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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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2
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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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3
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Pickett LA, Yourshaw M, Albornoz V, Chen Z, Solorzano-Vargas RS, Nelson SF, Martín MG, Lindberg I. Functional consequences of a novel variant of PCSK1. PLoS One 2013; 8:e55065. [PMID: 23383060 PMCID: PMC3557230 DOI: 10.1371/journal.pone.0055065] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2012] [Accepted: 12/22/2012] [Indexed: 12/02/2022] Open
Abstract
BACKGROUND Common single nucleotide polymorphisms (SNPs) in proprotein convertase subtilisin/kexin type 1 with modest effects on PC1/3 in vitro have been associated with obesity in five genome-wide association studies and with diabetes in one genome-wide association study. We here present a novel SNP and compare its biosynthesis, secretion and catalytic activity to wild-type enzyme and to SNPs that have been linked to obesity. METHODOLOGY/PRINCIPAL FINDINGS A novel PC1/3 variant introducing an Arg to Gln amino acid substitution at residue 80 (within the secondary cleavage site of the prodomain) (rs1799904) was studied. This novel variant was selected for analysis from the 1000 Genomes sequencing project based on its predicted deleterious effect on enzyme function and its comparatively more frequent allele frequency. The actual existence of the R80Q (rs1799904) variant was verified by Sanger sequencing. The effects of this novel variant on the biosynthesis, secretion, and catalytic activity were determined; the previously-described obesity risk SNPs N221D (rs6232), Q665E/S690T (rs6234/rs6235), and the Q665E and S690T SNPs (analyzed separately) were included for comparative purposes. The novel R80Q (rs1799904) variant described in this study resulted in significantly detrimental effects on both the maturation and in vitro catalytic activity of PC1/3. CONCLUSION/SIGNIFICANCE Our findings that this novel R80Q (rs1799904) variant both exhibits adverse effects on PC1/3 activity and is prevalent in the population suggests that further biochemical and genetic analysis to assess its contribution to the risk of metabolic disease within the general population is warranted.
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Affiliation(s)
- Lindsay A. Pickett
- Department of Anatomy and Neurobiology, University of Maryland-Baltimore, Baltimore, Maryland, United States of America
| | - Michael Yourshaw
- Department of Human Genetics, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | - Valeria Albornoz
- Department of Anatomy and Neurobiology, University of Maryland-Baltimore, Baltimore, Maryland, United States of America
| | - Zijun Chen
- Division of Gastroenterology and Nutrition, Department of Pediatrics, Mattel Children's Hospital and David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | - R. Sergio Solorzano-Vargas
- Division of Gastroenterology and Nutrition, Department of Pediatrics, Mattel Children's Hospital and David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | - Stanley F. Nelson
- Department of Human Genetics, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles California, United States of America
| | - Martín G. Martín
- Division of Gastroenterology and Nutrition, Department of Pediatrics, Mattel Children's Hospital and David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | - Iris Lindberg
- Department of Anatomy and Neurobiology, University of Maryland-Baltimore, Baltimore, Maryland, United States of America
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4
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Gawlik K, Shiryaev SA, Zhu W, Motamedchaboki K, Desjardins R, Day R, Remacle AG, Stec B, Strongin AY. Autocatalytic activation of the furin zymogen requires removal of the emerging enzyme's N-terminus from the active site. PLoS One 2009; 4:e5031. [PMID: 19352504 PMCID: PMC2662429 DOI: 10.1371/journal.pone.0005031] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2009] [Accepted: 03/06/2009] [Indexed: 11/18/2022] Open
Abstract
