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Identification of Kukoamine A, Zeaxanthin, and Clexane as New Furin Inhibitors. Int J Mol Sci 2022; 23:ijms23052796. [PMID: 35269938 PMCID: PMC8911046 DOI: 10.3390/ijms23052796] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 02/23/2022] [Accepted: 02/25/2022] [Indexed: 02/01/2023] Open
Abstract
The endogenous protease furin is a key protein in many different diseases, such as cancer and infections. For this reason, a wide range of studies has focused on targeting furin from a therapeutic point of view. Our main objective consisted of identifying new compounds that could enlarge the furin inhibitor arsenal; secondarily, we assayed their adjuvant effect in combination with a known furin inhibitor, CMK, which avoids the SARS-CoV-2 S protein cleavage by means of that inhibition. Virtual screening was carried out to identify potential furin inhibitors. The inhibition of physiological and purified recombinant furin by screening selected compounds, Clexane, and these drugs in combination with CMK was assayed in fluorogenic tests by using a specific furin substrate. The effects of the selected inhibitors from virtual screening on cell viability (293T HEK cell line) were assayed by means of flow cytometry. Through virtual screening, Zeaxanthin and Kukoamine A were selected as the main potential furin inhibitors. In fluorogenic assays, these two compounds and Clexane inhibited both physiological and recombinant furin in a dose-dependent way. In addition, these compounds increased physiological furin inhibition by CMK, showing an adjuvant effect. In conclusion, we identified Kukoamine A, Zeaxanthin, and Clexane as new furin inhibitors. In addition, these drugs were able to increase furin inhibition by CMK, so they could also increase its efficiency when avoiding S protein proteolysis, which is essential for SARS-CoV-2 cell infection.
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He Z, Khatib AM, Creemers JWM. The proprotein convertase furin in cancer: more than an oncogene. Oncogene 2022; 41:1252-1262. [PMID: 34997216 DOI: 10.1038/s41388-021-02175-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 12/13/2021] [Accepted: 12/30/2021] [Indexed: 02/01/2023]
Abstract
Furin is the first discovered proprotein convertase member and is present in almost all mammalian cells. Therefore, by regulating the maturation of a wide range of proproteins, Furin expression and/or activity is involved in various physiological and pathophysiological processes ranging from embryonic development to carcinogenesis. Since many of these protein precursors are involved in initiating and maintaining the hallmarks of cancer, Furin has been proposed as a potential target for treating several human cancers. In contrast, other studies have revealed that some types of cancer do not benefit from Furin inhibition. Therefore, understanding the heterogeneous functions of Furin in cancer will provide important insights into the design of effective strategies targeting Furin in cancer treatment. Here, we present recent advances in understanding how Furin expression and activity are regulated in cancer cells and their influences on the activity of Furin substrates in carcinogenesis. Furthermore, we discuss how Furin represses tumorigenic properties of several cancer cells and why Furin inhibition leads to aggressive phenotypes in other tumors. Finally, we summarize the clinical applications of Furin inhibition in treating human cancers.
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Affiliation(s)
- Zongsheng He
- Department of Gastroenterology, Daping Hospital, Army Medical University, Chongqing, China
- Laboratory of Biochemical Neuroendocrinology, Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Abdel-Majid Khatib
- INSERM, LAMC, UMR 1029, Allée Geoffroy St Hilaire, Pessac, France.
- Institut Bergoinié, Bordeaux, France.
| | - John W M Creemers
- Laboratory of Biochemical Neuroendocrinology, Department of Human Genetics, KU Leuven, Leuven, Belgium.
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Seidah NG. The PCSK9 discovery, an inactive protease with varied functions in hypercholesterolemia, viral infections, and cancer. J Lipid Res 2021; 62:100130. [PMID: 34606887 PMCID: PMC8551645 DOI: 10.1016/j.jlr.2021.100130] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 08/19/2021] [Accepted: 08/21/2021] [Indexed: 01/06/2023] Open
Abstract
In 2003, the sequences of mammalian proprotein convertase subtilisin/kexin type 9 (PCSK9) were reported. Radiolabeling pulse-chase analyses demonstrated that PCSK9 was synthesized as a precursor (proPCSK9) that undergoes autocatalytic cleavage in the endoplasmic reticulum into PCSK9, which is then secreted as an inactive enzyme in complex with its inhibitory prodomain. Its high mRNA expression in liver hepatocytes and its gene localization on chromosome 1p32, a third locus associated with familial hypercholesterolemia, other than LDLR or APOB, led us to identify three patient families expressing the PCSK9 variants S127R or F216L. Although Pcsk9 and Ldlr were downregulated in mice that were fed a cholesterol-rich diet, PCSK9 overexpression led to the degradation of the LDLR. This led to the demonstration that gain-of-function and loss-of-function variations in PCSK9 modulate its bioactivity, whereby PCSK9 binds the LDLR in a nonenzymatic fashion to induce its degradation in endosomes/lysosomes. PCSK9 was also shown to play major roles in targeting other receptors for degradation, thereby regulating various processes, including hypercholesterolemia and associated atherosclerosis, vascular inflammation, viral infections, and immune checkpoint regulation in cancer. Injectable PCSK9 monoclonal antibody or siRNA is currently used in clinics worldwide to treat hypercholesterolemia and could be combined with current therapies in cancer/metastasis. In this review, we present the critical information that led to the discovery of PCSK9 and its implication in LDL-C metabolism. We further analyze the underlying functional mechanism(s) in the regulation of LDL-C, as well as the evolving novel roles of PCSK9 in both health and disease states.
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Affiliation(s)
- Nabil G Seidah
- Laboratory of Biochemical Neuroendocrinology, Montreal Clinical Research Institute (IRCM, affiliated to the University of Montreal), 110 Pine Ave West, Montreal, QC, H2W 1R7, Canada.
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Screening for inhibitory effects of crude drugs on furin-like enzymatic activities. J Nat Med 2021; 75:1080-1085. [PMID: 33928494 PMCID: PMC8084592 DOI: 10.1007/s11418-021-01519-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 04/16/2021] [Indexed: 11/18/2022]
Abstract
The spike (S) protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) contains a cleavage motif R-X-X-R for furin-like enzymes at the boundary of the S1/S2 subunits. The cleavage of the site by cellular proteases is essential for S protein activation and virus entry. We screened the inhibitory effects of crude drugs on in vitro furin-like enzymatic activities using a fluorogenic substrate with whole-cell lysates. Of the 124 crude drugs listed in the Japanese Pharmacopeia, aqueous ethanolic extract of Cnidii Monnieris Fructus, which is the dried fruit of Cnidium monnieri Cussion, significantly inhibited the furin-like enzymatic activities. We further fractionated the plant extract and isolated the two active compounds with the inhibitory activity, namely, imperatorin and osthole, whose IC50 values were 1.45 mM and 9.45 µM, respectively. Our results indicated that Cnidii Monnieris Fructus might exert inhibitory effects on furin-like enzymatic activities, and that imperatorin and osthole of the crude drug could be potential inhibitors of the motif cleavage.
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Przybyłek M. Application 2D Descriptors and Artificial Neural Networks for Beta-Glucosidase Inhibitors Screening. Molecules 2020; 25:E5942. [PMID: 33333961 PMCID: PMC7765417 DOI: 10.3390/molecules25245942] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 12/12/2020] [Accepted: 12/14/2020] [Indexed: 12/14/2022] Open
Abstract
Beta-glucosidase inhibitors play important medical and biological roles. In this study, simple two-variable artificial neural network (ANN) classification models were developed for beta-glucosidase inhibitors screening. All bioassay data were obtained from the ChEMBL database. The classifiers were generated using 2D molecular descriptors and the data miner tool available in the STATISTICA package (STATISTICA Automated Neural Networks, SANN). In order to evaluate the models' accuracy and select the best classifiers among automatically generated SANNs, the Matthews correlation coefficient (MCC) was used. The application of the combination of maxHBint3 and SpMax8_Bhs descriptors leads to the highest predicting abilities of SANNs, as evidenced by the averaged test set prediction results (MCC = 0.748) calculated for ten different dataset splits. Additionally, the models were analyzed employing receiver operating characteristics (ROC) and cumulative gain charts. The thirteen final classifiers obtained as a result of the model development procedure were applied for a natural compounds collection available in the BIOFACQUIM database. As a result of this beta-glucosidase inhibitors screening, eight compounds were univocally classified as active by all SANNs.
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Affiliation(s)
- Maciej Przybyłek
- Department of Physical Chemistry, Pharmacy Faculty, Collegium Medicum of Bydgoszcz, Nicolaus Copernicus University in Toruń, Kurpińskiego 5, 85-950 Bydgoszcz, Poland
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Reelin-Nrp1 Interaction Regulates Neocortical Dendrite Development in a Context-Specific Manner. J Neurosci 2020; 40:8248-8261. [PMID: 33009002 DOI: 10.1523/jneurosci.1907-20.2020] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 09/14/2020] [Accepted: 09/23/2020] [Indexed: 11/21/2022] Open
Abstract
Reelin plays versatile roles in neocortical development. The C-terminal region (CTR) of Reelin is required for the correct formation of the superficial structure of the neocortex; however, the mechanisms by which this position-specific effect occurs remain largely unknown. In this study, we demonstrate that Reelin with an intact CTR binds to neuropilin-1 (Nrp1), a transmembrane protein. Both male and female mice were used. Nrp1 is localized with very-low-density lipoprotein receptor (VLDLR), a canonical Reelin receptor, in the superficial layers of the developing neocortex. It forms a complex with VLDLR, and this interaction is modulated by the alternative splicing of VLDLR. Reelin with an intact CTR binds more strongly to the VLDLR/Nrp1 complex than to VLDLR alone. Knockdown of Nrp1 in neurons leads to the accumulation of Dab1 protein. Since the degradation of Dab1 is induced by Reelin signaling, it is suggested that Nrp1 augments Reelin signaling. The interaction between Reelin and Nrp1 is required for normal dendritic development in superficial-layer neurons. All of these characteristics of Reelin are abrogated by proteolytic processing of the six C-terminal amino acid residues of Reelin (0.17% of the whole protein). Therefore, Nrp1 is a coreceptor molecule for Reelin and, together with the proteolytic processing of Reelin, can account for context-specific Reelin function in brain development.SIGNIFICANCE STATEMENT Reelin often exhibits a context-dependent function during brain development; however, its underlying mechanism is not well understood. We found that neuropilin-1 (Nrp1) specifically binds to the CTR of Reelin and acts as a coreceptor for very-low-density lipoprotein receptor (VLDLR). The Nrp1/VLDLR complex is localized in the superficial layers of the neocortex, and its interaction with Reelin is essential for proper dendritic development in superficial-layer neurons. This study provides the first mechanistic evidence of the context-specific function of Reelin (>3400 residues) regulated by the C-terminal residues and Nrp1, a component of the canonical Reelin receptor complex.
