spinal cord of rats. However, there was no significant quantitative change of IRAP after the development of hyperalgesia. The serum level of LVV-H7 was also found to be with no change caused by hyperalgesia. These results indicated that the endogenous LVV-H7 and IRAP may not regulate the severity of hyperalgesia through a quantitative change.
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Affiliation(s)
- Bor-Chih Cheng
- Department of Surgery, Chi Mei Medical Center, Tainan, Taiwan, ROC
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van Munster M, le Gleuher M, Pauchet Y, Augustin S, Courtin C, Amichot M, Ffrench-Constant RH, Pauron D. Molecular characterization of three genes encoding aminopeptidases N in the poplar leaf beetle Chrysomela tremulae. INSECT MOLECULAR BIOLOGY 2011; 20:267-278. [PMID: 21205278 DOI: 10.1111/j.1365-2583.2010.01067.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Three genes encoding proteins showing sequence similarity and features typical of insect APNs were characterized in C. tremulae and designed as CtAPN1, CtAPN2 and CtAPN3. Expression analysis of the three C. tremulae APN genes showed that CtAPN2 transcript is more abundant in the fat body, whereas both CtAPN1 and CtAPN3 are specifically expressed in the midgut. Despite a similar genomic organization, lepidopteran and coleopteran APNs are phylogenetically distant, suggesting that APN gene duplication events occurred after these two insect orders split. Sequence and expression comparisons of CtAPN1, CtAPN2 and CtAPN3 cDNAs in a C. tremulae Bacillus thuringiensis (Bt)-susceptible and in a Bt-resistant strain did not show any polymorphism at the amino acid level or difference at the transcription level.
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Affiliation(s)
- M van Munster
- INRA, UMR 1301 Interactions Biotiques et Santé Végétale, Sophia Antipolis, France.
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Vaiyapuri S, Wagstaff SC, Watson KA, Harrison RA, Gibbins JM, Hutchinson EG. Purification and functional characterisation of rhiminopeptidase A, a novel aminopeptidase from the venom of Bitis gabonica rhinoceros. PLoS Negl Trop Dis 2010; 4:e796. [PMID: 20706583 PMCID: PMC2919393 DOI: 10.1371/journal.pntd.0000796] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2010] [Accepted: 07/14/2010] [Indexed: 11/18/2022] Open
Abstract
Background Snake bite is a major neglected public health issue within poor communities living in the rural areas of several countries throughout the world. An estimated 2.5 million people are bitten by snakes each year and the cost and lack of efficacy of current anti-venom therapy, together with the lack of detailed knowledge about toxic components of venom and their modes of action, and the unavailability of treatments in rural areas mean that annually there are around 125,000 deaths worldwide. In order to develop cheaper and more effective therapeutics, the toxic components of snake venom and their modes of action need to be clearly understood. One particularly poorly understood component of snake venom is aminopeptidases. These are exo-metalloproteases, which, in mammals, are involved in important physiological functions such as the maintenance of blood pressure and brain function. Although aminopeptidase activities have been reported in some snake venoms, no detailed analysis of any individual snake venom aminopeptidases has been performed so far. As is the case for mammals, snake venom aminopeptidases may also play important roles in altering the physiological functions of victims during envenomation. In order to further understand this important group of snake venom enzymes we have isolated, functionally characterised and analysed the sequence-structure relationships of an aminopeptidase from the venom of the large, highly venomous West African gaboon viper, Bitis gabonica rhinoceros. Methodology and Principal Findings The venom of B. g. rhinoceros was fractionated by size exclusion chromatography and fractions with aminopeptidase activities were isolated. Fractions with aminopeptidase activities showed a pure protein with a molecular weight of 150 kDa on SDS-PAGE. In the absence of calcium, this purified protein had broad aminopeptidase activities against acidic, basic and neutral amino acids but in the presence of calcium, it had only acidic aminopeptidase activity (APA). Together with the functional data, mass spectrometry analysis of the purified protein confirmed this as an aminopeptidase A and thus this has been named as rhiminopeptidase A. The complete gene sequence of rhiminopeptidase A was obtained by sequencing the PCR amplified aminopeptidase A gene from the venom gland cDNA of B. g. rhinoceros. The gene codes for a predicted protein of 955 amino acids (110 kDa), which contains the key amino acids necessary for functioning as an aminopeptidase A. A structural model of rhiminopeptidase A shows the structure to consist of 4 domains: an N-terminal saddle-shaped β domain, a mixed α and β catalytic domain, a β-sandwich domain and a C-terminal α helical domain. Conclusions This study describes the discovery and characterisation of a novel aminopeptidase A from the venom of B. g. rhinoceros and highlights its potential biological importance. Similar to mammalian aminopeptidases, rhiminopeptidase A might be capable of playing roles in altering the blood pressure and brain function of victims. Furthermore, it could have additional effects on the biological functions of other host proteins by cleaving their N-terminal amino acids. This study points towards the importance of complete analysis of individual components of snake venom in order to develop effective therapies for snake bites. Snake bite is a major neglected public health issue causing an estimated 125,000 deaths each year, predominantly within poor communities living in rural areas of countries in South East Asia and Africa. Current treatments for snake bites are costly and have limited effectiveness, thus there is a need to develop novel therapeutics. In order to do this the toxic components of snake venom need to be clearly understood. Enzymes called aminopeptidases have been noticed in several snake venoms, but their functions have not been characterised. Related enzymes are also present in mammals, where they are involved in the maintenance of blood pressure and brain function. To further understand this important group of enzymes within snake venom we have purified and analysed the function and structure of an aminopeptidase from the venom of the West African gaboon viper. Our results suggest that this enzyme could also affect the maintenance of blood pressure and brain function in victims of snake bites. Along with other snake venom components, aminopeptidases might be a potential therapeutic target for developing novel treatments for snake bites.
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Affiliation(s)
- Sakthivel Vaiyapuri
- School of Biological Sciences, University of Reading, Whiteknights, Reading, United Kingdom
| | - Simon C. Wagstaff
- Alistair Reid Venom Research Unit, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, United Kingdom
| | - Kimberley A. Watson
- School of Biological Sciences, University of Reading, Whiteknights, Reading, United Kingdom
| | - Robert A. Harrison
- Alistair Reid Venom Research Unit, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, United Kingdom
| | - Jonathan M. Gibbins
- School of Biological Sciences, University of Reading, Whiteknights, Reading, United Kingdom
- Blood Transfusion Research Group, King Saud University, Riyadh, Saudi Arabia
| | - E. Gail Hutchinson
- School of Biological Sciences, University of Reading, Whiteknights, Reading, United Kingdom
- * E-mail:
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15
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Kawai M, Araragi K, Shimizu Y, Hara Y. Identification of placental leucine aminopeptidase and triton-slowed aminopeptidase N in serum of pregnant women. Clin Chim Acta 2008; 400:37-41. [PMID: 18996364 DOI: 10.1016/j.cca.2008.10.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2008] [Revised: 10/02/2008] [Accepted: 10/03/2008] [Indexed: 11/24/2022]
Abstract
BACKGROUND Previously, we found characteristic triton-slowed bands of aminopeptidase N (APN) in cholestatic serum by triton-polyacrylamide gel electrophoresis (triton-PAGE) [Makoto Kawai, Yukichi Hara, Triton-polyacrylamide gel electrophoresis and leucine aminopeptidase activity staining detect Triton-slowed bands including high-molecular-mass aminopeptidase N (CD13) isoform in cholestatic patient sera. Clin Chim Acta 2006; 364:188-195]. METHODS Sera from 14 normal pregnant women were electrophoresed on polyacrylamide gel containing 0.02 l/l triton (triton-PAGE) or a 0-0.02 l/l horizontal gradient of triton (gradient-triton-PAGE), and stained with leucine-beta-naphthylamide. Some samples were pretreated with a monoclonal APN antibody or rabbit anti-placental leucine aminopeptidase (PLAP) serum. The stained bands were eluted from the gel, treated with N- and O-glycosidase, and analyzed by Western blotting with rabbit anti-APN or anti-PLAP serum. RESULTS Triton-PAGE clearly differentiated 5 LAP activity bands (1-5 from the front). Gradient-triton-PAGE revealed that bands 4-5 were slowed by triton (triton-slowed bands) much more than bands 1-3. Triton-PAGE of antibody-treated serum showed that bands 1, 2, 4, and 5 are mainly APN and that band 3 is PLAP. The molecular mass of PLAP was about 130-140 kDa before treatment with glycosidases but 100 kDa after. Triton-PAGE detected PLAP in 13 and triton-slowed APN in 4 of the 14 women. CONCLUSIONS Triton-PAGE differentiates PLAP from APN. Triton-slowed APN as well as PLAP is present in the serum of pregnant women.