Background Before furin can act on protein substrates, it must go through an ordered process of activation. Similar to many other proteinases, furin is synthesized as a zymogen (profurin) which becomes active only after the autocatalytic removal of its auto-inhibitory prodomain. We hypothesized that to activate profurin its prodomain had to be removed and, in addition, the emerging enzyme's N-terminus had to be ejected from the catalytic cleft. Methodology/Principal Findings We constructed and analyzed the profurin mutants in which the egress of the emerging enzyme's N-terminus from the catalytic cleft was restricted. Mutants were autocatalytically processed at only the primary cleavage site Arg-Thr-Lys-Arg107↓Asp108, but not at both the primary and the secondary (Arg-Gly-Val-Thr-Lys-Arg75↓Ser76) cleavage sites, yielding, as a result, the full-length prodomain and mature furins commencing from the N-terminal Asp108. These correctly processed furin mutants, however, remained self-inhibited by the constrained N-terminal sequence which continuously occupied the S′ sub-sites of the catalytic cleft and interfered with the functional activity. Further, using the in vitro cleavage of the purified prodomain and the analyses of colon carcinoma LoVo cells with the reconstituted expression of the wild-type and mutant furins, we demonstrated that a three-step autocatalytic processing including the cleavage of the prodomain at the previously unidentified Arg-Leu-Gln-Arg89↓Glu90 site, is required for the efficient activation of furin. Conclusions/Significance Collectively, our results show the restrictive role of the enzyme's N-terminal region in the autocatalytic activation mechanisms. In a conceptual form, our data apply not only to profurin alone but also to a range of self-activated proteinases.
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Affiliation(s)
- Katarzyna Gawlik
- Burnham Institute for Medical Research, La Jolla, California, United States of America
| | - Sergey A. Shiryaev
- Burnham Institute for Medical Research, La Jolla, California, United States of America
| | - Wenhong Zhu
- Burnham Institute for Medical Research, La Jolla, California, United States of America
| | | | | | - Robert Day
- University of Sherbrooke, Sherbrooke, Quebec, Canada
| | - Albert G. Remacle
- Burnham Institute for Medical Research, La Jolla, California, United States of America
| | - Boguslaw Stec
- Burnham Institute for Medical Research, La Jolla, California, United States of America
| | - Alex Y. Strongin
- Burnham Institute for Medical Research, La Jolla, California, United States of America
- * E-mail:
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Longpré JM, McCulloch DR, Koo BH, Alexander JP, Apte SS, Leduc R. Characterization of proADAMTS5 processing by proprotein convertases. Int J Biochem Cell Biol 2008; 41:1116-26. [PMID: 18992360 DOI: 10.1016/j.biocel.2008.10.008] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2008] [Revised: 09/23/2008] [Accepted: 10/10/2008] [Indexed: 11/16/2022]
Abstract
ADAMTS5 (aggrecanase-2), a key metalloprotease mediating cartilage destruction in arthritis, is synthesized as a zymogen, proADAMTS5. We report a detailed characterization of the propeptide excision mechanism and demonstrate that it is a major regulatory step with unusual characteristics. Using furin-deficient cells and a furin inhibitor, we found that proADAMTS5 was processed by proprotein convertases, specifically furin and PC7, but not PC6B. Mutagenesis of three sites containing basic residues within the ADAMTS5 propeptide (RRR(46), RRR(69) and RRRRR(261)) suggested that proADAMTS5 processing occurs after Arg(261). That furin processing was essential for ADAMTS5 activity was illustrated using the known ADAMTS5 substrate aggrecan, as well as a new substrate, versican, an important regulatory proteoglycan during mammalian development. When compared to other ADAMTS proteases, proADAMTS5 processing has several distinct features. In contrast to ADAMTS1, whose furin processing products were clearly present intracellularly, cleaved ADAMTS5 propeptide and mature ADAMTS5 were found exclusively in the conditioned medium. Despite attempts to enhance detection of intracellular proADAMTS5 processing, such as by immunoprecipitation of total ADAMTS5, overexpression of furin, and secretion blockade by monensin, neither processed ADAMTS5 propeptide nor the mature enzyme were found intracellularly, which was strongly suggestive of extracellular processing. Extracellular ADAMTS5 processing was further supported by activation of proADAMTS5 added exogenously to HEK293 cells stably expressing furin. Unlike proADAMTS9, which is processed by furin at the cell-surface, to which it is bound, ADAMTS5 does not bind the cell-surface. Thus, the propeptide processing mechanism of ADAMTS5 has several points of distinction from those of other ADAMTS proteases, which may have considerable significance in the context of osteoarthritis.