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Nemunaitis J, Stanbery L, Senzer N. Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection: let the virus be its own demise. Future Virol 2020. [PMCID: PMC7249572 DOI: 10.2217/fvl-2020-0068] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
There has been a collaborative global effort to construct novel therapeutic and prophylactic approaches to SARS-CoV-2 management. Although vaccine development is crucial, acute management of newly infected patients, especially those with severe acute respiratory distress syndrome, is a priority. Herein we describe the rationale and potential of repurposing a dual plasmid, Vigil (pbi-shRNAfurin-GM-CSF), now in Phase III cancer trials, for the treatment of and, in certain circumstances, enhancement of the immune response to SARS-CoV-2.
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Boon L, Ugarte-Berzal E, Vandooren J, Opdenakker G. Protease propeptide structures, mechanisms of activation, and functions. Crit Rev Biochem Mol Biol 2020; 55:111-165. [PMID: 32290726 DOI: 10.1080/10409238.2020.1742090] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Proteases are a diverse group of hydrolytic enzymes, ranging from single-domain catalytic molecules to sophisticated multi-functional macromolecules. Human proteases are divided into five mechanistic classes: aspartate, cysteine, metallo, serine and threonine proteases, based on the catalytic mechanism of hydrolysis. As a protective mechanism against uncontrolled proteolysis, proteases are often produced and secreted as inactive precursors, called zymogens, containing inhibitory N-terminal propeptides. Protease propeptide structures vary considerably in length, ranging from dipeptides and propeptides of about 10 amino acids to complex multifunctional prodomains with hundreds of residues. Interestingly, sequence analysis of the different protease domains has demonstrated that propeptide sequences present higher heterogeneity compared with their catalytic domains. Therefore, we suggest that protease inhibition targeting propeptides might be more specific and have less off-target effects than classical inhibitors. The roles of propeptides, besides keeping protease latency, include correct folding of proteases, compartmentalization, liganding, and functional modulation. Changes in the propeptide sequence, thus, have a tremendous impact on the cognate enzymes. Small modifications of the propeptide sequences modulate the activity of the enzymes, which may be useful as a therapeutic strategy. This review provides an overview of known human proteases, with a focus on the role of their propeptides. We review propeptide functions, activation mechanisms, and possible therapeutic applications.
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Affiliation(s)
- Lise Boon
- Rega Institute for Medical Research, Department of Microbiology, Immunology and Transplantation, Laboratory of Immunobiology, KU Leuven, Leuven, Belgium
| | - Estefania Ugarte-Berzal
- Rega Institute for Medical Research, Department of Microbiology, Immunology and Transplantation, Laboratory of Immunobiology, KU Leuven, Leuven, Belgium
| | - Jennifer Vandooren
- Rega Institute for Medical Research, Department of Microbiology, Immunology and Transplantation, Laboratory of Immunobiology, KU Leuven, Leuven, Belgium
| | - Ghislain Opdenakker
- Rega Institute for Medical Research, Department of Microbiology, Immunology and Transplantation, Laboratory of Immunobiology, KU Leuven, Leuven, Belgium
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Durand L, Duval S, Evagelidis A, Guillemot J, Dianati V, Sikorska E, Schu P, Day R, Seidah NG. The motif E XE XXXL in the cytosolic tail of the secretory human proprotein convertase PC7 regulates its trafficking and cleavage activity. J Biol Chem 2020; 295:2068-2083. [PMID: 31915245 DOI: 10.1074/jbc.ra119.011775] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 12/17/2019] [Indexed: 02/05/2023] Open
Abstract
Many secretory proteins are activated by cleavage at specific sites. The proprotein convertases (PCs) form a family of nine secretory subtilisin-like serine proteases, seven of which cleave at specific basic residues within the trans-Golgi network, granules, or at the cell surface/endosomes. The seventh member, PC7, is a type-I transmembrane (TM) protein with a 97-residue-long cytosolic tail (CT). PC7 sheds human transferrin receptor 1 (hTfR1) into soluble shTfR1 in endosomes. To better understand the physiological roles of PC7, here we focused on the relationship between the CT-regulated trafficking of PC7 and its ability to shed hTfR1. Deletion of the TMCT resulted in soluble PC7 and loss of its hTfR1 shedding activity. Extensive CT deletions and mutagenesis analyses helped us zoom in on three residues in the CT, namely Glu-719, Glu-721, and Leu-725, that are part of a novel motif, EXEXXXL725, critical for PC7 activity on hTfR1. NMR studies of two 14-mer peptides mimicking this region of the CT and its Ala variants revealed that the three exposed residues are on the same side of the molecule. This led to the identification of adaptor protein 2 (AP-2) as a protein that recognizes the EXEXXXL725 motif, thus representing a potentially new regulator of PC7 trafficking and cleavage activity. Immunocytochemistry of the subcellular localization of PC7 and its Ala variants of Leu-725 and Glu-719 and Glu-721 revealed that Leu-725 enhances PC7 localization to early endosomes and that, together with Glu-719 and Glu-721, it increases the endosomal activity of PC7 on hTfR1.
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Affiliation(s)
- Loreleï Durand
- Laboratory of Biochemical Neuroendocrinology, Clinical Research of Montreal, affiliated with Université de Montréal, Montreal, Quebec H2W 1R7, Canada
| | - Stéphanie Duval
- Laboratory of Biochemical Neuroendocrinology, Clinical Research of Montreal, affiliated with Université de Montréal, Montreal, Quebec H2W 1R7, Canada
| | - Alexandra Evagelidis
- Laboratory of Biochemical Neuroendocrinology, Clinical Research of Montreal, affiliated with Université de Montréal, Montreal, Quebec H2W 1R7, Canada
| | - Johann Guillemot
- CIRI, Centre International de Recherche en Infectiologie, Team Pathogenesis of Legionella, INSERM U1111, Université Claude Bernard Lyon 1, CNRS UMR5308, École Normale Supérieure de Lyon, Université Lyon, Villeurbanne, 69100 France
| | - Vahid Dianati
- Institut de Pharmacologie de Sherbrooke, Department of Surgery/Urology Division, and Faculté de Médecine et des Sciences de la Santé, Sherbrooke, Quebec J 1H 5N4, Canada
| | - Emilia Sikorska
- Faculty of Chemistry, University of Gdańsk, Gdańsk, 80-233 Poland
| | - Peter Schu
- Department of Cellular Biochemistry, University Medical Center, Göttingen, Humboldtallee 23, 37073 Goettingen, Germany
| | - Robert Day
- Institut de Pharmacologie de Sherbrooke, Department of Surgery/Urology Division, and Faculté de Médecine et des Sciences de la Santé, Sherbrooke, Quebec J 1H 5N4, Canada
| | - Nabil G Seidah
- Laboratory of Biochemical Neuroendocrinology, Clinical Research of Montreal, affiliated with Université de Montréal, Montreal, Quebec H2W 1R7, Canada.
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Braun E, Sauter D. Furin-mediated protein processing in infectious diseases and cancer. Clin Transl Immunology 2019; 8:e1073. [PMID: 31406574 PMCID: PMC6682551 DOI: 10.1002/cti2.1073] [Citation(s) in RCA: 195] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 07/10/2019] [Accepted: 07/13/2019] [Indexed: 12/17/2022] Open
Abstract
Proteolytic cleavage regulates numerous processes in health and disease. One key player is the ubiquitously expressed serine protease furin, which cleaves a plethora of proteins at polybasic recognition motifs. Mammalian substrates of furin include cytokines, hormones, growth factors and receptors. Thus, it is not surprising that aberrant furin activity is associated with a variety of disorders including cancer. Furthermore, the enzymatic activity of furin is exploited by numerous viral and bacterial pathogens, thereby enhancing their virulence and spread. In this review, we describe the physiological and pathophysiological substrates of furin and discuss how dysregulation of a simple proteolytic cleavage event may promote infectious diseases and cancer. One major focus is the role of furin in viral glycoprotein maturation and pathogenicity. We also outline cellular mechanisms regulating the expression and activation of furin and summarise current approaches that target this protease for therapeutic intervention.
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Affiliation(s)
- Elisabeth Braun
- Institute of Molecular VirologyUlm University Medical CenterUlmGermany
| | - Daniel Sauter
- Institute of Molecular VirologyUlm University Medical CenterUlmGermany
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Baumann J, Huang SF, Gassmann M, Tsao CC, Ogunshola OO. Furin inhibition prevents hypoxic and TGFβ-mediated blood-brain barrier disruption. Exp Cell Res 2019; 383:111503. [PMID: 31336100 DOI: 10.1016/j.yexcr.2019.111503] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Revised: 06/25/2019] [Accepted: 07/15/2019] [Indexed: 12/12/2022]
Abstract
Hypoxic blood-brain barrier (BBB) dysfunction is a common feature of CNS diseases however mechanisms underlying barrier disturbance are still largely unknown. This study investigated the role of transforming growth factor β (TGFβ), a cytokine known to induce expression of the proprotein convertase Furin, in hypoxia-mediated barrier compromise. We show that exposure of brain endothelial cells (ECs) to hypoxia (1% O2) rapidly stimulates their migration. Additional exogenous TGFβ (0.4 nM) exposure potentiated this effect and increased Furin expression in a TGFβ type I receptor activin-like kinase 5 (ALK5) - dependent manner (prevented by 10 μM SB431542). Furin inhibition prevented hypoxia-induced EC migration and blocked TGFβ-induced potentiation suggesting existence of a feedback loop. TGFβ and Furin were also critical for hypoxia-induced BBB dysfunction. TGFβ treatment aggravated hypoxia-induced BBB permeability but ALK5 or Furin blockade reversed injury-induced permeability changes. Thus during insult Furin compromises endothelial integrity by mediating the effects of TGFβ. Targeting the Furin or ALK5 pathway may offer novel therapeutic strategies for improving BBB stability and CNS function during disease.
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Affiliation(s)
- Julia Baumann
- Institute of Veterinary Physiology, Vetsuisse Faculty and Zurich Center Integrative Physiology (ZIHP), University of Zurich, Zurich, Switzerland
| | - Sheng-Fu Huang
- Institute of Veterinary Physiology, Vetsuisse Faculty and Zurich Center Integrative Physiology (ZIHP), University of Zurich, Zurich, Switzerland
| | - Max Gassmann
- Institute of Veterinary Physiology, Vetsuisse Faculty and Zurich Center Integrative Physiology (ZIHP), University of Zurich, Zurich, Switzerland
| | - Chih-Chieh Tsao
- Institute of Veterinary Physiology, Vetsuisse Faculty and Zurich Center Integrative Physiology (ZIHP), University of Zurich, Zurich, Switzerland
| | - Omolara O Ogunshola
- Institute of Veterinary Physiology, Vetsuisse Faculty and Zurich Center Integrative Physiology (ZIHP), University of Zurich, Zurich, Switzerland.