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Affiliation(s)
- Makoto Kawai
- Department of Gastroenterology, Tokyo Kyosai Hospital, Tokyo, Japan.
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16
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Zhang R, Hua G, Andacht TM, Adang MJ. A 106-kDa aminopeptidase is a putative receptor for Bacillus thuringiensis Cry11Ba toxin in the mosquito Anopheles gambiae. Biochemistry 2008; 47:11263-72. [PMID: 18826260 DOI: 10.1021/bi801181g] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Bacillus thuringiensis (Bt) insecticidal toxins bind to receptors on midgut epithelial cells of susceptible insects, and binding triggers biochemical events that lead to insect mortality. Recently, a 100-kDa aminopeptidase N (APN) was isolated from brush border membrane vesicles (BBMV) of Anopheles quadrimaculatus and shown to bind Cry11Ba toxin with surface plasmon resonance (SPR) detection [Abdullah et al. (2006) BMC Biochem. 7, 16]. In our study, a 106-kDa APN, called AgAPN2, released by phosphatidylinositol-specific phospholipase C (PI-PLC) from Anopheles gambiae BBMV was extracted by Cry11Ba bound to beads. The AgAPN2 cDNA was cloned, and analysis of the predicted AgAPN2 protein revealed a zinc-binding motif (HEIAH), three potential N-glycosylation sites, and a predicted glycosylphosphatidylinositol (GPI) anchor site. Immunohistochemistry localized AgAPN2 to the microvilli of the posterior midgut. A 70-kDa fragment of the 106-kDa APN was expressed in Escherichia coli. When purified, it competitively displaced 125I-Cry11Ba binding to An. gambiae BBMV and bound Cry11Ba on dot blot and microtiter plate binding assays with a calculated K d of 6.4 nM. Notably, this truncated peptide inhibited Cry11Ba toxicity to An. gambiae larvae. These results are evidence that the 106-kDa GPI-anchored APN is a specific binding protein, and a putative midgut receptor, for Bt Cry11Ba toxin.
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Affiliation(s)
- Rui Zhang
- Department of Entomology and Biochemistry, University of Georgia, Athens, Georgia 30602-2603, USA
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17
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Lukaszuk A, Demaegdt H, Szemenyei E, Tóth G, Tymecka D, Misicka A, Karoyan P, Vanderheyden P, Vauquelin G, Tourwé D. β-Homo-amino Acid Scan of Angiotensin IV. J Med Chem 2008; 51:2291-6. [DOI: 10.1021/jm701490g] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Aneta Lukaszuk
- Department of Organic Chemistry, Department of Molecular and Biochemical Pharmacology, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussel, Belgium, Biological Research Center, Institute of Biochemistry, Temesvari krt. 62, 6726 Szeged, Hungary, Faculty of Chemistry, Warsaw University, Pasteura 1, 02-093 Warsaw, Poland, Medical Research Centre, Polish Academy of Sciences, Pawinskiego 5, 02-106 Warsaw, Poland, and CNRS/UMR 7613, Université Pierre & Marie Curie, Place Jussieu 4, Paris, France
| | - Heidi Demaegdt
- Department of Organic Chemistry, Department of Molecular and Biochemical Pharmacology, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussel, Belgium, Biological Research Center, Institute of Biochemistry, Temesvari krt. 62, 6726 Szeged, Hungary, Faculty of Chemistry, Warsaw University, Pasteura 1, 02-093 Warsaw, Poland, Medical Research Centre, Polish Academy of Sciences, Pawinskiego 5, 02-106 Warsaw, Poland, and CNRS/UMR 7613, Université Pierre & Marie Curie, Place Jussieu 4, Paris, France
| | - Erzsebet Szemenyei
- Department of Organic Chemistry, Department of Molecular and Biochemical Pharmacology, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussel, Belgium, Biological Research Center, Institute of Biochemistry, Temesvari krt. 62, 6726 Szeged, Hungary, Faculty of Chemistry, Warsaw University, Pasteura 1, 02-093 Warsaw, Poland, Medical Research Centre, Polish Academy of Sciences, Pawinskiego 5, 02-106 Warsaw, Poland, and CNRS/UMR 7613, Université Pierre & Marie Curie, Place Jussieu 4, Paris, France
| | - Géza Tóth
- Department of Organic Chemistry, Department of Molecular and Biochemical Pharmacology, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussel, Belgium, Biological Research Center, Institute of Biochemistry, Temesvari krt. 62, 6726 Szeged, Hungary, Faculty of Chemistry, Warsaw University, Pasteura 1, 02-093 Warsaw, Poland, Medical Research Centre, Polish Academy of Sciences, Pawinskiego 5, 02-106 Warsaw, Poland, and CNRS/UMR 7613, Université Pierre & Marie Curie, Place Jussieu 4, Paris, France
| | - Dagmara Tymecka
- Department of Organic Chemistry, Department of Molecular and Biochemical Pharmacology, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussel, Belgium, Biological Research Center, Institute of Biochemistry, Temesvari krt. 62, 6726 Szeged, Hungary, Faculty of Chemistry, Warsaw University, Pasteura 1, 02-093 Warsaw, Poland, Medical Research Centre, Polish Academy of Sciences, Pawinskiego 5, 02-106 Warsaw, Poland, and CNRS/UMR 7613, Université Pierre & Marie Curie, Place Jussieu 4, Paris, France
| | - Aleksandra Misicka
- Department of Organic Chemistry, Department of Molecular and Biochemical Pharmacology, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussel, Belgium, Biological Research Center, Institute of Biochemistry, Temesvari krt. 62, 6726 Szeged, Hungary, Faculty of Chemistry, Warsaw University, Pasteura 1, 02-093 Warsaw, Poland, Medical Research Centre, Polish Academy of Sciences, Pawinskiego 5, 02-106 Warsaw, Poland, and CNRS/UMR 7613, Université Pierre & Marie Curie, Place Jussieu 4, Paris, France
| | - Philippe Karoyan
- Department of Organic Chemistry, Department of Molecular and Biochemical Pharmacology, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussel, Belgium, Biological Research Center, Institute of Biochemistry, Temesvari krt. 62, 6726 Szeged, Hungary, Faculty of Chemistry, Warsaw University, Pasteura 1, 02-093 Warsaw, Poland, Medical Research Centre, Polish Academy of Sciences, Pawinskiego 5, 02-106 Warsaw, Poland, and CNRS/UMR 7613, Université Pierre & Marie Curie, Place Jussieu 4, Paris, France
| | - Patrick Vanderheyden
- Department of Organic Chemistry, Department of Molecular and Biochemical Pharmacology, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussel, Belgium, Biological Research Center, Institute of Biochemistry, Temesvari krt. 62, 6726 Szeged, Hungary, Faculty of Chemistry, Warsaw University, Pasteura 1, 02-093 Warsaw, Poland, Medical Research Centre, Polish Academy of Sciences, Pawinskiego 5, 02-106 Warsaw, Poland, and CNRS/UMR 7613, Université Pierre & Marie Curie, Place Jussieu 4, Paris, France
