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Li G, Zhu W, Tian M, Liu R, Ruan Y, Liu C. Genome-Wide Identification of the SPP/SPPL Gene Family and BnaSPPL4 Regulating Male Fertility in Rapeseed ( Brassica napus L.). Int J Mol Sci 2024; 25:3936. [PMID: 38612746 PMCID: PMC11012144 DOI: 10.3390/ijms25073936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Revised: 03/23/2024] [Accepted: 03/31/2024] [Indexed: 04/14/2024] Open
Abstract
Signal peptide peptidase (SPP) and its homologs, signal peptide peptidase-like (SPPL) proteases, are members of the GxGD-type aspartyl protease family, which is widespread in plants and animals and is a class of transmembrane proteins with significant biological functions. SPP/SPPLs have been identified; however, the functions of SPP/SPPL in rapeseed (Brassica napus L.) have not been reported. In this study, 26 SPP/SPPLs were identified in rapeseed and categorized into three groups: SPP, SPPL2, and SPPL3. These members mainly contained the Peptidase_A22 and PA domains, which were distributed on 17 out of 19 chromosomes. Evolutionary analyses indicated that BnaSPP/SPPLs evolved with a large number of whole-genome duplication (WGD) events and strong purifying selection. Members are widely expressed and play a key role in the growth and development of rapeseed. The regulation of rapeseed pollen fertility by the BnaSPPL4 gene was further validated through experiments based on bioinformatics analysis, concluding that BnaSPPL4 silencing causes male sterility. Cytological observation showed that male infertility caused by loss of BnaSPPL4 gene function occurs late in the mononucleate stage due to microspore dysplasia.
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Affiliation(s)
- Guangze Li
- Yuelushan Laboratory, Hunan Agricultural University, Changsha 410128, China; (G.L.); (W.Z.); (M.T.); (R.L.); (Y.R.)
- Key Laboratory of Hunan Provincial on Crop Epigenetic Regulation and Development, Hunan Agricultural University, Changsha 410128, China
| | - Wenjun Zhu
- Yuelushan Laboratory, Hunan Agricultural University, Changsha 410128, China; (G.L.); (W.Z.); (M.T.); (R.L.); (Y.R.)
- Key Laboratory of Hunan Provincial on Crop Epigenetic Regulation and Development, Hunan Agricultural University, Changsha 410128, China
| | - Minyu Tian
- Yuelushan Laboratory, Hunan Agricultural University, Changsha 410128, China; (G.L.); (W.Z.); (M.T.); (R.L.); (Y.R.)
- Key Laboratory of Hunan Provincial on Crop Epigenetic Regulation and Development, Hunan Agricultural University, Changsha 410128, China
| | - Rong Liu
- Yuelushan Laboratory, Hunan Agricultural University, Changsha 410128, China; (G.L.); (W.Z.); (M.T.); (R.L.); (Y.R.)
- Key Laboratory of Hunan Provincial on Crop Epigenetic Regulation and Development, Hunan Agricultural University, Changsha 410128, China
| | - Ying Ruan
- Yuelushan Laboratory, Hunan Agricultural University, Changsha 410128, China; (G.L.); (W.Z.); (M.T.); (R.L.); (Y.R.)
- Key Laboratory of Hunan Provincial on Crop Epigenetic Regulation and Development, Hunan Agricultural University, Changsha 410128, China
| | - Chunlin Liu
- Yuelushan Laboratory, Hunan Agricultural University, Changsha 410128, China; (G.L.); (W.Z.); (M.T.); (R.L.); (Y.R.)
- Key Laboratory of Hunan Provincial on Crop Epigenetic Regulation and Development, Hunan Agricultural University, Changsha 410128, China
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Hodges SL, Bouza AA, Isom LL. Therapeutic Potential of Targeting Regulated Intramembrane Proteolysis Mechanisms of Voltage-Gated Ion Channel Subunits and Cell Adhesion Molecules. Pharmacol Rev 2022; 74:1028-1048. [PMID: 36113879 PMCID: PMC9553118 DOI: 10.1124/pharmrev.121.000340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 05/13/2022] [Indexed: 10/03/2023] Open
Abstract
Several integral membrane proteins undergo regulated intramembrane proteolysis (RIP), a tightly controlled process through which cells transmit information across and between intracellular compartments. RIP generates biologically active peptides by a series of proteolytic cleavage events carried out by two primary groups of enzymes: sheddases and intramembrane-cleaving proteases (iCLiPs). Following RIP, fragments of both pore-forming and non-pore-forming ion channel subunits, as well as immunoglobulin super family (IgSF) members, have been shown to translocate to the nucleus to function in transcriptional regulation. As an example, the voltage-gated sodium channel β1 subunit, which is also an IgSF-cell adhesion molecule (CAM), is a substrate for RIP. β1 RIP results in generation of a soluble intracellular domain, which can regulate gene expression in the nucleus. In this review, we discuss the proposed RIP mechanisms of voltage-gated sodium, potassium, and calcium channel subunits as well as the roles of their generated proteolytic products in the nucleus. We also discuss other RIP substrates that are cleaved by similar sheddases and iCLiPs, such as IgSF macromolecules, including CAMs, whose proteolytically generated fragments function in the nucleus. Importantly, dysfunctional RIP mechanisms are linked to human disease. Thus, we will also review how understanding RIP events and subsequent signaling processes involving ion channel subunits and IgSF proteins may lead to the discovery of novel therapeutic targets. SIGNIFICANCE STATEMENT: Several ion channel subunits and immunoglobulin superfamily molecules have been identified as substrates of regulated intramembrane proteolysis (RIP). This signal transduction mechanism, which generates polypeptide fragments that translocate to the nucleus, is an important regulator of gene transcription. RIP may impact diseases of excitability, including epilepsy, cardiac arrhythmia, and sudden death syndromes. A thorough understanding of the role of RIP in gene regulation is critical as it may reveal novel therapeutic strategies for the treatment of previously intractable diseases.