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Affiliation(s)
- Jean-Michel Longpré
- Department of Pharmacology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Que. J1H 5N4, Canada
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6
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Wang S, Han J, Wang Y, Lu W, Chi C. Design of peptide inhibitors for furin based on the C-terminal fragment of histone H1.2. Acta Biochim Biophys Sin (Shanghai) 2008. [PMID: 18850049 PMCID: PMC7110110 DOI: 10.1111/j.1745-7270.2008.00470.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
The mammalian proprotein convertase furin has been found to play an important role in diverse physiological and pathological events, such as the activation of viral glycoproteins and bacterial exotoxins. Small, non‐toxic and highly active, furin inhibitors are considered to be attractive drug candidates for diseases caused by virus and bacteria. In this study, a series of peptide inhibitors were designed and synthesized based on the C‐terminal fragment of histone H1.2, which has an inhibitory effect on furin. Replacing the reactive site of inhibitors with the consensus substrate recognition sequence of furin has been found to increase inhibitory activity greatly. The most potent inhibitor, I4, with 14 amino acid residues has a Ki value of 17 nM for furin. Although most of the synthesized peptides were temporary inhibitors, the inhibitor I5, with nine amino acids, retained its full potency, even after a 3 h incubation period with furin at 37 °C. These inhibitors may potentially lead to the development of anti‐viral and antibacterial drug compounds.
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Affiliation(s)
- Suming Wang
- School of Life Sciences, University of Science and Technology of China, Anhui 230027, China
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7
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Bhattacharjya S, Xu P, Wang P, Osborne MJ, Ni F. Conformational analyses of a partially-folded bioactive prodomain of human furin. Biopolymers 2007; 86:329-44. [PMID: 17477394 DOI: 10.1002/bip.20748] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The 81-residue multifunctional prodomain of human furin adopts only a partially-folded conformational state under near physiological conditions. By use of NMR spectroscopy, we demonstrate that the N-terminal residues 1-46 of the prodomain in 50% trifluoroethanol (TFE) populates backbone conformations containing a short helix, a beta-strand and a helix-loop-helix super-secondary structure with elements of tertiary interactions. (15)N NMR relaxation measurements indicate that the helix-loop-helix region has similar motional characteristics in the fast picosecond to nanosecond timescales. On the other hand, the intervening segment (residues 47-65) is predominantly unstructured with a long and highly flexible region surrounding the protease 'activation loop' followed by a partially helical segment in the C-terminal end. Interestingly, the helix-loop-helix "fold" was found to be populated even when excised out of the full-length prodomain, since a peptide fragment derived from residues Pro16-Arg49 can also form the helix-loop-helix structure in aqueous solution in the absence of TFE. Structure analyses reveal that two helices orient in an antiparallel fashion directed by the sharing of hydrophobic residues involved in helix-capping interactions. Very importantly, a positively-charged Lys residue replacing His43 in the 16-49 fragment imparts stability to the super-secondary structure at both acidic and neutral pH, while a hydrophobic residue Leu at position 43 appears to destabilize the helical conformation in the 31-44 region. As such, this study provides valuable insights into the structural properties of the furin prodomain in relation to its role in the folding of the furin zymogen and its inhibitory action toward furin.