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Böttcher-Friebertshäuser E, Garten W, Klenk HD. The Antiviral Potential of Host Protease Inhibitors. ACTIVATION OF VIRUSES BY HOST PROTEASES 2018. [PMCID: PMC7122247 DOI: 10.1007/978-3-319-75474-1_11] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The replication of numerous pathogenic viruses depends on host proteases, which therefore emerged as potential antiviral drug targets. In some cases, e.g., for influenza viruses, their function during the viral propagation cycle is relatively well understood, where they cleave and activate viral surface glycoproteins. For other viruses, e.g., Ebola virus, the function of host proteases during replication is still not clear. Host proteases may also contribute to the pathogenicity of virus infection by activating proinflammatory cytokines. For some coronaviruses, human proteases can also serve in a nonproteolytical fashion simply as receptors for virus entry. However, blocking of such protein-protein contacts is challenging, because receptor surfaces are often flat and difficult to address with small molecules. In contrast, many proteases possess well-defined binding pockets. Therefore, they can be considered as well-druggable targets, especially, if they are extracellularly active. The number of their experimental crystal structures is steadily increasing, which is an important prerequisite for a rational structure-based inhibitor design using computational chemistry tools in combination with classical medicinal chemistry approaches. Moreover, host proteases can be considered as stable targets, and their inhibition should prevent rapid resistance developments, which is often observed when addressing viral proteins. Otherwise, the inhibition of host proteases can also affect normal physiological processes leading to a higher probability of side effects and a narrow therapeutic window. Therefore, they should be preferably used in combination therapies with additional antiviral drugs. This strategy should provide a stronger antiviral efficacy, allow to use lower drug doses, and minimize side effects. Despite numerous experimental findings on their antiviral activity, no small-molecule inhibitors of host proteases have been approved for the treatment of virus infections, so far.
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Affiliation(s)
| | - Wolfgang Garten
- Institut für Virologie, Philipps Universität, Marburg, Germany
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Yu Y, Lei X, Jiang H, Li Z, Creemers JWM, Zhang M, Qin S, Jin W, Jiang X. Prodomain of Furin Promotes Phospholipid Transfer Protein Proteasomal Degradation in Hepatocytes. J Am Heart Assoc 2018; 7:e008526. [PMID: 29680823 PMCID: PMC6015287 DOI: 10.1161/jaha.118.008526] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Accepted: 03/22/2018] [Indexed: 12/21/2022]
Abstract
BACKGROUND Phospholipid transfer protein (PLTP) is one of the major modulators of lipoprotein metabolism and atherosclerosis development; however, little is known about the regulation of PLTP. The effect of hepatic prodomain of furin (profurin) expression on PLTP processing and function is investigated. METHODS AND RESULTS We used adenovirus expressing profurin in mouse liver to evaluate PLTP activity, mass, and plasma lipid levels. We coexpressed PLTP and profurin in human hepatoma cell line cells and studied their interaction. We found profurin expression significantly reduced plasma lipids, plasma PLTP activity, and mass in all tested mouse models, compared with controls. Moreover, the expression of profurin dramatically reduced liver PLTP activity and protein level. We further explored the mechanism using in vivo and ex vivo approaches. We found that profurin can interact with intracellular PLTP and promote its ubiquitination and proteasomal degradation, resulting in less PLTP secretion from the hepatocytes. Furin does not cleave PLTP; instead, it forms a complex with PLTP, likely through its prodomain. CONCLUSIONS Our study reveals that hepatic PLTP protein is targeted for proteasomal degradation by profurin expression, which could be a novel posttranslational mechanism underlying PLTP regulation.
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Affiliation(s)
- Yang Yu
- Department of Cell BiologyState University of New York Downstate Medical CenterBrooklynNY
- Key Laboratory of Atherosclerosis in Universities of Shandong and Institute of AtherosclerosisTaishan Medical UniversityTaianChina
| | - Xia Lei
- Department of Cell BiologyState University of New York Downstate Medical CenterBrooklynNY
| | - Hui Jiang
- Department of Cell BiologyState University of New York Downstate Medical CenterBrooklynNY
| | - Zhiqiang Li
- Department of Cell BiologyState University of New York Downstate Medical CenterBrooklynNY
| | - John W. M. Creemers
- Laboratory of Biochemical NeuroendocrinologyDepartment of Human GeneticsHerestraat 49 bus 6023000 LeuvenBelgium
| | - Ming Zhang
- Department of Cell BiologyState University of New York Downstate Medical CenterBrooklynNY
| | - Shucun Qin
- Key Laboratory of Atherosclerosis in Universities of Shandong and Institute of AtherosclerosisTaishan Medical UniversityTaianChina
| | - Weijun Jin
- Department of Cell BiologyState University of New York Downstate Medical CenterBrooklynNY
| | - Xian‐Cheng Jiang
- Department of Cell BiologyState University of New York Downstate Medical CenterBrooklynNY
- Molecular and Cellular Cardiology ProgramVeterans Affair New York Harbor Healthcare SystemBrooklynNY
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Solovyeva NI, Gureeva TA, Timoshenko OS, Moskvitina TA, Kugaevskaya EV. Furin as proprotein convertase and its role in normal and pathological biological processes. BIOCHEMISTRY (MOSCOW), SUPPLEMENT SERIES B: BIOMEDICAL CHEMISTRY 2017. [DOI: 10.1134/s1990750817020081] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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15
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Klein-Szanto AJ, Bassi DE. Proprotein convertase inhibition: Paralyzing the cell's master switches. Biochem Pharmacol 2017; 140:8-15. [PMID: 28456517 DOI: 10.1016/j.bcp.2017.04.027] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Accepted: 04/25/2017] [Indexed: 12/18/2022]
Abstract
Proprotein convertases are serine proteases responsible for the cleavage and subsequent activation of protein substrates, many of them relevant for the development of an ample variety of diseases. Seven of the PCs, including furin and PACE4, recognize and hydrolyze the C-terminal end of the general sequence RXRR/KXR, whereas PCSK-9 recognizes a series of non-basic amino acids. In some systems, PC-mediated substrate activation results in the development of pathological processes, such as cancer, endocrinopathies, and cardiovascular and infectious diseases. After establishing PCs as relevant contributors to disease processes, research efforts were directed towards the development of inhibition strategies, including small and large molecules, anti-sense therapies, and antibody-based therapies. Most of these inhibitors mimic the consensus sequence of PCs, blocking the active site in a competitive manner. The most promising inhibitors were designed as bioengineered proteins; however, some non-protein and peptidomimetic agents have also proved to be effective. These efforts led to the design of pre-clinical studies and clinical trials utilizing inhibitors to PCs. Although the initial studies were performed using non-selective PCs inhibitors, such as CMK, the search for more specific, and compartmentalized selective inhibitors resulted in specific activities ascribed to some, but not all of the PCs. For instance, PACE4 inhibitors were effective in decreasing prostate cancer cell proliferation, and neovascularization. Decreased metastatic ovarian cancer utilizing furin inhibitors represents one of the major endeavors, currently in a phase II trial stage. Antibodies targeting PCSK-9 decreased significantly the levels of HDL-cholesterol, in a phase III trial. The study of Proprotein convertases has reached a stage of maturity. New strategies based on the alteration of their activity at the cellular and clinical level represent a promising experimental pharmacology field. The development of allosteric inhibitors, or specific agents directed against individual PCs is one of the challenges to be unraveled in the future.
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Affiliation(s)
| | - Daniel E Bassi
- Fox Chase Cancer Center, 333 Cotman Ave, Philadelphia 19111, USA.
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Stijnen P, Ramos-Molina B, O'Rahilly S, Creemers JWM. PCSK1 Mutations and Human Endocrinopathies: From Obesity to Gastrointestinal Disorders. Endocr Rev 2016; 37:347-71. [PMID: 27187081 DOI: 10.1210/er.2015-1117] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Prohormone convertase 1/3, encoded by the PCSK1 gene, is a serine endoprotease that is involved in the processing of a variety of proneuropeptides and prohormones. Humans who are homozygous or compound heterozygous for loss-of-function mutations in PCSK1 exhibit a variable and pleiotropic syndrome consisting of some or all of the following: obesity, malabsorptive diarrhea, hypogonadotropic hypogonadism, altered thyroid and adrenal function, and impaired regulation of plasma glucose levels in association with elevated circulating proinsulin-to-insulin ratio. Recently, more common variants in the PCSK1 gene have been found to be associated with alterations in body mass index, increased circulating proinsulin levels, and defects in glucose homeostasis. This review provides an overview of the endocrinopathies and other disorders observed in prohormone convertase 1/3-deficient patients, discusses the possible biochemical basis for these manifestations of the disease, and proposes a model whereby certain missense mutations in PCSK1 may result in proteins with a dominant negative action.
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Affiliation(s)
- Pieter Stijnen
- Laboratory for Biochemical Neuroendocrinology (P.S., B.R.-M., J.W.M.C.), Department of Human Genetics, KU Leuven, Leuven 3000, Belgium; and Medical Research Council (MRC) Metabolic Diseases Unit (S.O.), Wellcome Trust-MRC Institute of Metabolic Science, National Institute for Health Research, Cambridge Biomedical Research Centre, Addenbrooke's Hospital, University of Cambridge, Cambridge CB2 0QQ, United Kingdom
| | - Bruno Ramos-Molina
- Laboratory for Biochemical Neuroendocrinology (P.S., B.R.-M., J.W.M.C.), Department of Human Genetics, KU Leuven, Leuven 3000, Belgium; and Medical Research Council (MRC) Metabolic Diseases Unit (S.O.), Wellcome Trust-MRC Institute of Metabolic Science, National Institute for Health Research, Cambridge Biomedical Research Centre, Addenbrooke's Hospital, University of Cambridge, Cambridge CB2 0QQ, United Kingdom
| | - Stephen O'Rahilly
- Laboratory for Biochemical Neuroendocrinology (P.S., B.R.-M., J.W.M.C.), Department of Human Genetics, KU Leuven, Leuven 3000, Belgium; and Medical Research Council (MRC) Metabolic Diseases Unit (S.O.), Wellcome Trust-MRC Institute of Metabolic Science, National Institute for Health Research, Cambridge Biomedical Research Centre, Addenbrooke's Hospital, University of Cambridge, Cambridge CB2 0QQ, United Kingdom
| | - John W M Creemers
- Laboratory for Biochemical Neuroendocrinology (P.S., B.R.-M., J.W.M.C.), Department of Human Genetics, KU Leuven, Leuven 3000, Belgium; and Medical Research Council (MRC) Metabolic Diseases Unit (S.O.), Wellcome Trust-MRC Institute of Metabolic Science, National Institute for Health Research, Cambridge Biomedical Research Centre, Addenbrooke's Hospital, University of Cambridge, Cambridge CB2 0QQ, United Kingdom
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Solovyeva N, Gureeva T, Timoshenko O, Moskvitina T, Kugaevskaya E. Furin as proprotein convertase and its role in normal and pathological biological processes. ACTA ACUST UNITED AC 2016; 62:609-621. [DOI: 10.18097/pbmc20166206609] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Furin belongs to serine intracellular Ca2+-dependent endopeptidases of the subtilisin family, also known as proprotein convertase (PC). Human furin is synthesized as zymogen with a molecular weight of 104 kDa, which is then activated by autocatalytic in two stages. This process can occur when zymogen migrates from the endoplasmic reticulum to the Golgi apparatus, where a large part of furin is accumulated. The molecular weigh t of the active furin is 98 kDa. Furin relates to enzymes with a narrow substrate specificity: it hydrolyzes peptide bonds at the site of paired basic amino acids and furin activity exhibits in a wide pH range 5-8. Its main biological function is activation of the functionally important protein precursors. It is accompanied by the launch of a cascade of reactions, which lead to appearance of biologically active molecules involved in realization of specific biological functions both in normal and in some patologicheskih processes. Furin substrates are biologically important proteins such as enzymes, hormones, growth factors and differentiation, receptors, adhesion proteins, proteins of blood plasma. Furin plays an important role in the development of processes such as proliferation, invasion, cell migration, survival, maintenance of homeostasis, embryogenesis, as well as the development of a number of pathologies, including cardiovascular, oncologic and neurodegenerative diseases. Furin and furin-like proprotein convertases participate as key factors in the realization of the regulatory functions of proteolytic enzymes, the value of which is currently being evaluated as most important in comparison with the degradative function of proteases.