| | - Georges Vauquelin
- Department of Organic Chemistry, Department of Molecular and Biochemical Pharmacology, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussel, Belgium, Biological Research Center, Institute of Biochemistry, Temesvari krt. 62, 6726 Szeged, Hungary, Faculty of Chemistry, Warsaw University, Pasteura 1, 02-093 Warsaw, Poland, Medical Research Centre, Polish Academy of Sciences, Pawinskiego 5, 02-106 Warsaw, Poland, and CNRS/UMR 7613, Université Pierre & Marie Curie, Place Jussieu 4, Paris, France
| | - Dirk Tourwé
- Department of Organic Chemistry, Department of Molecular and Biochemical Pharmacology, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussel, Belgium, Biological Research Center, Institute of Biochemistry, Temesvari krt. 62, 6726 Szeged, Hungary, Faculty of Chemistry, Warsaw University, Pasteura 1, 02-093 Warsaw, Poland, Medical Research Centre, Polish Academy of Sciences, Pawinskiego 5, 02-106 Warsaw, Poland, and CNRS/UMR 7613, Université Pierre & Marie Curie, Place Jussieu 4, Paris, France
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Involvement of insulin-regulated aminopeptidase in the effects of the renin–angiotensin fragment angiotensin IV: a review. Heart Fail Rev 2007; 13:321-37. [DOI: 10.1007/s10741-007-9062-x] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2007] [Accepted: 10/16/2007] [Indexed: 10/22/2022]
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Albiston AL, Peck GR, Yeatman HR, Fernando R, Ye S, Chai SY. Therapeutic targeting of insulin-regulated aminopeptidase: heads and tails? Pharmacol Ther 2007; 116:417-27. [PMID: 17900701 DOI: 10.1016/j.pharmthera.2007.07.006] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2007] [Accepted: 07/30/2007] [Indexed: 10/22/2022]
Abstract
Insulin-regulated aminopeptidase, IRAP, is an abundant protein that was initially cloned from a rat epididymal fat pad cDNA library as a marker protein for specialized vesicles containing the insulin-responsive glucose transporter GLUT4, wherein it is thought to participate in the tethering and trafficking of GLUT4 vesicles. The same protein was independently cloned from human placental cDNA library as oxytocinase and is proposed to have a primary role in the regulation of circulating oxytocin (OXY) during the later stages of pregnancy. More recently, IRAP was identified as the specific binding site for angiotensin IV, and we propose that it mediates the memory-enhancing effects of the peptide. This protein appears to have multiple physiological roles that are tissue- and domain-specific; thus the protein can be specifically targeted for treating different clinical conditions.
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Affiliation(s)
- Anthony L Albiston
- Howard Florey Institute of Experimental Physiology and Medicine, University of Melbourne, Parkville, Victoria 3010, Australia
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20
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Fyfe JC, Menotti-Raymond M, David VA, Brichta L, Schäffer AA, Agarwala R, Murphy WJ, Wedemeyer WJ, Gregory BL, Buzzell BG, Drummond MC, Wirth B, O'Brien SJ. An approximately 140-kb deletion associated with feline spinal muscular atrophy implies an essential LIX1 function for motor neuron survival. Genome Res 2006; 16:1084-90. [PMID: 16899656 PMCID: PMC1557767 DOI: 10.1101/gr.5268806] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The leading genetic cause of infant mortality is spinal muscular atrophy (SMA), a clinically and genetically heterogeneous group of disorders. Previously we described a domestic cat model of autosomal recessive, juvenile-onset SMA similar to human SMA type III. Here we report results of a whole-genome scan for linkage in the feline SMA pedigree using recently developed species-specific and comparative mapping resources. We identified a novel SMA gene candidate, LIX1, in an approximately140-kb deletion on feline chromosome A1q in a region of conserved synteny to human chromosome 5q15. Though LIX1 function is unknown, the predicted secondary structure is compatible with a role in RNA metabolism. LIX1 expression is largely restricted to the central nervous system, primarily in spinal motor neurons, thus offering explanation of the tissue restriction of pathology in feline SMA. An exon sequence screen of 25 human SMA cases, not otherwise explicable by mutations at the SMN1 locus, failed to identify comparable LIX1 mutations. Nonetheless, a LIX1-associated etiology in feline SMA implicates a previously undetected mechanism of motor neuron maintenance and mandates consideration of LIX1 as a candidate gene in human SMA when SMN1 mutations are not found.
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Affiliation(s)
- John C Fyfe
- Laboratory of Comparative Medical Genetics, Department of Microbiology & Molecular Genetics, College of Veterinary Medicine, Michigan State University, East Lansing, Michigan 48824, USA.
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21
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Axén A, Lindeberg G, Demaegdt H, Vauquelin G, Karlén A, Hallberg M. Cyclic insulin-regulated aminopeptidase (IRAP)/AT4 receptor ligands. J Pept Sci 2006; 12:705-13. [PMID: 16967438 DOI: 10.1002/psc.782] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The angiotensin IV receptor (AT4 receptor) is the insulin-regulated aminopeptidase enzyme (IRAP, EC 3.4.11.3). This membrane-spanning enzyme belongs to the M1 family of zinc-dependent metallo-peptidases. It has been proposed that AT4 receptor ligands exert their physiological effects by binding to the active site of IRAP and thereby inhibiting the catalytic activity of the enzyme. The biological activity of a large series of linear angiotensin IV analogs was previously disclosed. Herein, the synthesis and biological evaluation of a series of angiotensin IV analogs, encompassing macrocyclic ring systems of different sizes, are presented. It is demonstrated that disulfide cyclizations of angiotensin IV can deliver ligands with high IRAP/AT4 receptor affinity. One ligand, with an 11-membered ring system (4), inhibited human IRAP and aminopeptidase N (AP-N) activity with similar potency as angiotensin IV but was considerably more stable than angiotensin IV toward enzymatic degradation. The compound provides a promising starting point for further optimization toward more drug-like derivatives. The cyclic constrained analogs allowed us to propose a tentative bioactive conformation of angiotensin IV and it seems that the peptide adopts an inverse gamma-turn at the C-terminal.