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Affiliation(s)
- Surajit Bhattacharjya
- Biomolecular NMR and Protein Research Laboratory, Biotechnology Research Institute, National Research Council of Canada, 6100 Royalmount Avenue, Montreal, Quebec, Canada
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8
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Han J, Zhang L, Shao X, Shi J, Chi C. The potent inhibitory activity of histone H1.2 C-terminal fragments on furin. FEBS J 2006; 273:4459-69. [PMID: 16956366 DOI: 10.1111/j.1742-4658.2006.05451.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Many physiologically important proproteins, pathogenic bacterial exotoxins and viral envelope glycoproteins are activated by the proprotein convertase furin, which makes furin inhibitor a hot target for basic research and drug design. Although synthetic and bioengineered inhibitors of furin have been well characterized, its endogenous inhibitor has not been directly purified from mammalian tissues to date. In this study, three inhibitors were purified from the porcine liver by using a combination of chromatographic techniques, and identified to be the C-terminal truncated fragments with different sizes of histone H1.2. The gene of porcine histone H1.2 was cloned and sequenced, further confirming the determined sequences. These three C-terminal fragments inhibited furin with Ki values around 2 x 10(-7) m while the full-length histone H1.2 inhibited it with a lesser activity, suggesting that the inhibitory activity relies on the C-terminal lysine-rich domain. Though the inhibition was temporary, these inhibitors were specific, and the reactive site of one C-terminal fragment was identified. A 36 amino acid peptide around the reactive site was synthesized, which could still inhibit furin with a Ki of 5.2 x 10(-7) m.
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Affiliation(s)
- Jinbo Han
- Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Graduate School of the Chinese Academy of Sciences, Shanghai, China
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9
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Feliciangeli SF, Thomas L, Scott GK, Subbian E, Hung CH, Molloy SS, Jean F, Shinde U, Thomas G. Identification of a pH sensor in the furin propeptide that regulates enzyme activation. J Biol Chem 2006; 281:16108-16. [PMID: 16601116 PMCID: PMC4293020 DOI: 10.1074/jbc.m600760200] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The folding and activation of furin occur through two pH- and compartment-specific autoproteolytic steps. In the endoplasmic reticulum (ER), profurin folds under the guidance of its prodomain and undergoes an autoproteolytic excision at the consensus furin site Arg-Thr-Lys-Arg107/ generating an enzymatically masked furin-propeptide complex competent for transport to late secretory compartments. In the mildly acidic environment of the trans-Golgi network/endosomal system, the bound propeptide is cleaved at the internal site 69HRGVTKR75/, unmasking active furin capable of cleaving substrates in trans. Here, by using cellular, biochemical, and modeling studies, we demonstrate that the conserved His69 is a pH sensor that regulates the compartment-specific cleavages of the propeptide. In the ER, unprotonated His69 stabilizes a solvent-accessible hydrophobic pocket necessary for autoproteolytic excision at Arg107. Profurin molecules unable to form the hydrophobic pocket, and hence, the furin-propeptide complex, are restricted to the ER by a PACS-2- and COPI-dependent mechanism. Once exposed to the acidic pH of the late secretory pathway, protonated His69 disrupts the hydrophobic pocket, resulting in exposure and cleavage of the internal cleavage site at Arg75 to unmask the enzyme. Together, our data explain the pH-regulated activation of furin and how this His-dependent regulatory mechanism is a model for other proteins.