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Affiliation(s)
| | - T.A. Gureeva
- Institute of Biomedical Chemistry, Moscow, Russia
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Demidyuk IV, Shubin AV, Gasanov EV, Kostrov SV. Propeptides as modulators of functional activity of proteases. Biomol Concepts 2015; 1:305-22. [PMID: 25962005 DOI: 10.1515/bmc.2010.025] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Most proteases are synthesized in the cell as precursor-containing propeptides. These structural elements can determine the folding of the cognate protein, function as an inhibitor/activator peptide, mediate enzyme sorting, and mediate the protease interaction with other molecules and supramolecular structures. The data presented in this review demonstrate modulatory activity of propeptides irrespective of the specific mechanism of action. Changes in propeptide structure, sometimes minor, can crucially alter protein function in the living organism. Modulatory activity coupled with high variation allows us to consider propeptides as specific evolutionary modules that can transform biological properties of proteases without significant changes in the highly conserved catalytic domains. As the considered properties of propeptides are not unique to proteases, propeptide-mediated evolution seems to be a universal biological mechanism.
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Is there a link between proprotein convertase PC7 activity and human lipid homeostasis? FEBS Open Bio 2014; 4:741-5. [PMID: 25349778 PMCID: PMC4208093 DOI: 10.1016/j.fob.2014.08.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Revised: 08/08/2014] [Accepted: 08/26/2014] [Indexed: 11/23/2022] Open
Abstract
A R504H mutation in human proprotein convertase PC7 is associated with increased HDL and reduced triglycerides. Wild-type PC7 and its R504H mutant have identical cellular enzymatic activities. In situ hybridization revealed co-localization of mouse ApoF and PC7 mRNAs in liver. WT and PC7 KO mice do not exhibit changes in circulating levels of insulin or glucose. WT and PC7 KO mice do not exhibit changes in circulating levels of HDL, TG and LDL.
A genome-wide association study suggested that a R504H mutation in the proprotein convertase PC7 is associated with increased circulating levels of HDL and reduced triglycerides in black Africans. Our present results show that PC7 and PC7-R504H exhibit similar processing of transferrin receptor-1, proSortilin, and apolipoprotein-F. Plasma analyses revealed no change in the lipid profiles, insulin or glucose of wild type and PC7 KO mice. Thus, the R504H mutation does not modify the proteolytic activity of PC7. The mechanisms behind the implication of PC7 in the regulation of human HDL, triglycerides and in modifying the levels of atherogenic small dense LDL remain to be elucidated.
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Key Words
- ANGPTL3, angiopoietin-like 3
- ANGPTL4, angiopoietin-like 4
- ApoF, apolipoprotein-F
- Apolipoprotein F
- GOF, gain of function
- GWAS, genome-wide association study
- HDL, high-density lipoprotein
- HDL/LDL
- KO, knockout
- LDL, low-density lipoprotein
- PCs, proprotein convertases
- Proprotein convertase PC7
- SNP, single nucleotide polymorphism
- Sortilin
- TGN, trans Golgi network
- TMD, transmembrane domain
- Transferrin receptor 1
- Triglycerides
- VLDL, very low-density lipoprotein
- hTfR1, human PC7-substrates: transferrin receptor 1
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Hepatic overexpression of the prodomain of furin lessens progression of atherosclerosis and reduces vascular remodeling in response to injury. Atherosclerosis 2014; 236:121-30. [PMID: 25026302 DOI: 10.1016/j.atherosclerosis.2014.06.015] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/26/2013] [Revised: 06/16/2014] [Accepted: 06/18/2014] [Indexed: 11/24/2022]
Abstract
OBJECTIVE Atherosclerosis is a complex disease, involving elevated LDL-c, lipid accumulation in the blood vessel wall, foam cell formation and vascular dysfunction. Lowering plasma LDL-c is the cornerstone of current management of cardiovascular disease. However, new approaches which reduce plasma LDL-c and lessen the pathological vascular remodeling occurring in the disease should also have therapeutic value. Previously, we found that overexpression of profurin, the 83-amino acid prodomain of the proprotein convertase furin, lowered plasma HDL levels in wild-type mice. The question that remained was whether it had effects on apolipoprotein B (ApoB)-containing lipoproteins. METHODS Adenovirus mediated overexpression of hepatic profurin in Ldlr(-/-)mice and wild-type mice were used to evaluate effects of profurin on ApoB-containing lipoproteins, atherosclerosis and vascular remodeling. RESULTS Hepatic profurin overexpression resulted in a significant reduction in atherosclerotic lesion development in Ldlr(-/-)mice and a robust reduction in plasma LDL-c. Metabolic studies revealed lower secretion of ApoB and triglycerides in VLDL particles. Mechanistic studies showed that in the presence of profurin, hepatic ApoB, mainly ApoB100, was degraded by proteasomes. There was no effect on ApoB mRNA expression. Importantly, short-term hepatic profurin overexpression did not result in hepatic lipid accumulation. Blood vessel wall thickening caused by either wire-induced femoral artery injury or common carotid artery ligation was reduced. Profurin expression inhibited proliferation and migration in vascular smooth muscle cells in vitro. CONCLUSION These results indicate that a profurin-based therapy has the potential to treat atherosclerosis by improving metabolic lipid profiles and reducing both atherosclerotic lesion development and pathological vascular remodeling.
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Polyphenols as therapeutic molecules in Alzheimer's disease through modulating amyloid pathways. Mol Neurobiol 2014; 51:466-79. [PMID: 24826916 DOI: 10.1007/s12035-014-8722-9] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Accepted: 04/17/2014] [Indexed: 02/07/2023]
Abstract
Alzheimer's disease (AD) is a complex and multifactorial neurodegenerative condition. The complex pathology of this disease includes oxidative stress, metal deposition, formation of aggregates of amyloid and tau, enhanced immune responses, and disturbances in cholinesterase. Drugs targeted toward reduction of amyloidal load have been discovered, but there is no effective pharmacological treatment for combating the disease so far. Natural products have become an important avenue for drug discovery research. Polyphenols are natural products that have been shown to be effective in the modulation of the type of neurodegenerative changes seen in AD, suggesting a possible therapeutic role. The present review focuses on the chemistry of polyphenols and their role in modulating amyloid precursor protein (APP) processing. We also provide new hypotheses on how these therapeutic molecules may modulate APP processing, prevent Aβ aggregation, and favor disruption of preformed fibrils. Finally, the role of polyphenols in modulating Alzheimer's pathology is discussed.
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Proteomics-based identification of plasma proteins and their association with the host-pathogen interaction in chronic typhoid carriers. Int J Infect Dis 2013; 19:59-66. [PMID: 24291468 PMCID: PMC7129176 DOI: 10.1016/j.ijid.2013.10.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Revised: 10/08/2013] [Accepted: 10/09/2013] [Indexed: 01/03/2023] Open
Abstract
Background Current diagnostic tests are inadequate to detect typhoid cases, as well as the chronic carrier state, the sole reservoir of Salmonella enterica serovar Typhi. The current study was conducted to find new molecular signatures of pathogen/disease to understand the mechanism behind the host–pathogen interaction in enteric fever. Methods Proteomics-based studies were done to determine the expression of differentially expressed proteins in the plasma of controls, acute typhoid cases, and chronic typhoid carriers. Further, transcriptome-based analysis using reverse-transcriptase PCR (RT-PCR) was done in controls, acute typhoid cases, and chronic typhoid carriers. Results Results showed the upregulation of proprotein convertase subtilisin, furin, haptoglobin, and albumin in the plasma of chronic typhoid carriers. The elevation in mRNA expression of four differentially expressed proteins confirms the changes at the transcriptional level. Further, the increase in albumin and haptoglobin in chronic typhoid carriers shows their role in free radical generation, inflammation, and monocyte cell signaling. Conclusion Through proteomics techniques, this study identified four proteins in the chronic typhoid carrier host that may have a role in the disease pathogenesis of enteric fever.
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Hipp MM, Shepherd D, Gileadi U, Aichinger MC, Kessler BM, Edelmann MJ, Essalmani R, Seidah NG, Reis e Sousa C, Cerundolo V. Processing of human toll-like receptor 7 by furin-like proprotein convertases is required for its accumulation and activity in endosomes. Immunity 2013; 39:711-21. [PMID: 24138882 PMCID: PMC4839496 DOI: 10.1016/j.immuni.2013.09.004] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2012] [Accepted: 07/25/2013] [Indexed: 11/18/2022]
Abstract
Toll-like receptor 7 (TLR7) triggers antiviral immune responses by recognizing viral single-stranded RNA in endosomes, but the biosynthetic pathway of human TLR7 (hTLR7) remains unclear. Here, we show that hTLR7 is proteolytically processed and that the C-terminal fragment selectively accumulates in endocytic compartments. hTLR7 processing occurred at neutral pH and was dependent on furin-like proprotein convertases (PCs). Furthermore, TLR7 processing was required for its functional response to TLR7 agonists such as R837 or influenza virus. Notably, proinflammatory and differentiation stimuli increased the expression of furin-like PCs in immune cells, suggesting a positive feedback mechanism for TLR7 processing during infection. Because self-RNA can under certain conditions activate TLR7 and trigger autoimmunity, our results identify furin-like PCs as a possible target to attenuate TLR7-dependent autoimmunity and other immune pathologies.
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Affiliation(s)
- Madeleine M Hipp
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DU, UK
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Scamuffa N, Sfaxi F, Ma J, Lalou C, Seidah N, Calvo F, Khatib AM. Prodomain of the proprotein convertase subtilisin/kexin Furin (ppFurin) protects from tumor progression and metastasis. Carcinogenesis 2013; 35:528-36. [PMID: 24127186 DOI: 10.1093/carcin/bgt345] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Proteolytic maturation of various precursor proteins by the proprotein convertase Furin is now considered as a crucial step in tumor progression and metastasis. Here, we report the repression of the malignant and metastatic potential of carcinoma cells by the prodomain region of Furin (ppFurin), a naturally occurring inhibitor of this convertase. Overexpression of ppFurin in carcinoma cells in a stable manner significantly reduced their convertase activity and ability to mediate processing of the Furin cancer-related substrates platelet-derived growth factor (PDGF)-A and insulin-like growth factor-I receptor precursors. Unprocessed platelet-derived growth factor-A produced by ppFurin expressing cells failed to induce the activation of Akt in the platelet-derived growth factor receptor-expressing cells NIH BALB/c-3T3 and treatment of ppFurin expressing cells with insulin-like growth factor-I failed to induce Akt phosphorylation, compared with controls. The malignant potential of ppFurin expressing cells was significantly reduced as revealed by the loss of anchorage-independent growth and survival that associated their increased chemosensitivity. In vivo, comparative studies revealed that expression of ppFurin in the carcinoma cells MDA-MB-231 and CT-26 cells inhibited tumor growth when subcutaneously inoculated in nude mice. The use of an experimental liver colorectal metastasis model revealed the reduced ability of metastatic carcinoma CT-26 cells to colonize the liver in response to intrasplenic/portal inoculation. Further analyses revealed reduced Furin activity in tumors derived from intrasplenic inoculated mice with ppFurin expressing CT-26 cells. This finding highlights the role of Furin in the malignant and metastatic potential of tumor cells and suggests the possible consideration of using its naturally occurring inhibitor ppFurin in anticancer therapy.