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Affiliation(s)
- Andreas Axén
- Department of Medicinal Chemistry, Uppsala University, Box 574, SE-75123 Uppsala, Sweden
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Laeremans H, Demaegdt H, De Backer JP, Le M, Kersemans V, Michotte Y, Vauquelin G, Vanderheyden P. Metal ion modulation of cystinyl aminopeptidase. Biochem J 2005; 390:351-7. [PMID: 15885030 PMCID: PMC1184589 DOI: 10.1042/bj20050349] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Cystinyl aminopeptidase has one Zn2+-binding motif and is a member of the M1 aminopeptidase family. Ion modulation of its catalytic activity was studied in membranes of CHO-K1 cells (Chinese-hamster ovary K1 cells) using L-leucine-p-nitroanilide as substrate. The planar bidentate chelators 1,10-phenanthroline and 2,2'-bipyridine inhibited the activity in a concentration-dependent manner with Hill slopes of 3.32+/-1.78 and 2.10+/-0.26 respectively. The acetic acid-containing chelators EDTA, EGTA and DTPA (diethylenetriamine-N,N,N',N'',N''-penta-acetic acid) weakly affected the activity, but they increased the potency of the planar chelators up to a limit, at which Hill slopes became close to unity. Moreover, competition between 1,10-phenanthroline and the substrate only took place in the presence of EDTA. These findings are compatible with a model in which the bidentate chelators inhibit enzyme activity by decreasing the free Zn2+ concentration. By removing a modulatory ion from an allosteric site at the enzyme, the acetic acid-containing chelators facilitate the direct interaction between the bidentate chelators and the catalytic Zn2+. The inhibitory effect of EDTA plus 1,10-phenanthroline could be completely reversed by Zn2+. Ca2+ and Mg2+ increased the potency of Zn2+ for this process. This is expected if they interact with the modulatory site to decrease the sensitivity of the enzyme towards 1,10-phenanthroline. Conversely, the bidendate chelators increased the high-affinity [125I]angiotensin IV binding to the membranes and this was potentiated by the acetic acid-containing chelators. These findings support the concept that high-affinity [125I]angiotensin IV binding, previously referred to as 'AT4 receptor binding', only occurs for the cystinyl aminopeptidase apoenzyme.
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Affiliation(s)
- Hilde Laeremans
- *Department of Molecular and Biochemical Pharmacology, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium
| | - Heidi Demaegdt
- *Department of Molecular and Biochemical Pharmacology, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium
| | - Jean-Paul De Backer
- *Department of Molecular and Biochemical Pharmacology, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium
| | - Minh T. Le
- *Department of Molecular and Biochemical Pharmacology, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium
| | - Veerle Kersemans
- †Laboratory of Radiopharmacy, Universiteit Gent, Harelbekestraat 72, B-9000 Ghent, Belgium
| | - Yvette Michotte
- ‡Department of Pharmaceutical Chemistry, Drug Analysis and Drug Information, Vrije Universiteit Brussel, Laarbeeklaan 103, B-1090 Brussels, Belgium
| | - Georges Vauquelin
- *Department of Molecular and Biochemical Pharmacology, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium
| | - Patrick M. L. Vanderheyden
- *Department of Molecular and Biochemical Pharmacology, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium
- To whom correspondence should be addressed (email )
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Tsujimoto M, Hattori A. The oxytocinase subfamily of M1 aminopeptidases. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2005; 1751:9-18. [PMID: 16054015 DOI: 10.1016/j.bbapap.2004.09.011] [Citation(s) in RCA: 129] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2004] [Revised: 09/03/2004] [Accepted: 09/06/2004] [Indexed: 11/26/2022]
Abstract
The placental leucine aminopeptidase (P-LAP), adipocyte-derived leucine aminopeptidase (A-LAP) and leukocyte-derived aminopeptidase (L-RAP) belong to one distinct group of the M1 family of amimopeptidases, which we term the "Oxytocinase subfamily". They share HEXXH(X)18E Zn-binding and GAMEN motifs essential for the enzymatic activities. Intracellular localization is the characteristic feature of the subfamily members. While P-LAP is translocated from intracellular vesicles to plasma membrane in a stimulus-dependent manner, both A-LAP and L-RAP are retained in the endoplasmic reticulum. They contain sequences necessary for the specific localization in the cell. It is getting evident that the subfamily members play important roles in the maintenance of homeostasis including maintenance of normal pregnancy, memory retention, blood pressure regulation and antigen presentation. In this review, current situation of this newly identified subfamily is summarized.
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Affiliation(s)
- Masafumi Tsujimoto
- Laboratory of Cellular Biochemistry, RIKEN (The Institute of Physical and Chemical Research), 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan.
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Nomura S, Ito T, Yamamoto E, Sumigama S, Iwase A, Okada M, Shibata K, Ando H, Ino K, Kikkawa F, Mizutani S. Gene regulation and physiological function of placental leucine aminopeptidase/oxytocinase during pregnancy. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2005; 1751:19-25. [PMID: 15894523 DOI: 10.1016/j.bbapap.2005.04.006] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2004] [Revised: 03/21/2005] [Accepted: 04/12/2005] [Indexed: 01/08/2023]
Abstract
Human pregnancy serum and placenta have the ability to degrade uterotonic peptide oxytocin (OT). Placental leucine aminopeptidase (P-LAP), which is also called cystine aminopeptidase, is the only membrane aminopeptidase known to functionally degrade OT as oxytocinase (OTase). P-LAP/OTase hydrolyzes several peptides other than OT including vasopressin and angiotensin III. P-LAP/OTase predicted from cDNA sequence is a type II integral membrane protein, which is converted to a soluble form existing in maternal serum by metalloproteases, possibly ADAM (a disintegrin and metalloproteinase) members. P-LAP/OTase activity increases with normal gestation, while decreases in the patients with preterm delivery and severe preeclampsia. In placenta, P-LAP/OTase is predominantly expressed in differentiated trophoblasts, syncytiotrophoblasts. Activator protein-2 (AP-2) and Ikaros transcription factors play significant roles in exerting high promoter activity of P-LAP/OTase in the trophoblastic cells. Moreover, P-LAP/OTase is transcriptionally regulated in a trophoblast-differentiation-dependent fashion via up-regulation of AP-2, putatively AP-2alpha. P-LAP/OTase may be involved in maintaining pregnancy homeostasis via metabolizing peptides such as OT and vasopressin.
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Affiliation(s)
- Seiji Nomura
- Department of Obstetrics and Gynecology, Nagoya University Graduate School of Medicine Nagoya, 466-8550, Japan.
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25
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Mustafa T, Chai SY, May CN, Mendelsohn FAO, Albiston AL. Oxytocinase/insulin-regulated aminopeptidase is distributed throughout the sheep, female reproductive tract and is regulated by oestrogen in the uterus. ACTA ACUST UNITED AC 2004; 122:85-9. [PMID: 15380925 DOI: 10.1016/j.regpep.2004.05.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2004] [Revised: 05/21/2004] [Accepted: 05/21/2004] [Indexed: 10/26/2022]
Abstract
Using [(125)I]Angiotensin IV (Ang IV) for the autoradiographic localisation of oxytocinase/insulin-regulated aminopeptidase (IRAP), we demonstrate for the first time that IRAP is distributed throughout the female reproductive tract. The highest concentration of IRAP was detected in the outer myometrial layer of the uterus with lower levels in the inner myometrial layer and in the luminal epithelium. High levels of the enzyme was also detected in the inner mucosal lining of the ampulla segment of the fallopian tubes with lower levels in the interstitial and isthmus. In the ovary, a high level of IRAP was found in the corpus albicans with lower levels throughout the ovarian cortex and the surrounding connective tissue. In the uterine body of ovariectomised (OVX) ewes, oestrogen treatment resulted in a significant decrease (P<0.05) in the level of IRAP in the outer myometrium. These findings indicate an important role for IRAP in reproductive physiology in regulating the action of peptide hormones.