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Affiliation(s)
| | - Laurel Thomas
- Vollum Institute, Oregon Health and Science University, Portland, Oregon 97239
| | - Gregory K. Scott
- Vollum Institute, Oregon Health and Science University, Portland, Oregon 97239
| | - Ezhilkani Subbian
- Department of Biochemistry and Molecular Biology, Oregon Health and Science University, Portland, Oregon 97239
| | - Chien-Hui Hung
- Vollum Institute, Oregon Health and Science University, Portland, Oregon 97239
| | - Sean S. Molloy
- Vollum Institute, Oregon Health and Science University, Portland, Oregon 97239
| | - François Jean
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Ujwal Shinde
- Department of Biochemistry and Molecular Biology, Oregon Health and Science University, Portland, Oregon 97239
| | - Gary Thomas
- Vollum Institute, Oregon Health and Science University, Portland, Oregon 97239
- To whom correspondence should be addressed: Vollum Institute, Oregon Health and Science University, 3181 SW Sam Jackson Park Rd., Portland, OR 97239. Tel.: 503-494-6955; Fax: 503-494-1218;
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10
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Rabah N, Gauthier D, Wilkes BC, Gauthier DJ, Lazure C. Single amino acid substitution in the PC1/3 propeptide can induce significant modifications of its inhibitory profile toward its cognate enzyme. J Biol Chem 2006; 281:7556-67. [PMID: 16407210 DOI: 10.1074/jbc.m510607200] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The proprotein convertase PC1/3 is synthesized as a large precursor that undergoes proteolytic processing of the signal peptide, the propeptide and ultimately the COOH-terminal tail, to generate the mature form. The propeptide is essential for protease folding, and, although cleaved by an autocatalytic process, it remains associated with the mature form acting as an auto-inhibitor of PC1/3. To further assess the role of certain residues in its interaction with its cognate enzyme, we performed an alanine scan on two PC1/3 propeptide potential cleavable sites ((50)RRSRR(54) and (61)KR(62)) and an acidic region (65)DDD(67) conserved among species. Upon incubation with PC1/3, the ensuing peptides exhibit equal inhibitory potency, lower potency, or higher potency than the wild-type propeptide. The K(i) values calculated varied between 0.15 and 16.5 nm. All but one mutant exhibited a tight binding behavior. To examine the specificity of mutants, we studied their reactivity toward furin, a closely related convertase. The mutation of certain residues also affects the inhibition behavior toward furin yielding propeptides exhibiting K(i) ranging from 0.2 to 24 nm. Mutant propeptides exhibited against each enzyme either different mode of inhibition, enhanced selectivity in the order of 40-fold for one enzyme, or high potency with no discrimination. Hence, we demonstrate through single amino acid substitution that it is feasible to modify the inhibitory behavior of propeptides toward convertases in such a way as to increase or decrease their potency, modify their inhibitory mechanisms, as well as increase their selectivity.
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Affiliation(s)
- Nadia Rabah
- Neuropeptides Structure and Metabolism, Institut de Recherches Cliniques de Montréal, 110 Pine Avenue West, Montréal, Quebec H2W 1R7, Canada
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11
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Colige A, Ruggiero F, Vandenberghe I, Dubail J, Kesteloot F, Van Beeumen J, Beschin A, Brys L, Lapière CM, Nusgens B. Domains and Maturation Processes That Regulate the Activity of ADAMTS-2, a Metalloproteinase Cleaving the Aminopropeptide of Fibrillar Procollagens Types I–III and V. J Biol Chem 2005; 280:34397-408. [PMID: 16046392 DOI: 10.1074/jbc.m506458200] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Processing of fibrillar collagens is required to generate collagen monomers able to self-assemble into elongated and cylindrical collagen fibrils. ADAMTS-2 belongs to the "A disintegrin and metalloproteinase with thrombospondin type 1 motifs" (ADAMTS) family. It is responsible for most of the processing of the aminopropeptide of type I procollagen in the skin, and it also cleaves type II and type III procollagens. ADAMTS are complex secreted enzymes that are implicated in various physiological and pathological processes. Despite accumulating evidence indicating that their activity is regulated by ancillary domains, additional information is required for a better understanding of the specific function of each domain. We have generated 17 different recombinant forms of bovine ADAMTS-2 and characterized their processing, activity, and cleavage specificity. The results indicated the following: (i) activation of the ADAMTS-2 zymogen involves several cleavages, by proprotein convertases and C-terminal processing, and generates at least seven distinct processed forms; (ii) the C-terminal domain negatively regulates enzyme activity, whereas two thrombospondin type 1 repeats are enhancer regulators; (iii) the 104-kDa form displays the highest aminoprocollagen peptidase activity on procollagen type I; (iv) ADAMTS-2 processes the aminopropeptide of alpha1 type V procollagen homotrimer at the end of the variable domain; and (v) the cleaved sequence (PA) is different from the previously described sites ((P/A)Q) for ADAMTS-2, redefining its cleavage specificity. This finding and the existence of multiple processed forms of ADAMTS-2 strongly suggest that ADAMTS-2 may be involved in function(s) other than processing of fibrillar procollagen types I-III.