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Luna Saavedra YG, Zhang J, Seidah NG. PCSK9 prosegment chimera as novel inhibitors of LDLR degradation. PLoS One 2013; 8:e72113. [PMID: 23951290 PMCID: PMC3741231 DOI: 10.1371/journal.pone.0072113] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Accepted: 07/09/2013] [Indexed: 12/23/2022] Open
Abstract
The proprotein convertase PCSK9, a target for the treatment of hypercholesterolemia, is a negative regulator of the LDL receptor (LDLR) leading to its degradation in endosomes/lysosomes and up-regulation of plasma LDL-cholesterol levels. The proprotein convertases, a family of nine secretory serine proteases, are first synthesized as inactive zymogens. Except for PCSK9, all other convertases are activated following the autocatalytic excision of their inhibitory N-terminal prosegment. PCSK9 is unique since the mature enzyme exhibits a cleaved prosegment complexed with the catalytic subunit and has no protease activity towards other substrates. Similar to other convertases, we hypothesized that the in trans presence of the PCSK9 prosegment would interfere with PCSK9's activity on the LDLR. Since the prosegment cannot be secreted alone, we engineered a chimeric protein using the Fc-region of human IgG1 fused to the PCSK9 prosegment. The expression of such Fcpro-fusion protein in HEK293 and HepG2 cells resulted in a secreted protein that binds PCSK9 and markedly inhibits its activity on the LDLR. This was observed by either intracellular co-expression of PCSK9 and Fcpro or by an extracellular in vitro co-incubation of Fcpro with PCSK9. Structure-function studies revealed that the inhibitory function of Fcpro does not require the acidic N-terminal stretch (residues 31–58) nor the C-terminal Gln152 of the prosegment. Fcpro likely interacts with the prosegment and/or catalytic subunit of the prosegment≡PCSK9 complex thereby allosterically modulating its function. Our data suggest a novel strategic approach for the design and isolation of PCSK9 inhibitors.
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Affiliation(s)
- Yascara Grisel Luna Saavedra
- Laboratory of Biochemical Neuroendocrinology, Clinical Research Institute of Montreal, affiliated to the Université de Montréal, Montréal, Québec, Canada
| | - Jianbing Zhang
- Institute for Biological Sciences, National Research Council Canada, Ottawa, Ontario, Canada
| | - Nabil G. Seidah
- Laboratory of Biochemical Neuroendocrinology, Clinical Research Institute of Montreal, affiliated to the Université de Montréal, Montréal, Québec, Canada
- * E-mail:
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Essalmani R, Susan-Resiga D, Chamberland A, Asselin MC, Canuel M, Constam D, Creemers JW, Day R, Gauthier D, Prat A, Seidah NG. Furin is the primary in vivo convertase of angiopoietin-like 3 and endothelial lipase in hepatocytes. J Biol Chem 2013; 288:26410-8. [PMID: 23918928 DOI: 10.1074/jbc.m113.501304] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The proprotein convertases (PCs) furin, PC5/6, and PACE4 exhibit unique and/or complementary functions. Their knock-out (KO) in mice resulted in strong and specific phenotypes demonstrating that, in vivo, these PCs are unique and essential during development. However, they also exhibit redundant functions. Liver angiopoietin-like 3 (ANGPTL3) inhibits lipolysis by binding to lipoprotein lipases. It is found in the plasma as full length and truncated forms. The latter is more active and generated by cleavage at a furin-like site. Endothelial lipase (EL) binds heparin sulfate proteoglycans on cell surfaces and catalyzes the hydrolysis of HDL phospholipids. EL activity is regulated by two endogenous inhibitors, ANGPTL3 and ANGPTL4, and by PCs that inactivate EL through cleavage releasing the N-terminal catalytic and C-terminal lipid-binding domains. Herein, because furin and PC5/6 complete KOs are lethal, we used mice lacking furin or PC5/6 specifically in hepatocytes (hKO) or mice completely lacking PACE4. In primary hepatocytes, ANGPTL3 was processed into a shorter form of ANGPTL3 intracellularly by furin only, and extracellularly mainly by PACE4. In vivo, the absence of furin in hepatocytes reduced by ∼50% the circulating levels of cleaved ANGPTL3, while the lack of PACE4 had only a minor effect. Analysis of the EL processing in primary hepatocytes and in vivo revealed that it is mostly cleaved by furin. However, the lack of furin or PC5/6 in hepatocytes and complete PACE4 KO did not appreciably modify plasma HDL levels or EL activity. Thus, inhibition of furin in liver would not be expected to modify the plasma lipid profiles.
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Pasquato A, Ramos da Palma J, Galan C, Seidah NG, Kunz S. Viral envelope glycoprotein processing by proprotein convertases. Antiviral Res 2013; 99:49-60. [PMID: 23611717 DOI: 10.1016/j.antiviral.2013.04.013] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2013] [Revised: 04/09/2013] [Accepted: 04/14/2013] [Indexed: 01/03/2023]
Abstract
The proprotein convertases (PCs) are a family of nine mammalian enzymes that play key roles in the maintenance of cell homeostasis by activating or inactivating proteins via limited proteolysis under temporal and spatial control. A wide range of pathogens, including major human pathogenic viruses can hijack cellular PCs for their own purposes. In particular, productive infection with many enveloped viruses critically depends on the processing of their fusion-active viral envelope glycoproteins by cellular PCs. Based on their crucial role in virus-host interaction, PCs can be important determinants for viral pathogenesis and represent promising targets of therapeutic antiviral intervention. In the present review we will cover basic aspects and recent developments of PC-mediated maturation of viral envelope glycoproteins of selected medically important viruses. The molecular mechanisms underlying the recognition of PCs by viral glycoproteins will be described, including recent findings demonstrating differential PC-recognition of viral and cellular substrates. We will further discuss a possible scenario how viruses during co-evolution with their hosts adapted their glycoproteins to modulate the activity of cellular PCs for their own benefit and discuss the consequences for virus-host interaction and pathogenesis. Particular attention will be given to past and current efforts to evaluate cellular PCs as targets for antiviral therapeutic intervention, with emphasis on emerging highly pathogenic viruses for which no efficacious drugs or vaccines are currently available.
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Affiliation(s)
- Antonella Pasquato
- Institute of Microbiology, University Hospital Center and University of Lausanne, Lausanne CH-1011, Switzerland.
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Non-peptide furin inhibitors based on amidinohydrazones of diarylaldehydes. UKRAINIAN BIOCHEMICAL JOURNAL 2013; 85:22-32. [DOI: 10.15407/ubj85.01.022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Levesque C, Fugère M, Kwiatkowska A, Couture F, Desjardins R, Routhier S, Moussette P, Prahl A, Lammek B, Appel JR, Houghten RA, D'Anjou F, Dory YL, Neugebauer W, Day R. The Multi-Leu peptide inhibitor discriminates between PACE4 and furin and exhibits antiproliferative effects on prostate cancer cells. J Med Chem 2012; 55:10501-11. [PMID: 23126600 PMCID: PMC3523546 DOI: 10.1021/jm3011178] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
![]()
The proprotein convertases (PCs) play an important role
in protein precursor activation
through processing at paired basic residues. However, significant
substrate cleavage redundancy has been reported between PCs. The question
remains whether specific PC inhibitors can be designed. This study
describes the identification of the sequence LLLLRVKR, named Multi-Leu
(ML)-peptide, that displayed a 20-fold selectivity on PACE4 over furin,
two enzymes with similar structural characteristics. We have previously
demonstrated that PACE4 plays an important role in prostate cancer
and could be a druggable target. The present study demonstrates that
the ML-peptide significantly reduced the proliferation of DU145 and
LNCaP prostate cancer-derived cell lines and induced G0/G1 cell cycle arrest. However, the ML-peptide must enter
the cell to inhibit proliferation. It is concluded that peptide-based
inhibitors can yield specific PC inhibitors and that the ML-peptide
is an important lead compound that could potentially have applications
in prostate cancer.
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Affiliation(s)
- Christine Levesque
- Institut de Pharmacologie de Sherbrooke, Département de Chirurgie/Urologie, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, 3001 12e Avenue Nord, Sherbrooke, Québec J1H 5N4, Canada
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Benjannet S, Hamelin J, Chrétien M, Seidah NG. Loss- and gain-of-function PCSK9 variants: cleavage specificity, dominant negative effects, and low density lipoprotein receptor (LDLR) degradation. J Biol Chem 2012; 287:33745-55. [PMID: 22875854 DOI: 10.1074/jbc.m112.399725] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The proprotein convertase PCSK9 is a major target in the treatment of hypercholesterolemia because of its ability bind the LDL receptor (LDLR) and enhance its degradation in endosomes/lysosomes. In the endoplasmic reticulum, the zymogen pro-PCSK9 is first autocatalytically cleaved at its internal Gln(152)↓, resulting in a secreted enzymatically inactive complex of PCSK9 with its inhibitory prosegment (prosegment·PCSK9), which is the active form of PCSK9 on the LDLR. We mutagenized the P1 cleavage site Gln(152) into all other residues except Cys and analyzed the expression and secretion of the resulting mutants. The data demonstrated the following. 1) The only P1 residues recognized by PCSK9 are Gln > Met > Ala > Ser > Thr ≈ Asn, revealing an unsuspected specificity. 2) All other mutations led to the formation of an unprocessed zymogen that acted as a dominant negative retaining the native protein in the endoplasmic reticulum. Analysis of a large panoply of known natural and artificial point mutants revealed that this general dominant negative observation applies to all PCSK9 mutations that result in the inability of the protein to exit the endoplasmic reticulum. Such a tight quality control property of the endoplasmic reticulum may lead to the development of specific PCSK9 small molecule inhibitors that block its autocatalytic processing. Finally, inspired by the most active gain-of-function mutant, D374Y, we evaluated the LDLR degradation activity of 18 Asp(374) variants of PCSK9. All Asp(374) mutations resulted in similar gain-of-function activity on the LDLR except that D374E was as active as native PCSK9, D374G was relatively less active, and D374N and D374P were completely inactive.