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Affiliation(s)
- Tomris Mustafa
- Howard Florey Institute of Experimental Physiology and Medicine, University of Melbourne, Parkville, Victoria 3010, Australia
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26
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Ito N, Nomura S, Iwase A, Ito T, Kikkawa F, Tsujimoto M, Ishiura S, Mizutani S. ADAMs, a disintegrin and metalloproteinases, mediate shedding of oxytocinase. Biochem Biophys Res Commun 2004; 314:1008-13. [PMID: 14751233 DOI: 10.1016/j.bbrc.2003.12.183] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Placental leucine aminopeptidase (P-LAP), a type-II transmembrane protease responsible for oxytocin degradation during pregnancy, is converted to a soluble form through proteolytic cleavage. The goal of this study was to determine the nature of the P-LAP secretase activity. The hydroxamic acid-based metalloprotease inhibitors GM6001 and ONO-4817 as well as the TNF-alpha protease inhibitor-2 (TAPI-2) reduced P-LAP release, while tissue inhibitors of metalloproteinase (TIMP)-1 and TIMP-2, which are matrix metalloproteinase inhibitors, had no effect on P-LAP release in Chinese hamster ovary (CHO) cells stably overexpressing P-LAP, thus indicating possible involvement of ADAM (a disintegrin and metalloproteinase) members in P-LAP shedding. Furthermore, overexpression of ADAM9 and ADAM12 increased P-LAP release in P-LAP-CHO transfectants. Immunohistochemical analysis in human placenta demonstrated strong expression of ADAM12 in syncytiotrophoblasts, while little expression of ADAM9 was detected throughout the placenta. Our results suggest ADAM members, at least including ADAM12, are involved in P-LAP shedding in human placenta.
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Affiliation(s)
- Norio Ito
- Department of Obstetrics and Gynecology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, 466-8550, Nagoya, Japan
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27
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Nakata M, Nomura S, Ikoma Y, Sumigama S, Shido F, Ito T, Okada M, Kikkawa F, Tsujimoto M, Mizutani S. Insulin stimulates placental leucine aminopeptidase/oxytocinase/insulin-regulated membrane aminopeptidase expression in BeWo choriocarcinoma cells. ACTA ACUST UNITED AC 2004; 117:187-93. [PMID: 14749039 DOI: 10.1016/j.regpep.2003.10.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Placental leucine aminopeptidase (P-LAP), a cystine aminopeptidase that is identical to insulin-regulated membrane aminopeptidase, hydrolyzes oxytocin, which results in the loss of oxytocin activity. We previously isolated genomic clones containing the human P-LAP promoter region, which included two sites homologous to the 10-bp-insulin responsive element (IRE) that was identified on the phosphoenolpyruvate carboxinase gene. We therefore postulated that insulin regulates P-LAP expression via these IREs and investigated this notion using BeWo choriocarcinoma trophoblastic cells cultured in the presence of insulin. Insulin increased P-LAP activity in a time- and dose-dependent manner. Physiological concentrations of insulin at 10(-7) M exhibited the most potent effect on P-LAP activity. Western blotting demonstrated that 10(-7) M insulin increased P-LAP protein levels. Semi-quantitative RT-PCR and Southern blotting showed that insulin also increased P-LAP mRNA, which was abrogated by prior exposure to cycloheximide. Luciferase assay did not reveal any regulatory regions within 1.1 kb upstream of the P-LAP gene that could explain the insulin-induced P-LAP mRNA accumulation. These findings indicate that insulin induces P-LAP expression in trophoblasts, and that it acts via de novo synthesis of other proteins, which partially contradicts our initial hypothesis.
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Affiliation(s)
- Masayuki Nakata
- Department of Obstetrics and Gynecology, Graduate School of Medicine, Nagoya University, 65 Tsurumai-cho, Showa, Nagoya, 466-8550, Japan
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28
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Fujiwara H, Higuchi T, Yamada S, Hirano T, Sato Y, Nishioka Y, Yoshioka S, Tatsumi K, Ueda M, Maeda M, Fujii S. Human extravillous trophoblasts express laeverin, a novel protein that belongs to membrane-bound gluzincin metallopeptidases. Biochem Biophys Res Commun 2004; 313:962-8. [PMID: 14706636 DOI: 10.1016/j.bbrc.2003.12.024] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Human extravillous trophoblasts (EVTs) invade the maternal decidua. To identify the molecules involved in EVT invasion, we raised a murine monoclonal antibody (CHL2) that reacts with human EVTs. The molecular mass of CHL2 antigen purified from placental tissues was 160 kDa. Although the N-terminal partial amino acid sequence and one internal sequence are still unreported, the other three internal sequences matched those deduced from the coding region of the estimated sequence tag (1672 bp, AK075131). Based on this information, the full-length of the coding cDNA sequence of CHL2 antigen (2970 bp), which has not been reported elsewhere, was determined by 5' RACE. This novel protein, named laeverin, has a peptidase M1 motif containing a zinc-binding active site. It also has a transmembrane domain near the N-terminus. Its amino acid sequence is homologous with aminopeptidase N. These data indicate that human EVTs express laeverin, a novel protein belonging to gluzincin metallopeptidases.
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Affiliation(s)
- Hiroshi Fujiwara
- Department of Gynecology and Obstetrics, Kyoto University, Sakyo-ku, Kyoto 606-8507, Japan.
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29
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Caron AZ, Arguin G, Guillemette G. Angiotensin IV interacts with a juxtamembrane site on AT(4)/IRAP suggesting an allosteric mechanism of enzyme modulation. REGULATORY PEPTIDES 2003; 113:9-15. [PMID: 12686456 DOI: 10.1016/s0167-0115(02)00294-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Angiotensin IV (Ang IV), the 3-8 fragment of angiotensin II, binds to a specific receptor (AT(4)) that has recently been identified as the transmembrane aminopeptidase insulin-regulated aminopeptidase (IRAP) based on the fact that the two proteins share several pharmacological and biochemical properties. Our binding studies indicated that bovine heart expresses relatively large amounts (1.2 pmol/mg protein) of high-affinity binding sites for Ang IV (K(d)=1.8 nM). A photoaffinity-labeling approach combined with mild trypsin digestion revealed that the AT(4) receptor of bovine heart is a single transmembrane domain protein (153 kDa) with a large extracellular fragment (143 kDa). After alkaline denaturation of the AT(4) receptor, trypsin digestion produced two small membrane-associated fragments (16.9 and 6.6 kDa). These results suggest that Ang IV interacts with a juxtamembrane domain of AT(4) receptor. The location of the juxtamembrane site of contact was different from that of the active site of IRAP, suggesting that Ang IV uses an allosteric mechanism to modulate the activity of the AT(4)/IRAP.
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Affiliation(s)
- Annabelle Z Caron
- Department of Pharmacology, Faculty of Medicine, University of Sherbrooke, 3001 12th Avenue North, Sherbrooke, Quebec, Canada J1H 5N4
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30
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Arenas MI, Pérez-Márquez J. Cloning, expression, and regulation by androgens of a putative member of the oxytocinase family of proteins in the rat prostate. Prostate 2002; 53:218-24. [PMID: 12386922 DOI: 10.1002/pros.10150] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND Proteases are relevant in the physiology of the prostate, and its expression is regulated by androgens. METHODS Isolation of a novel cDNA from the rat prostate was done by reverse transcriptase-polymerase chain reaction and rapid amplification of cDNA ends. By Northern blot, we analyzed the RNA expression in different tissues and in the prostate after orchidectomy and androgen treatment. By using in situ hybridization, we studied the cellular localization of the RNA. RESULTS The cDNA codes a putative novel form of the vp-165 aminopeptidase family of proteins that we named short-vp. The short-vp probe labels one mRNA of 1.3 kb in the prostate, brain, testis, heart, and kidney. In the prostate, the levels of short-vp mRNA decrease after orchidectomy and increase with testosterone treatment. The short-vp mRNA is expressed by the prostatic epithelial cells. CONCLUSION We isolated one putative member of the oxytocinase family of proteins that is expressed in various tissues and by the epithelial cells of the prostate. The expression of short-vp mRNA in the prostate depends on androgen levels.