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Affiliation(s)
- Alain Colige
- Laboratory of Connective Tissues Biology, Center of Biomedical Integrative Genoproteomics, University of Liège, B-4000 SartTilman, Belgium
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12
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Salvas A, Benjannet S, Reudelhuber TL, Chrétien M, Seidah NG. Evidence for proprotein convertase activity in the endoplasmic reticulum/early Golgi. FEBS Lett 2005; 579:5621-5. [PMID: 16213495 DOI: 10.1016/j.febslet.2005.09.029] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2005] [Revised: 09/09/2005] [Accepted: 09/19/2005] [Indexed: 10/25/2022]
Abstract
Processing of precursor proteins by the proprotein convertases is thought to occur mainly in the trans-Golgi network or post-Golgi compartments. Such cleavage is inhibited by the prosegment of the convertases. During our studies of the use of the inhibitory prosegment of PC1, we noticed that a construct containing the prosegment fused to the C-terminal secretory granule sorting domain was cleaved in the endoplasmic reticulum (ER) at a pair of basic residues, best recognized by furin and PC7. This was further confirmed when this construct was fused at the C-terminus with a KDEL ER-retention signal. This suggests that the convertases could cleave some substrates within the ER, possibly by displacing the inhibitory prosegment associated with them.
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Affiliation(s)
- Alexandre Salvas
- Biochemical Neuroendocrinology Laboratory, Clinical Research Institute of Montreal, QC, Canada
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13
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Sun XM, Eden ER, Tosi I, Neuwirth CK, Wile D, Naoumova RP, Soutar AK. Evidence for effect of mutant PCSK9 on apolipoprotein B secretion as the cause of unusually severe dominant hypercholesterolaemia. Hum Mol Genet 2005; 14:1161-9. [PMID: 15772090 DOI: 10.1093/hmg/ddi128] [Citation(s) in RCA: 115] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Typically, autosomal dominant familial hypercholesterolaemia (FH) is caused by mutations in the low density lipoprotein (LDL) receptor or apolipoprotein B genes that result in defective clearance of plasma LDL by the liver, but a third gene (PCSK9), encoding a putative proprotein convertase, has recently been implicated. Two independent microarray studies support a role for PCSK9 in sterol metabolism and adenoviral-mediated over-expression of PCSK9 in mouse liver depletes hepatic LDL-receptor protein, but the mechanism by which dominant mutations cause human FH is unclear. We have identified the D374Y mutant of PCSK9 in three FH families of English origin; all 12 affected individuals have unusually severe hypercholesterolaemia and require more stringent treatment than typical FH patients, who are heterozygous for defects in the LDL receptor. We have stably expressed wild-type (WT) and variant PCSK9 in McArdle-7777 rat hepatoma cells and shown by confocal microscopy that all forms of PCSK9 co-localize with protein disulphide isomerase in the ER whether or not they can be autocleaved. Expression of the proposed pathogenic variants, but not of WT, S386A or F216L PCSK9, increases secretion of apolipoprotein B100-containing lipoproteins from the cells by 2-4-fold probably by reducing the degradation of nascent protein; no differences in LDL-receptor content were observed in cells expressing WT, S386A or F216L PCSK9 and only a small reduction in cells expressing the D374Y or S127R mutants. This suggests that the variants of PCSK9 found in FH influence the secretion of apoB-containing lipoproteins, providing an explanation for the marked increase in circulating LDL in heterozygous carriers.