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Affiliation(s)
- Suzanne Benjannet
- Laboratory of Biochemical Neuroendocrinology, University of Montreal, Montreal, Quebec, Canada
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Seidah NG, Prat A. The biology and therapeutic targeting of the proprotein convertases. Nat Rev Drug Discov 2012; 11:367-83. [PMID: 22679642 DOI: 10.1038/nrd3699] [Citation(s) in RCA: 588] [Impact Index Per Article: 49.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The mammalian proprotein convertases constitute a family of nine secretory serine proteases that are related to bacterial subtilisin and yeast kexin. Seven of these (proprotein convertase 1 (PC1), PC2, furin, PC4, PC5, paired basic amino acid cleaving enzyme 4 (PACE4) and PC7) activate cellular and pathogenic precursor proteins by cleavage at single or paired basic residues, whereas subtilisin kexin isozyme 1 (SKI-1) and proprotein convertase subtilisin kexin 9 (PCSK9) regulate cholesterol and/or lipid homeostasis via cleavage at non-basic residues or through induced degradation of receptors. Proprotein convertases are now considered to be attractive targets for the development of powerful novel therapeutics. In this Review, we summarize the physiological functions and pathological implications of the proprotein convertases, and discuss proposed strategies to control some of their activities, including their therapeutic application and validation in selected disease states.
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Affiliation(s)
- Nabil G Seidah
- Laboratory of Biochemical Neuroendocrinology, Clinical Research Institute of Montreal (affiliated to University of Montreal), 110 Pine Ave West, Montreal, Quebec H2W 1R7, Canada.
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Burri DJ, Pasqual G, Rochat C, Seidah NG, Pasquato A, Kunz S. Molecular characterization of the processing of arenavirus envelope glycoprotein precursors by subtilisin kexin isozyme-1/site-1 protease. J Virol 2012; 86:4935-46. [PMID: 22357276 PMCID: PMC3347368 DOI: 10.1128/jvi.00024-12] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2012] [Accepted: 02/14/2012] [Indexed: 01/27/2023] Open
Abstract
A crucial step in the life cycle of arenaviruses is the biosynthesis of the mature fusion-active viral envelope glycoprotein (GP) that is essential for virus-host cell attachment and entry. The maturation of the arenavirus GP precursor (GPC) critically depends on proteolytic processing by the cellular proprotein convertase (PC) subtilisin kexin isozyme-1 (SKI-1)/site-1 protease (S1P). Here we undertook a molecular characterization of the SKI-1/S1P processing of the GPCs of the prototypic arenavirus lymphocytic choriomeningitis virus (LCMV) and the pathogenic Lassa virus (LASV). Previous studies showed that the GPC of LASV undergoes processing in the endoplasmic reticulum (ER)/cis-Golgi compartment, whereas the LCMV GPC is cleaved in a late Golgi compartment. Herein we confirm these findings and provide evidence that the SKI-1/S1P recognition site RRLL, present in the SKI-1/S1P prodomain and LASV GPC, but not in the LCMV GPC, is crucial for the processing of the LASV GPC in the ER/cis-Golgi compartment. Our structure-function analysis revealed that the cleavage of arenavirus GPCs, but not cellular substrates, critically depends on the autoprocessing of SKI-1/S1P, suggesting differences in the processing of cellular and viral substrates. Deletion mutagenesis showed that the transmembrane and intracellular domains of SKI-1/S1P are dispensable for arenavirus GPC processing. The expression of a soluble form of the protease in SKI-I/S1P-deficient cells resulted in the efficient processing of arenavirus GPCs and rescued productive virus infection. However, exogenous soluble SKI-1/S1P was unable to process LCMV and LASV GPCs displayed at the surface of SKI-I/S1P-deficient cells, indicating that GPC processing occurs in an intracellular compartment. In sum, our study reveals important differences in the SKI-1/S1P processing of viral and cellular substrates.
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Affiliation(s)
- Dominique J. Burri
- Institute of Microbiology, University Hospital Center and University of Lausanne, Lausanne, Switzerland
| | - Giulia Pasqual
- Institute of Microbiology, University Hospital Center and University of Lausanne, Lausanne, Switzerland
| | - Cylia Rochat
- Institute of Microbiology, University Hospital Center and University of Lausanne, Lausanne, Switzerland
| | - Nabil G. Seidah
- Laboratory of Biochemical Neuroendocrinology, Clinical Research Institute of Montreal, Montreal, Canada
| | - Antonella Pasquato
- Institute of Microbiology, University Hospital Center and University of Lausanne, Lausanne, Switzerland
| | - Stefan Kunz
- Institute of Microbiology, University Hospital Center and University of Lausanne, Lausanne, Switzerland
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Abstract
The proprotein convertases (PCs) are secretory mammalian serine proteinases related to bacterial subtilisin-like enzymes. The family of PCs comprises nine members, PC1/3, PC2, furin, PC4, PC5/6, PACE4, PC7, SKI-1/S1P, and PCSK9 (Fig. 3.1). While the first seven PCs cleave after single or paired basic residues, the last two cleave at non-basic residues and the last one PCSK9 only cleaves one substrate, itself, for its activation. The targets and substrates of these convertases are very varied covering many aspects of cellular biology and communication. While it took more than 22 years to begin to identify the first member in 1989-1990, in less than 14 years they were all characterized. So where are we 20 years later in 2011? We have now reached a level of maturity needed to begin to unravel the mechanisms behind the complex physiological functions of these PCs both in health and disease states. We are still far away from comprehensively understanding the various ramifications of their roles and to identify their physiological substrates unequivocally. How do these enzymes function in vivo? Are there other partners to be identified that would modulate their activity and/or cellular localization? Would non-toxic inhibitors/silencers of some PCs provide alternative therapies to control some pathologies and improve human health? Are there human SNPs or mutations in these PCs that correlate with disease, and can these help define the finesses of their functions and/or cellular sorting? The more we know about a given field, the more questions will arise, until we are convinced that we have cornered the important angles. And yet the future may well reserve for us many surprises that may allow new leaps in our understanding of the fascinating biology of these phylogenetically ancient eukaryotic proteases (Fig. 3.2) implicated in health and disease, which traffic through the cells via multiple sorting pathways (Fig. 3.3).
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Affiliation(s)
- Nabil G Seidah
- Biochemical Neuroendocrinology Laboratory, Clinical Research Institute of Montreal, Montreal, QC, Canada H2W 1R7.
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Tassew N, Charish J, Seidah N, Monnier P. SKI-1 and Furin Generate Multiple RGMa Fragments that Regulate Axonal Growth. Dev Cell 2012; 22:391-402. [DOI: 10.1016/j.devcel.2011.11.022] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2011] [Revised: 09/19/2011] [Accepted: 11/21/2011] [Indexed: 11/26/2022]
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Iamsaard S, Vanichviriyakit R, Hommalai G, Saewu A, Srakaew N, Withyachumnarnkul B, Basak A, Tanphaichitr N. Enzymatic activity of sperm proprotein convertase is important for mammalian fertilization. J Cell Physiol 2011; 226:2817-26. [DOI: 10.1002/jcp.22626] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Sun X, Essalmani R, Susan-Resiga D, Prat A, Seidah NG. Latent transforming growth factor beta-binding proteins-2 and -3 inhibit the proprotein convertase 5/6A. J Biol Chem 2011; 286:29063-29073. [PMID: 21700711 DOI: 10.1074/jbc.m111.242479] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
The basic amino acid-specific proprotein convertase 5/6 (PC5/6) is an essential secretory protease, as knock-out mice die at birth and exhibit multiple homeotic transformation defects, including impaired bone morphogenesis and lung structure. Some of the observed defects were attributed to impaired processing of the TGFβ-like growth differentiating factor 11 precursor (proGdf11). In this work we present evidence that the latent TGFβ-binding proteins 2 and 3 (LTBP-2 and -3) inhibit the extracellular processing of proGdf11 by PC5/6A. This is partly due to the binding of LTBPs in the endoplasmic reticulum to the zymogen proPC5/6A, thus allowing the complex to exit the endoplasmic reticulum and be sequestered as an inactive zymogen in the extracellular matrix but not at the cell surface. This results in lower levels of PC5/6A in the media, without affecting those of PACE4, Furin, or a soluble form of PC7. The secreted soluble protease-specific activity of PC5/6A or a variant lacking the C-terminal Cys-rich domain (PC5/6-ΔCRD) is significantly decreased when co-expressed with LTBPs in cells. A similar enzymatic inhibition seems to apply to PACE4 and Furin. In situ hybridization analyses revealed extensive co-localization of PC5/6 and LTBP-3 mRNAs in mice at embryonic day 15.5 and post partum day 1. In conclusion, this is the first time that a zymogen of the proprotein convertases was shown to exit the endoplasmic reticulum in the presence of LTBPs, representing a potential novel mechanism for the regulation of PC5/6A activity, e.g. in tissues such as bone and lung where LTBP-3 and PC5/6 co-localize.
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Affiliation(s)
- Xiaowei Sun
- Laboratory of Biochemical Neuroendocrinology, Clinical Research Institute of Montreal, Montreal, Quebec H2W 1R7, Canada
| | - Rachid Essalmani
- Laboratory of Biochemical Neuroendocrinology, Clinical Research Institute of Montreal, Montreal, Quebec H2W 1R7, Canada
| | - Delia Susan-Resiga
- Laboratory of Biochemical Neuroendocrinology, Clinical Research Institute of Montreal, Montreal, Quebec H2W 1R7, Canada
| | - Annik Prat
- Laboratory of Biochemical Neuroendocrinology, Clinical Research Institute of Montreal, Montreal, Quebec H2W 1R7, Canada
| | - Nabil G Seidah
- Laboratory of Biochemical Neuroendocrinology, Clinical Research Institute of Montreal, Montreal, Quebec H2W 1R7, Canada.
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Susan-Resiga D, Essalmani R, Hamelin J, Asselin MC, Benjannet S, Chamberland A, Day R, Szumska D, Constam D, Bhattacharya S, Prat A, Seidah NG. Furin is the major processing enzyme of the cardiac-specific growth factor bone morphogenetic protein 10. J Biol Chem 2011; 286:22785-94. [PMID: 21550985 DOI: 10.1074/jbc.m111.233577] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Bone morphogenetic protein 10 (BMP10) is a member of the TGF-β superfamily and plays a critical role in heart development. In the postnatal heart, BMP10 is restricted to the right atrium. The inactive pro-BMP10 (∼60 kDa) is processed into active BMP10 (∼14 kDa) by an unknown protease. Proteolytic cleavage occurs at the RIRR(316)↓ site (human), suggesting the involvement of proprotein convertase(s) (PCs). In vitro digestion of a 12-mer peptide encompassing the predicted cleavage site with furin, PACE4, PC5/6, and PC7, showed that furin cleaves the best, whereas PC7 is inactive on this peptide. Ex vivo studies in COS-1 cells, a cell line lacking PC5/6, revealed efficient processing of pro-BMP10 by endogenous PCs other than PC5/6. The lack of processing of overexpressed pro-BMP10 in the furin- and PACE4-deficient cell line, CHO-FD11, and in furin-deficient LoVo cells, was restored by stable (CHO-FD11/Fur cells) or transient (LoVo cells) expression of furin. Use of cell-permeable and cell surface inhibitors suggested that endogenous PCs process pro-BMP10 mostly intracellularly, but also at the cell surface. Ex vivo experiments in mouse primary hepatocytes (wild type, PC5/6 knock-out, and furin knock-out) corroborated the above findings that pro-BMP10 is a substrate for endogenous furin. Western blot analyses of heart right atria extracts from wild type and PACE4 knock-out adult mice showed no significant difference in the processing of pro-BMP10, implying no in vivo role of PACE4. Overall, our in vitro, ex vivo, and in vivo data suggest that furin is the major convertase responsible for the generation of BMP10.