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Affiliation(s)
- María Isabel Arenas
- Department of Cell Biology and Genetics, Alcala de Henares University, Madrid, Spain
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31
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Cui X, Hawari F, Alsaaty S, Lawrence M, Combs CA, Geng W, Rouhani FN, Miskinis D, Levine SJ. Identification of ARTS-1 as a novel TNFR1-binding protein that promotes TNFR1 ectodomain shedding. J Clin Invest 2002. [DOI: 10.1172/jci0213847] [Citation(s) in RCA: 138] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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32
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Cui X, Hawari F, Alsaaty S, Lawrence M, Combs CA, Geng W, Rouhani FN, Miskinis D, Levine SJ. Identification of ARTS-1 as a novel TNFR1-binding protein that promotes TNFR1 ectodomain shedding. J Clin Invest 2002; 110:515-26. [PMID: 12189246 PMCID: PMC150410 DOI: 10.1172/jci13847] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Proteolytic cleavage of TNF receptor 1 (TNFR1) generates soluble receptors that regulate TNF bioactivity. We hypothesized that the mechanism of TNFR1 shedding might involve interactions with regulatory ectoproteins. Using a yeast two-hybrid approach, we identified ARTS-1 (aminopeptidase regulator of TNFR1 shedding) as a type II integral membrane protein that binds to the TNFR1 extracellular domain. In vivo binding of membrane-associated ARTS-1 to TNFR1 was confirmed by coimmunoprecipitation experiments using human pulmonary epithelial and umbilical vein endothelial cells. A direct relationship exists between membrane-associated ARTS-1 protein levels and concordant changes in TNFR1 shedding. Cells overexpressing ARTS-1 demonstrated increased TNFR1 shedding and decreased membrane-associated TNFR1, while cells expressing antisense ARTS-1 mRNA demonstrated decreased membrane-associated ARTS-1, decreased TNFR1 shedding, and increased membrane-associated TNFR1. ARTS-1 neither bound to TNFR2 nor altered its shedding, suggesting specificity for TNFR1. Although a recombinant ARTS-1 protein demonstrated selective aminopeptidase activity toward nonpolar amino acids, multiple lines of negative evidence suggest that ARTS-1 does not possess TNFR1 sheddase activity. These data indicate that ARTS-1 is a multifunctional ectoprotein capable of binding to and promoting TNFR1 shedding. We propose that formation of a TNFR1-ARTS-1 molecular complex represents a novel mechanism by which TNFR1 shedding is regulated.
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MESH Headings
- ADP Ribose Transferases/genetics
- ADP Ribose Transferases/metabolism
- Amino Acid Sequence
- Aminopeptidases/metabolism
- Antigens, CD/chemistry
- Antigens, CD/metabolism
- Base Sequence
- Carrier Proteins/genetics
- Carrier Proteins/metabolism
- Cell Line
- Cells, Cultured
- Cloning, Molecular
- Endothelium, Vascular/metabolism
- Epithelial Cells/metabolism
- GPI-Linked Proteins
- Humans
- Lung/cytology
- Lung/metabolism
- Membrane Proteins/genetics
- Membrane Proteins/metabolism
- Minor Histocompatibility Antigens
- Molecular Sequence Data
- Protein Structure, Tertiary
- Receptors, Tumor Necrosis Factor/chemistry
- Receptors, Tumor Necrosis Factor/metabolism
- Receptors, Tumor Necrosis Factor, Type I
- Tumor Cells, Cultured
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Affiliation(s)
- Xinle Cui
- Pulmonary-Critical Care Medicine Branch, National Heart, Lung, and Blood Institute, , National Institutes of Health, Bethesda, Maryland 20892-1590, USA
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33
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Nakanishi K, Yaoi K, Nagino Y, Hara H, Kitami M, Atsumi S, Miura N, Sato R. Aminopeptidase N isoforms from the midgut of Bombyx mori and Plutella xylostella -- their classification and the factors that determine their binding specificity to Bacillus thuringiensis Cry1A toxin. FEBS Lett 2002; 519:215-20. [PMID: 12023048 DOI: 10.1016/s0014-5793(02)02708-4] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Novel aminopeptidase N (APN) isoform cDNAs, BmAPN3 and PxAPN3, from the midguts of Bombyx mori and Plutella xylostella, respectively, were cloned, and a total of eight APN isoforms cloned from B. mori and P. xylostella were classified into four classes. Bacillus thuringiensis Cry1Aa and Cry1Ab toxins were found to bind to specific APN isoforms from the midguts of B. mori and P. xylostella, and binding occurred with fragments that corresponded to the BmAPN1 Cry1Aa toxin-binding region of each APN isoform. The results suggest that APN isoforms have a common toxin-binding region, and that the apparent specificity of Cry1Aa toxin binding to each intact APN isoform seen in SDS-PAGE is determined by factors such as expression level in conjunction with differences in binding affinity.
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Affiliation(s)
- Kazuko Nakanishi
- Graduate School of Bio-Applications and Systems Engineering, Tokyo University of Agriculture and Technology, Koganei, Tokyo, Japan
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34
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Abstract
Cystinyl aminopeptidase (CAP; EC 3.4.11.3) is an integral protein of the placental membrane that is also found in a soluble form in maternal serum during pregnancy. CAP was found to be shed from human placental membranes in a temperature- and time-dependent process. The released form of CAP was hydrophilic as assessed by phase separation in Triton X-114 and high-speed centrifugation. This ectodomain shedding of CAP was inhibited by the hydroxamic acid-based compounds marimastat and BB3103. The inhibition profile for the shedding of CAP was distinct to that for the release of angiotensin converting enzyme, implicating the involvement of distinct zinc metallosecretases in the shedding of these two proteins. These results have implications for our understanding of the mechanism underlying the reduction in serum levels of CAP observed in certain pregnancy-related disorders, such as pre-eclampsia.
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Affiliation(s)
- L D Ofner
- Proteolysis Research Group, School of Biochemistry and Molecular Biology, University of Leeds, Leeds, LS2 9JT, UK
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35
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Emmerling M, Chandler D, Sandeman M. Molecular cloning of three cDNAs encoding aminopeptidases from the midgut of Helicoverpa punctigera, the Australian native budworm. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2001; 31:899-907. [PMID: 11439249 DOI: 10.1016/s0965-1748(01)00036-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Three cDNAs encoding aminopeptidases HpAPN1, HpAPN2 and HpAPN3, were isolated from a 5th instar larval midgut cDNA library from Helicoverpa punctigera, the Australian native budworm. The sequences recovered contain open reading frames encoding proteins of 1011, 952, and 1013 amino acids, respectively. All three proteins share the consensus zinc binding/gluzincin motif HEXXHX(18)E and the sequence GAMEN common to gluzincin aminopeptidases. Furthermore, signal peptide sequences and C-terminal hydrophobic regions preceded by three small amino acids qualifying for cleavage and GPI anchor attachment are present in all three protein sequences. Northern blotting results indicate differences in the levels of expression and developmental regulation of all three aminopeptidases. HpAPN1, HpAPN2, and HpAPN3 are more closely related to APNs from other lepidopterans than they are to each other. This report of three different aminopeptidases N in Helicoverpa punctigera adds support to a recent suggestion that at least one gene duplication has taken place in ancestral lepidopterans. The full sequences of the aminopeptidases are available at GENBANK with the following accession numbers: HpAPN1: AF217248, HpAPN2: AF217249, HpAPN3: AF217250.