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Affiliation(s)
- Xi-Ming Sun
- MRC Clinical Sciences Centre, Hammersmith Hospital, London, UK
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Henrich S, Lindberg I, Bode W, Than ME. Proprotein Convertase Models based on the Crystal Structures of Furin and Kexin: Explanation of their Specificity. J Mol Biol 2005; 345:211-27. [PMID: 15571716 DOI: 10.1016/j.jmb.2004.10.050] [Citation(s) in RCA: 129] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2004] [Revised: 10/14/2004] [Accepted: 10/15/2004] [Indexed: 11/17/2022]
Abstract
In eukaryotes, many secreted proteins and peptide hormones are excised from larger precursors by calcium-dependent serine proteinases, the proprotein/prohormone convertases (PCs). These PCs cleave their protein substrates very specifically following multiple basic residues. The seven mammalian PCs and their yeast orthologue kexin are multi-domain proteinases consisting of a subtilisin-related catalytic domain, a conserved P-domain and a variable, often cysteine-rich domain, which in some PCs is followed by an additional C-terminal trans-membrane domain and a short cytoplasmic domain. The recently published crystal structures of the soluble mouse furin and yeast kexin ectodomains have revealed the relative arrangement of catalytic and P domains, the exact domain fold and the detailed architecture of the substrate binding clefts. Based on these experimental structures, we now have modelled the structures of the other human/mouse PCs. According to topology and to structure-based sequence comparisons, these other PCs closely resemble furin, with PC4, PACE4 and PC5/6 being more similar, and PC1/3, PC2 and PC7 being less similar to furin. Except for PC1 and PC2, this order of similarity is valid for the catalytic as well as for the P domains, and is almost reversed using kexin as a reference molecule. A similar order results from the number and clustering of negative charges lining the non-prime subsites, explaining the gradually decreasing requirement for basic residues N-terminal to substrate cleavage sites. The preference of the different PCs for distinct substrates seems to be governed by overall charge compensation and matching of the detailed charge distribution pattern.
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Affiliation(s)
- Stefan Henrich
- Max-Planck-Institut für Biochemie, Abteilung für Strukturforschung, Am Klopferspitz 18, 82152 Martinsried, Germany
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Longpré JM, Leduc R. Identification of Prodomain Determinants Involved in ADAMTS-1 Biosynthesis. J Biol Chem 2004; 279:33237-45. [PMID: 15184385 DOI: 10.1074/jbc.m313151200] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The metalloprotease ADAMTS-1 (a disintegrin and metalloprotease with thrombospondin type I motif), similarly to other members of the ADAMTS family, is initially synthesized as a zymogen, proADAMTS-1, that undergoes proteolytic processing at the prodomain/catalytic domain junction by serine proteinases of the furin-like family of proprotein convertases. The goals of this study were to identify residues of the prodomain that play an essential role in ADAMTS-1 processing and to determine the identity of the convertase required for zymogen processing. To gain insight into the putative roles of specific prodomain residues in ADAMTS-1 biosynthesis, we performed biosynthetic labeling experiments in transiently transfected human embryonic kidney 293 cells expressing wild-type and prodomain mutants of proADAMTS-1. Cells expressing wild-type ADAMTS-1 initially produced a 110-kDa zymogen form that was later converted to an 87-kDa form, which was also detected in the media. Although convertases such as PACE4 and PC6B processed proADAMTS-1, we found that furin was the most efficient enzyme at producing the mature ADAMTS-1 87-kDa moiety. Site-directed mutagenesis of the two putative furin recognition sequences found within the ADAMTS-1 prodomain (RRNR173 and RKKR235) revealed that Arg235 was the sole processing site. Use of the Golgi disturbing agent, Brefeldin A, and monensin suggests that the cleavage of proADAMTS-1 takes place in the Golgi apparatus prior to its secretion. Conserved residues within the prodomain of other ADAMTS members hinted that they might act as maturation determinants. Replacement with alanine of selected residues Cys106, Tyr108, Gly110, Cys125, and Cys181 and residues encompassing the 137-144 sequence significantly affected the biosynthetic profile of the enzyme. Our results suggest that conserved residues other than the furin cleavage site in the prodomain of ADAMTS-1 are involved in its biosynthesis.
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Affiliation(s)
- Jean-Michel Longpré
- Department of Pharmacology, Faculty of Medicine, Université de Sherbrooke, Sherbrooke, Québec J1H 5N4, Canada
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