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Affiliation(s)
- Delia Susan-Resiga
- Laboratory of Biochemical Neuroendocrinology, Clinical Research Institute of Montreal, Université de Montréal, Montreal, Quebec H2W 1R7, Canada
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Zandberg WF, Benjannet S, Hamelin J, Pinto BM, Seidah NG. N-glycosylation controls trafficking, zymogen activation and substrate processing of proprotein convertases PC1/3 and subtilisin kexin isozyme-1. Glycobiology 2011; 21:1290-300. [PMID: 21527438 DOI: 10.1093/glycob/cwr060] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
The limited proteolysis of proteins by the proprotein convertases (PCs) is a common means of producing bioactive proteins or peptides. The PCs are associated with numerous human pathologies and their activity can be reduced through the use of specific inhibitors. Here, we demonstrate an alternative approach to inhibiting PCs by altering their N-glycosylation. Through site-directed mutagenesis, we show that the convertase PC1/3 contains two N-glycans, only one of which is critical for its prosegment cleavage. The exact structure of PC1/3 N-glycans does not significantly affect its zymogen activation within endocrine cells, but glycosylation of Asn(146) is critical. Processing of the PC1/3's substrate proopiomelanocortin (POMC) was used in a cell-based assay to screen a collection of 45 compounds structurally related to known glycosidase inhibitors. Two 5-thiomannose-containing disaccharide derivatives were discovered to block PC1/3 and POMC processing into the analgesic peptide β-endorphin. These compounds also reduced the zymogen activation of the convertase subtilisin kexin isozyme-1 (SKI-1), blocked the processing of its substrate the sterol regulatory element-binding protein SREBP-2 and altered its glycosylation. Thus, modification of PC glycosylation may also be a means of blocking their activity, an effect which, in the case of SKI-1, may be of possible therapeutic use since SREBP-2 regulates sterol levels including cholesterol biosynthesis and its metabolism.
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Affiliation(s)
- Wesley F Zandberg
- Department of Chemistry, Simon Fraser University, Burnaby, BC, Canada V5A 1S6
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Rousselet E, Benjannet S, Hamelin J, Canuel M, Seidah NG. The proprotein convertase PC7: unique zymogen activation and trafficking pathways. J Biol Chem 2011; 286:2728-38. [PMID: 21075846 PMCID: PMC3024769 DOI: 10.1074/jbc.m110.192344] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2010] [Revised: 11/09/2010] [Indexed: 01/04/2023] Open
Abstract
The zymogen activation mechanism and physiological functions of the most ancient and highly conserved basic amino acid-specific proprotein convertase 7 (PC7) are not known. Herein, we characterized the biosynthesis, subcellular localization, and trafficking of the membrane-bound full-length rat and human PC7. The prosegment of PC7 is primarily secreted alone as a non-inhibitory protein via the conventional, Golgi-dependent, secretory pathway. Mature PC7 is partially sulfated and thus reaches the cell surface via the conventional route. However, a fraction of PC7 reaches the cell surface through a brefeldin A- and COPII-independent unconventional secretory pathway. The latter trafficking may explain the rapid (<10 min) transit of a fraction of PC7 from the ER to the cell surface. Electron microscopy further confirmed the localization of PC7 to the cell surface of HEK293 cells. Within the cytosolic tail, only two cysteines (Cys(699) and Cys(704)) are palmitoylated, but this modification does not affect the choice of trafficking pathway. Swapping the transmembrane-cytosolic tail (TMCT) sequences of the convertases Furin and PC7 revealed that PC7(TMCT-Furin) is much more sulfated and hence traffics more efficiently through the conventional secretory pathway. In contrast, the Furin(TMCT-PC7) is no longer sulfated and thus reaches the cell surface by the unconventional pathway. Because trafficking of PC7(CT-Furin) and Furin(CT-PC7) resemble their wild type counterparts, we deduce that the transmembrane domain of PC7 regulates the sorting of PC7 toward the unconventional secretory pathway. In conclusion, PC7 is distinct from other proprotein convertases in its zymogen activation, subcellular localization, and trafficking.
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Affiliation(s)
- Estelle Rousselet
- From the Laboratory of Biochemical Neuroendocrinology, Clinical Research Institute of Montreal, Montreal, Quebec H2W 1R7, Canada
| | - Suzanne Benjannet
- From the Laboratory of Biochemical Neuroendocrinology, Clinical Research Institute of Montreal, Montreal, Quebec H2W 1R7, Canada
| | - Josée Hamelin
- From the Laboratory of Biochemical Neuroendocrinology, Clinical Research Institute of Montreal, Montreal, Quebec H2W 1R7, Canada
| | - Maryssa Canuel
- From the Laboratory of Biochemical Neuroendocrinology, Clinical Research Institute of Montreal, Montreal, Quebec H2W 1R7, Canada
| | - Nabil G. Seidah
- From the Laboratory of Biochemical Neuroendocrinology, Clinical Research Institute of Montreal, Montreal, Quebec H2W 1R7, Canada
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Rousselet E, Benjannet S, Marcinkiewicz E, Asselin MC, Lazure C, Seidah NG. Proprotein convertase PC7 enhances the activation of the EGF receptor pathway through processing of the EGF precursor. J Biol Chem 2011; 286:9185-95. [PMID: 21209099 DOI: 10.1074/jbc.m110.189936] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Although the processing profile of the membrane-bound epidermal growth factor precursor (pro-EGF) is tissue-specific, it has not been investigated at the cellular level nor have the cognate proteinases been defined. Among the proprotein convertases (PCs), only the membrane-bound PC7, the most ancient and conserved basic amino acid-specific PC family member, induces the processing of pro-EGF into an ∼115-kDa transmembrane form (EGF-115) at an unusual VHPR(290)↓A motif. Because site-directed mutagenesis revealed that Arg(290) is not critical, the generation of EGF-115 by PC7 is likely indirect. This was confirmed by testing a wide range of protease inhibitors, which revealed that the production of EGF-115 is most probably achieved via the activation by PC7 of a latent serine and/or cysteine protease(s). EGF-115 is more abundant at the cell surface than pro-EGF and is associated with a stronger EGF receptor (EGFR) activation, as evidenced by higher levels of phosphorylated ERK1/2. This suggests that the generation of EGF-115 represents a regulatory mechanism of juxtacrine EGFR activation. Thus, PC7 is distinct from the other PCs in its ability to enhance the activation of the cell surface EGFR.
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Affiliation(s)
- Estelle Rousselet
- Laboratory of Biochemical Neuroendocrinology, Clinical Research Institute of Montreal, Montreal, Quebec H2W 1R7, Canada
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Portela-Gomes GM, Grimelius L, Wilander E, Stridsberg M. Granins and granin-related peptides in neuroendocrine tumours. ACTA ACUST UNITED AC 2010; 165:12-20. [PMID: 20211659 DOI: 10.1016/j.regpep.2010.02.011] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2009] [Revised: 02/06/2010] [Accepted: 02/25/2010] [Indexed: 10/19/2022]
Abstract
This review focus on neuroendocrine tumours (NETs), with special reference to the immunohistochemical analysis of granins and granin-related peptides and their usefulness in identifying and characterizing the great diversity of NET types. Granins, their derived peptides, and complex protein-processing enzyme systems that cleave granins and prohormones, have to some extent cell-specific expression patterns in normal and neoplastic NE cells. The marker most commonly used in routine histopathology to differentiate between non-NETs and NETs is chromogranin (Cg) A, to some extent CgB. Other members of the granin family may also be of diagnostic value by identifying special NET types, e.g. secretogranin (Sg) VI was only found in pancreatic NETs and phaeochromocytomas. SgIII has recently arisen as an important NET marker; it was strongly expressed in NETs, with some exceptions--phaeochromocytomas expressed few cells and parathyroid adenomas none. Some expression patterns of granin-related peptides seem valuable in differentiating between some benign and malignant NETs, some may also provide prognostic information, among which: well-differentiated NET types expressed more CgA epitopes than the poorly differentiated ones, except insulinomas, where the opposite was noted; medullary thyroid carcinomas containing few cells immunoreactive to a CgB antibody were related to a bad prognosis; C-terminal secretoneurin visualized a cell type related to malignancy in phaeochromocytomas. Further research will probably establish new staining patterns with marker functions for granins in NETs which may be of histopathological diagnostic value.
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Basak A, Khatib AM, Mohottalage D, Basak S, Kolajova M, Bag SS, Basak A. A novel enediynyl peptide inhibitor of furin that blocks processing of proPDGF-A, B and proVEGF-C. PLoS One 2009; 4:e7700. [PMID: 19956642 PMCID: PMC2778948 DOI: 10.1371/journal.pone.0007700] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2009] [Accepted: 09/28/2009] [Indexed: 12/22/2022] Open
Abstract
Background Furin represents a crucial member of secretory mammalian subtilase, the Proprotein Convertase (PC) or Proprotein Convertase Subtilisin/Kexin (PCSK) superfamily. It has been linked to cancer, tumorgenesis, viral and bacterial pathogenesis. As a result it is considered a major target for intervention of these diseases. Methodology/Principal Findings Herein, we report, for the first time, the synthesis and biological evaluation of a newly designed potent furin inhibitor that contains a highly reactive beta-turn inducing and radical generating “enediynyl amino acid” (Eda) moiety. “Eda” was inserted between P1 and P1′ residues of hfurin98–112 peptide, derived from the primary cleavage site of furin's own prodomain. The resulting hexadecapeptide derivative inhibited furin in vitro with IC50 ∼40 nM when measured against the fluorogenic substrate Boc-RVRR-MCA. It also inhibited furin-mediated cleavage of a fluorogenic peptide derived from hSARS-CoV spike protein with IC50 ∼193 nM. Additionally it also blocked furin-processing of growth factors proPDGF-A, B and VEGF-C that are linked to tumor genesis and cancer. Circular dichroism study showed that this inhibitor displayed a predominantly beta-turn structure while western blots confirmed its ability to protect furin protein from self degradation. Conclusion/Significance These findings imply its potential as a therapeutic agent for intervention of cancer and other furin-associated diseases.
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Affiliation(s)
- Ajoy Basak
- Department of Biochemistry, Chronic Diseases Program, Regional Protein Chemistry Center, Ottawa Hospital Research Institute, University of Ottowa, Ottawa, Canada.