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Affiliation(s)
- M Emmerling
- Plant Biotechnology Centre, Agriculture Victoria, La Trobe University, 3086, Victoria, Australia
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36
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Matsumoto H, Nagasaka T, Hattori A, Rogi T, Tsuruoka N, Mizutani S, Tsujimoto M. Expression of placental leucine aminopeptidase/oxytocinase in neuronal cells and its action on neuronal peptides. EUROPEAN JOURNAL OF BIOCHEMISTRY 2001; 268:3259-66. [PMID: 11389728 DOI: 10.1046/j.1432-1327.2001.02221.x] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The placental leucine aminopeptidase (P-LAP)/oxytocinase whose serum level increases with gestation is thought to contribute to the maintenance of normal pregnancy. P-LAP mRNAs are expressed in various tissues other than the placenta. In this study, we identified P-LAP protein in the brain. In contrast with the placenta where a significant portion of P-LAP is released, the enzyme was localized in the membrane fraction in brain and PC12 cells and no soluble form of the enzyme was detected. When PC12 cells were differentiated into neuronal cells by nerve growth factor (NGF), a significant increase in the expression level of P-LAP in the cell was observed. As in the case of insulin treatment of 3T3-L1 adipocytes, treatment of PC12 cells with forskolin caused the translocation of the enzyme from intracellular vesicle to the cell surface plasma membrane. In addition, P-LAP was shown to degrade several bioactive neuropeptides such as Met-enkephalin and dynorphin A (1-8). These results suggest that P-LAP plays an important role in the regulation of neuronal cell function in the brain.
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Affiliation(s)
- H Matsumoto
- Laboratory of Cellular Biochemistry, RIKEN (The Institute of Physical and Chemical Research) Wako, Saitama, Japan
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37
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Laustsen PG, Vang S, Kristensen T. Mutational analysis of the active site of human insulin-regulated aminopeptidase. EUROPEAN JOURNAL OF BIOCHEMISTRY 2001; 268:98-104. [PMID: 11121108 DOI: 10.1046/j.1432-1327.2001.01848.x] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Insulin-regulated aminopeptidase (IRAP) is a type II integral membrane protein belonging to the gluzincin family of metallopeptidases identified by the characteristic Zn(2+)-coordination sequence element, HEXXH-(18-64X)-E. A second conserved sequence element, the GXMEN motif, positioned 22-32 amino acids N-terminal to the Zn(2+)-coordination sequence element distinguishes the gluzincin aminopeptidases from other gluzincins. To investigate the importance of the G428AMEN and H464ELAH-(18X)-E487 motifs for the activity of IRAP, mutational analysis was carried out. cDNA encoding the full-length transmembrane form of human IRAP was expressed in HEK293 cells and recombinant wild-type IRAP was shown to have biochemical and enzymatic properties similar to those reported for native IRAP and the soluble serum form of IRAP. Mutational analysis using single amino-acid substitutions in the GAMEN motif (G428A, A429G, M430K, M430E, M430I, E431D and E431A) and in the Zn(2+)-binding motif (H464Y, E465D, E465Q, H468Y, E487D and E487Q) resulted in decreased or abolished aminopeptidase activity towards the leucine-para-nitroanilide substrate. The results show that conservation of residues within the GAMEN and Zn(2+)-binding motifs is important for IRAP enzyme activity.
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Affiliation(s)
- P G Laustsen
- Department of Molecular and Structural Biology, University of Aarhus, Denmark
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38
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Rasmussen TE, Pedraza-Díaz S, Hardré R, Laustsen PG, Carríon AG, Kristensen T. Structure of the human oxytocinase/insulin-regulated aminopeptidase gene and localization to chromosome 5q21. EUROPEAN JOURNAL OF BIOCHEMISTRY 2000; 267:2297-306. [PMID: 10759854 DOI: 10.1046/j.1432-1327.2000.01234.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The human oxytocinase/insulin-regulated aminopeptidase (OTase/IRAP) is a 1024 amino acid type II integral membrane protein that is expressed mainly in fat, muscle and placenta tissues. It has been thought to be involved mainly in the control of onset of labour but recently rat OTase/IRAP was shown to participate in the regulation of glucose transporter isoform 4 vesicle trafficking in adipocytes as well. To approach an understanding of OTase/IRAP gene regulation the organization of the human gene was determined. Accordingly, three overlapping genomic clones were isolated and characterized. The human OTase/IRAP gene (OTASE) was found to span approximately 75 kb containing 18 exons and 17 introns. The gluzincin aminopeptidase motif: GAMEN-(31 amino acids)-HELAH-(18 amino acids)-E associated with Zn2+-binding, substrate binding and catalysis is encoded by exons 6 and 7. A major and a minor transcriptional initiation site in OTASE were identified by primer extension 514 bp and 551 bp, respectively, upstream of the translation start codon. Chloroamphenicol acetyltransferase-reporter assays revealed a functional CpG-rich promoter/enhancer region located between nucleotide -621 and the major transcriptional initiation site. Human OTASE was assigned to chromosome 5 by hybridization to genomic DNA from characterized somatic cell hybrids. Finally, the OTASE and the human aminopeptidase A gene were subchromosomally localized to 5q21 and 4q25, respectively, by in situ hybridization.
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Affiliation(s)
- T E Rasmussen
- Department of Molecular and Structural Biology, University of Aarhus, Denmark
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39
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Yamahara N, Nomura S, Suzuki T, Itakura A, Ito M, Okamoto T, Tsujimoto M, Nakazato H, Mizutani S. Placental leucine aminopeptidase/oxytocinase in maternal serum and placenta during normal pregnancy. Life Sci 2000; 66:1401-10. [PMID: 11210715 DOI: 10.1016/s0024-3205(00)00451-3] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Placental leucine aminopeptidase (P-LAP), which is identical with cystine aminopeptidase as oxytocinase, was found to be homologous with rat insulin-regulated membrane aminopeptidase (IRAP) by sequence comparison. In the current study, we determined the P-LAP levels in maternal serum and placenta during healthy pregnancy. P-LAP activities in maternal serum increased with gestation and rose to the peak of 80 IU/ml at 38 weeks of gestation. Northern blot analysis revealed the increase of P-LAP mRNA levels in placenta in the third trimester compared to the first trimester. P-LAP protein and related activities could be detected in the conditioned medium of placental tissue, while they could not be detected in that of human umbilical vein endothelial cells. Immunohistochemically P-LAP was positively stained in the apical membrane of syncytiotrophoblast cells throughout the gestation. These results established the normal range of serum and tissue P-LAP levels during pregnancy and the possible source of serum P-LAP, which will be helpful to elucidate the physiological and clinical roles of P-LAP/oxytocinase/IRAP.