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Secreted cysteine-rich FGF receptor derives from posttranslational processing by furin-like prohormone convertases. Biochem Biophys Res Commun 2009; 382:359-64. [DOI: 10.1016/j.bbrc.2009.03.026] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2009] [Accepted: 03/05/2009] [Indexed: 11/18/2022]
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Recombinant proprotein convertase 4 (PC4) from Leishmania tarentolae expression system: Purification, biochemical study and inhibitor design. Protein Expr Purif 2008; 60:117-26. [DOI: 10.1016/j.pep.2008.03.013] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2007] [Revised: 03/12/2008] [Accepted: 03/19/2008] [Indexed: 11/18/2022]
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45
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Golabek AA, Dolzhanskaya N, Walus M, Wisniewski KE, Kida E. Prosegment of tripeptidyl peptidase I is a potent, slow-binding inhibitor of its cognate enzyme. J Biol Chem 2008; 283:16497-504. [PMID: 18411270 DOI: 10.1074/jbc.m800458200] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Tripeptidyl peptidase I (TPP I) is the first mammalian representative of a family of pepstatin-insensitive serine-carboxyl proteases, or sedolisins. The enzyme acts in lysosomes, where it sequentially removes tripeptides from the unmodified N terminus of small, unstructured polypeptides. Naturally occurring mutations in TPP I underlie a neurodegenerative disorder of childhood, classic late infantile neuronal ceroid lipofuscinosis (CLN2). Generation of mature TPP I is associated with removal of a long prosegment of 176 amino acid residues from the zymogen. Here we investigated the inhibitory properties of TPP I prosegment expressed and isolated from Escherichia coli toward its cognate protease. We show that the TPP I prosegment is a potent, slow-binding inhibitor of its parent enzyme, with an overall inhibition constant in the low nanomolar range. We also demonstrate the protective effect of the prosegment on alkaline pH-induced inactivation of the enzyme. Interestingly, the inhibitory properties of TPP I prosegment with the introduced classic late infantile neuronal ceroid lipofuscinosis disease-associated mutation, G77R, significantly differed from those revealed by wild-type prosegment in both the mechanism of interaction and the inhibitory rate. This is the first characterization of the inhibitory action of the sedolisin prosegment.
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Affiliation(s)
- Adam A Golabek
- Department of Developmental Neurobiology, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York 10314, USA.
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Mayer G, Hamelin J, Asselin MC, Pasquato A, Marcinkiewicz E, Tang M, Tabibzadeh S, Seidah NG. The regulated cell surface zymogen activation of the proprotein convertase PC5A directs the processing of its secretory substrates. J Biol Chem 2007; 283:2373-84. [PMID: 18039650 DOI: 10.1074/jbc.m708763200] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The proprotein convertases are synthesized as zymogens that acquire activity upon autocatalytic removal of their NH(2)-terminal prosegment. Based on the convertase furin, to fold properly and gain activity, the convertases PC5A, PACE4, and PC7 are presumed to undergo two sequential prosegment cleavages in the endoplasmic reticulum and then in the trans-Golgi network. However, biochemical and immunocytochemical experiments revealed that mouse PC5A is complexed to its prosegment at the plasma membrane. This labeling is lost upon treatment with heparin and is increased by overexpressing members of the syndecan family and CD44, suggesting attachment of secreted PC5A-prosegment complex to heparan sulfate proteoglycans. Following stimulation of Y1 cells with adrenocorticotropic hormone or 8-bromo-cyclic AMP, the cell surface labeling of the prosegment of PC5A is greatly diminished, whereas the signal for mature PC5A is increased. Moreover, after stimulation, the protease activity of PC5A is enhanced, as evidenced by the cleavage of the PC5A substrates Lefty, ADAMTS-4, endothelial lipase, and PCSK9. Our data suggest a novel mechanism for PC5A activation and substrate cleavage at the cell surface, through a regulated removal of its prosegment. A similar mechanism may also apply to the convertase PACE4, thereby extending our knowledge of the molecular details of the zymogen activation and functions of these heparan sulfate proteoglycan-bound convertases.
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Affiliation(s)
- Gaétan Mayer
- Laboratory of Biochemical Neuroendocrinology, Clinical Research Institute of Montreal, Montréal, Quebec H2W 1R7, Canada
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Bontemps Y, Scamuffa N, Calvo F, Khatib A. Potential opportunity in the development of new therapeutic agents based on endogenous and exogenous inhibitors of the proprotein convertases. Med Res Rev 2007; 27:631-48. [PMID: 17019676 PMCID: PMC7168524 DOI: 10.1002/med.20072] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The proprotein convertases (PCs) are responsible for the endoproteolytic processing of various protein precursors (e.g., growth factors, receptors, adhesion molecules, and matrix metalloproteinases) implicated in several diseases such as obesity, diabetes, atherosclerosis, cancer, and Alzheimer disease. The potential clinical and pharmacological role of the PCs has fostered the development of various PC‐inhibitors. In this review we summarized the recent findings on PCs inhibitors, their mode of actions and potential use in the therapy of various diseases. © 2006 Wiley Periodicals, Inc. Med Res Rev, 27, No. 5, 631–648, 2007
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Affiliation(s)
- Yannick Bontemps
- INSERM, U 716, Equipe AVENIR, Institut de Génétique Moléculaire, Paris 75010, France
- Université Paris 7, Paris 75251, France
| | - Nathalie Scamuffa
- INSERM, U 716, Equipe AVENIR, Institut de Génétique Moléculaire, Paris 75010, France
- Université Paris 7, Paris 75251, France
| | - Fabien Calvo
- INSERM, U 716, Equipe AVENIR, Institut de Génétique Moléculaire, Paris 75010, France
- Université Paris 7, Paris 75251, France
| | - Abdel‐Majid Khatib
- INSERM, U 716, Equipe AVENIR, Institut de Génétique Moléculaire, Paris 75010, France
- Université Paris 7, Paris 75251, France
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48
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De Windt A, Rai M, Bernier L, Thelen K, Soini J, Lefebvre C, Chintawar S, Lavigne J, Saarinen L, Kytömäki L, Munzer JS, Lütjohann D, Pandolfo M, Davignon J, Seidah NG, Laaksonen R. Gene Set Enrichment Analysis Reveals Several Globally Affected Pathways due to SKI-1/S1P Inhibition in HepG2 Cells. DNA Cell Biol 2007; 26:765-72. [PMID: 17867930 DOI: 10.1089/dna.2007.0624] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Sterol regulatory element-binding proteins (SREBPs) are transcription factors governing transcription of genes related to cholesterol and fatty acid metabolism. To become active, SREBPs must undergo a proteolytic cleavage to allow an active NH(2)-terminal segment to translocate into the nucleus. SKI-1/S1P is the first protease in the proteolytic activation cascade of SREBPs. SREBP inhibition may be useful, for example, in the treatment of liver steatosis caused by homocysteine-induced lipid synthesis. Accordingly, we overexpressed inhibitory prodomains (proSKI) of SKI-1/S1P in HepG2 cells to block SREBP activation to evaluate the potential of SKI-1/S1P in controlling cellular cholesterol synthesis. SKI-1/S1P inhibition resulted in reduced cholesterol synthesis and mRNA levels of the rate-limiting enzymes, HMG-CoA reductase and squalene epoxidase, in the cholesterol synthetic pathway. The inhibitory effect was maintained in the presence of homocysteine-induced endoplasmic reticulum stress. A gene set enrichment analysis was performed to elucidate other metabolic effects caused by SKI-1/S1P inhibition. SKI-1/S1P inhibition was observed to affect a number of other metabolic pathways, including glycolysis and citric acid cycle. These results demonstrate that inhibition of SREBPs decreases cholesterol synthesis in HepG2 cells both in the absence and presence of homocysteine. SKI-1/S1P inhibition may cause widespread changes in other key metabolic pathways.
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Affiliation(s)
- Aloys De Windt
- Department of Neurology, Free University of Brussels, Brussels, Belgium
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Basak A, Mitra A, Basak S, Pasko C, Chrétien M, Seaton P. A fluorogenic peptide containing the processing site of human SARS corona virus S-protein: kinetic evaluation and NMR structure elucidation. Chembiochem 2007; 8:1029-37. [PMID: 17471479 PMCID: PMC7162000 DOI: 10.1002/cbic.200700007] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Human severe acute respiratory syndrome coronavirus (hSARS‐CoV) is the causative agent for SARS infection. Its surface glycoprotein (spike protein) is considered to be one of the prime targets for SARS therapeutics and intervention because its proteolytic maturation by a host protease is crucial for host–virus fusion. Using intramolecularly quenched fluorogenic (IQF) peptides based on hSARS‐CoV spike protein (Abz‐755Glu‐Gln‐Asp‐Arg‐Asn‐Thr‐Arg‐Glu‐Val‐Phe‐Ala‐Gln766‐Tyx‐NH2) and in vitro studies, we show that besides furin, other PCs, like PC5 and PC7, might also be involved in this cleavage event. Through kinetic measurements with recombinant PCs, we observed that the peptide was cleaved efficiently by both furin and PC5, but very poorly by PC7. The cleavage could be blocked by a PC‐inhibitor, α1‐PDX, in a dose‐dependent manner. Circular dichroism spectra indicated that this peptide possesses a high degree of sheet structure. Following cleavage by furin, the sheet content increased, possibly at the expense of turn and random structures. 1H NMR spectra from 2D COSY and ROESY experiments under physiological buffer and pH conditions indicated that this peptide possesses a structure with a turn at its C‐terminal segment, close to the cleavage site. The data suggest that the cleavable peptide bond is located within the most exposed domain; this is supported by the nearby turn structure. Several strong to weak NMR ROESY correlations were detected, and a 3D structure of the spike IQF peptide that contains the crucial cleavage site R761↓E has been proposed.
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Affiliation(s)
- Ajoy Basak
- Hormone, Growth, and Development Program, Regional Protein Chemistry Center, Ottawa Health Research Institute, University of Ottawa, 725 Parkdale Ave., Ottawa, ON K1Y 4E9, Canada
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Lapierre M, Siegfried G, Scamuffa N, Bontemps Y, Calvo F, Seidah NG, Khatib AM. Opposing Function of the Proprotein Convertases Furin and PACE4 on Breast Cancer Cells' Malignant Phenotypes: Role of Tissue Inhibitors of Metalloproteinase-1. Cancer Res 2007; 67:9030-4. [PMID: 17909005 DOI: 10.1158/0008-5472.can-07-0807] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Proteolytic cleavage of various cancer-related substrates by the proprotein convertases (PC) was reported to be important in the processes of neoplasia. These enzymes are inhibited by their naturally occurring inhibitors, the prosegments (ppPC), and by the engineered general PC inhibitor, the serpin variant alpha1-PDX. In the present study, we sought to compare the effect of these PC inhibitors on malignant phenotypes of breast cancer cells. Overexpression in a stable manner of alpha1-PDX and the prosegment ppPACE4 in MDA-MB-231 breast cancer cells resulted in increased matrix metalloproteinase (MMP)-9 (but not MMP-2) activity and a reduced secretion of tissue inhibitor of metalloproteinase 1 (TIMP-1). This was associated with significant enhancement in cell motility, migration, and invasion of collagen in vitro. In contrast, ppFurin expression in these cells decreased MMP-9 activity and diminished these biological functions, but had no significant effect on TIMP-1 secretion. Taken together, these data showed the specific and opposing roles of Furin and PACE4 in the regulation of MMP-9/TIMP-1-mediated cell motility and invasion.
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Affiliation(s)
- Marion Lapierre
- INSERM U716, Team AVENIR, Institut de Génétique Moléculaire, Université Paris 7, Paris, France
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