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Affiliation(s)
- N Yamahara
- Department of Obstetrics and Gynecology, Nagoya University School of Medicine, Nagoya 466-8550, Japan
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40
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Matsumoto H, Rogi T, Yamashiro K, Kodama S, Tsuruoka N, Hattori A, Takio K, Mizutani S, Tsujimoto M. Characterization of a recombinant soluble form of human placental leucine aminopeptidase/oxytocinase expressed in Chinese hamster ovary cells. EUROPEAN JOURNAL OF BIOCHEMISTRY 2000; 267:46-52. [PMID: 10601849 DOI: 10.1046/j.1432-1327.2000.00949.x] [Citation(s) in RCA: 91] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Serum levels of human placental leucine aminopeptidase/oxytocinase (P-LAP) increase with gestation. cDNA cloning of P-LAP revealed that the enzyme is a type II membrane-bound protein containing the consensus HEXXH(X)18E motif found in the M1 family of zinc-metallopeptidase proteins. In this study, a recombinant soluble form of P-LAP found in maternal serum was expressed in Chinese hamster ovary cells, purified to homogeneity and then characterized. Although N-terminal sequencing revealed a four-amino-acid deletion, the purified enzyme was active and was shown to be a zinc-containing homodimeric protein with molecular mass of 280 kDa in solution. Using artificial substrates, it was shown that the enzyme has broad specificity and is inhibited by several compounds known as aminopeptidase inhibitors. Subsequently, sequential N-terminal amino-acid liberation of several peptide hormones by the enzyme was monitored and structures of the products were determined. Among the hormones having a cysteine residue at their N-terminal end and intramolecular disulfide bonds, it was found that vasopressin and oxytocin, but not calcitonin and endothelins, were cleaved by the enzyme. Because the molecular properties of oxytocinase so far reported often conflict, our results provide an initial biochemical and enzymatic characterization of moleculary defined P-LAP/oxytocinase.
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Affiliation(s)
- H Matsumoto
- The Institute of Phyical and Chemical Research (RIKEN), Wako-shi, Saitama, Japan
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Horio J, Nomura S, Okada M, Katsumata Y, Nakanishi Y, Kumano Y, Takami S, Kinoshita M, Tsujimoto M, Nakazato H, Mizutani S. Structural organization of the 5'-end and chromosomal assignment of human placental leucine aminopeptidase/insulin-regulated membrane aminopeptidase gene. Biochem Biophys Res Commun 1999; 262:269-74. [PMID: 10448104 DOI: 10.1006/bbrc.1999.1184] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Placental leucine aminopeptidase (P-LAP) which is identical with cystine aminopeptidase as oxytocinase was found to be a homologue of rat insulin-regulated membrane aminopeptidase (IRAP) by cDNA cloning. In this study, we confirmed 5'-end cDNA sequence of P-LAP and isolated genomic clones containing the upstream region of human P-LAP gene. The transcription initiation sites determined by primer extension located 478 and 480 bp upstream of the initiation methionine codon, 38 bp downstream of TATA box-like motif. The 5'-flanking region of human P-LAP gene contained DNA-binding motifs for several ubiquitous transcription factors such as SP1 and AP2. Chromosomal localization by fluorescence in situ hybridization showed that the gene was assigned to 5q14.2-q15 of the human chromosome. This study establishes the genetic basis for P-LAP gene research, thereby leading to better understanding of the molecular mechanism underlying the P-LAP gene.
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Affiliation(s)
- J Horio
- Department of Obstetrics and Gynecology, Nagoya University School of Medicine, Nagoya, 466-8550, Japan
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Florent I, Derhy Z, Allary M, Monsigny M, Mayer R, Schrével J. A Plasmodium falciparum aminopeptidase gene belonging to the M1 family of zinc-metallopeptidases is expressed in erythrocytic stages. Mol Biochem Parasitol 1998; 97:149-60. [PMID: 9879894 DOI: 10.1016/s0166-6851(98)00143-1] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
A new single copy gene has been isolated from Plasmodium falciparum, by immunoscreening a genomic DNA expression library. The gene appears devoid of introns, displays the classical A + T richness and codon usage of P. falciparum genes, and is transcribed into a 4 kb mRNA in erythrocytic stages. The deduced amino acid sequence corresponds to a 1056 residue protein (122 kDa) containing the canonical HExxHx18E signature of zinc-metallopeptidase active sites of the M1 family at position 467-490, a downstream conserved tyrosine residue involved in catalysis in position 551, and the GAMEN conserved motif characteristic of aminopeptidases in the M1 family, at position 431-435. The greatest similarities were found with aminopeptidases N of Escherichia coli and Haemophilius influenza (more than 80% identical residues in the canonical signature of the active site) but significant similarities centred on the active site region exist with all other members of the M1 family such as other prokaryotic aminopeptidases, eukaryotic aminopeptidases A and N and leukotriene A4 hydrolases (40-50% identical residues in the canonical signature of the active site). A polyclonal serum raised to a synthetic peptide deduced from the gene labelled schizont proteins of 96 and 68 kDa purified to homogeneity and both displaying aminopeptidase activity, as well as cytoplasmic structures in schizont stages.
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Affiliation(s)
- I Florent
- Laboratoire de Biologie Parasitaire, EP 1790 Biologie et Evolution des Parasites CNRS, Muséum National d'Histoire Naturelle, Paris, France.
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Hua G, Tsukamoto K, Taguchi R, Tomita M, Miyajima S, Ikezawa H. Characterization of aminopeptidase N from the brush border membrane of the larvae midgut of silkworm, Bombyx mori as a zinc enzyme. BIOCHIMICA ET BIOPHYSICA ACTA 1998; 1383:301-10. [PMID: 9602161 DOI: 10.1016/s0167-4838(97)00222-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Three GPI-anchored proteins, aminopeptidase N, alkaline phosphatase and alkaline phosphodiesterase I were released from the midgut brush border membrane of Bombyx mori by phosphatidylinositol-specific phopholipase C and the aminopeptidase N was purified to a homogeneous state. N-terminus and 6 internal sequences, one of which possessed part of zinc-binding motif, showed homology with those from other species. The zinc content in purified aminopeptidase N was estimated as approximately 0.72 mol/mol of the protein and 1,10-phenanthroline completely inhibited the enzyme activity, suggesting zinc requirement for the activity. The aminopeptidase N activity was inhibited not only by probestin and actinonin, but also strongly depressed by amastatin, while leuhistin and bestatin were less inhibitory. These suggest that the active site of aminopeptidase N might be structurally different from those of mammals. Calcium and magnesium ions stimulated the aminopeptidase N activity, but copper ion was rather inhibitory. Zinc ion showed bi-modal effect on the activity, i.e., stimulatory at low concentration, but inhibitory at higher than 100 microM. This inhibition was completely restored by EDTA. These results suggest that the aminopeptidase N possesses two zinc ion-binding sites with high and low affinity as essential and inhibitory one, as well as some regulatory metal-binding sites.
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Affiliation(s)
- G Hua
- Department of Microbial Chemistry, Faculty of Pharmaceutical Sciences, Nagoya City University, Aichi, Japan
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Watanabe Y, Ito K, Iwaki-Egawa S, Yamaguchi R, Fujimoto Y. Aminopeptidase N in sera of healthy subjects is a different N-terminal processed derivative from the one obtained from maternal serum. Mol Genet Metab 1998; 63:289-94. [PMID: 9635297 DOI: 10.1006/mgme.1998.2676] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
A major aminopeptidase present in normal human serum was purified to homogeneity as a 150-kDa molecular species. Western blotting confirmed the binding of an anti-aminopeptidase N antibody to the protein. The N-terminal amino acid sequence of the enzyme was determined. The first 13 amino acids of the enzyme completely matched amino acids 59-71 of the sequence predicted from the human intestinal aminopeptidase N cDNA nucleotide sequence. As reported previously, aminopeptidase N from maternal serum had 68 fewer amino acid residues at the N-terminus than the enzyme obtained from detergent-solubilized membranes. The results indicate that aminopeptidase N in normal serum is a different N-terminal processed derivative from that obtained from maternal serum.
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Affiliation(s)
- Y Watanabe
- Department of Clinical Biochemistry, Hokkaido College of Pharmacy, Japan
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