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Affiliation(s)
- Samantha L Hodges
- Departments of Pharmacology (S.L.H., A.A.B., L.L.I.), Neurology (L.L.I.), and Molecular & Integrative Physiology (L.L.I.), University of Michigan Medical School, Ann Arbor, Michigan
| | - Alexandra A Bouza
- Departments of Pharmacology (S.L.H., A.A.B., L.L.I.), Neurology (L.L.I.), and Molecular & Integrative Physiology (L.L.I.), University of Michigan Medical School, Ann Arbor, Michigan
| | - Lori L Isom
- Departments of Pharmacology (S.L.H., A.A.B., L.L.I.), Neurology (L.L.I.), and Molecular & Integrative Physiology (L.L.I.), University of Michigan Medical School, Ann Arbor, Michigan
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3
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Schwake C, Hyon M, Chishti AH. Signal peptide peptidase: A potential therapeutic target for parasitic and viral infections. Expert Opin Ther Targets 2022; 26:261-273. [PMID: 35235480 DOI: 10.1080/14728222.2022.2047932] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
INTRODUCTION Signal peptide peptidase (SPP) is a GxGD-type intramembrane-cleaving aspartyl protease responsible for clearing accumulating signal peptides in the endoplasmic reticulum. SPP is conserved among all kingdoms and is essential for maintaining cell homeostasis. Inhibition of SPP with selective inhibitors and the structurally similar HIV protease inhibitors results in signal peptide accumulation and subsequent cell death. Identification of SPP homologues in major human parasitic infections has opened a new therapeutic opportunity. Moreover, the essentiality of mammalian SPP-mediated viral protein processing during infection is emerging. AREAS COVERED This review introduces the discovery and biological function of human SPP enzymes and identify parasitic homologues as pharmacological targets of both SPP and HIV protease inhibitors. Later, the role of mammalian SPP during viral infection and how disruption of host SPP can be employed as a novel antiviral therapy are examined and discussed. EXPERT OPINION Parasitic and viral infections cause severe health and economic burden, exacerbated by the lack of new therapeutics in the pipeline. SPP has been shown to be essential for malaria parasite growth and encouraging evidence in other parasites demonstrates broad essentiality of these proteases as therapeutic targets. As drug resistant parasite and viruses emerge, SPP inhibition will provide a new generation of compounds to counter the growing threat of antimicrobial resistance.
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Affiliation(s)
- Christopher Schwake
- Department of Developmental, Molecular, and Chemical Biology, Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, MA, USA
| | - Michael Hyon
- Department of Developmental, Molecular, and Chemical Biology, Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, MA, USA
| | - Athar H Chishti
- Department of Developmental, Molecular, and Chemical Biology, Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, MA, USA
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Spitz C, Schlosser C, Guschtschin-Schmidt N, Stelzer W, Menig S, Götz A, Haug-Kröper M, Scharnagl C, Langosch D, Muhle-Goll C, Fluhrer R. Non-canonical Shedding of TNFα by SPPL2a Is Determined by the Conformational Flexibility of Its Transmembrane Helix. iScience 2020; 23:101775. [PMID: 33294784 PMCID: PMC7689174 DOI: 10.1016/j.isci.2020.101775] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 10/21/2020] [Accepted: 11/03/2020] [Indexed: 12/22/2022] Open
Abstract
Ectodomain (EC) shedding defines the proteolytic removal of a membrane protein EC and acts as an important molecular switch in signaling and other cellular processes. Using tumor necrosis factor (TNF)α as a model substrate, we identify a non-canonical shedding activity of SPPL2a, an intramembrane cleaving aspartyl protease of the GxGD type. Proline insertions in the TNFα transmembrane (TM) helix strongly increased SPPL2a non-canonical shedding, while leucine mutations decreased this cleavage. Using biophysical and structural analysis, as well as molecular dynamic simulations, we identified a flexible region in the center of the TNFα wildtype TM domain, which plays an important role in the processing of TNFα by SPPL2a. This study combines molecular biology, biochemistry, and biophysics to provide insights into the dynamic architecture of a substrate's TM helix and its impact on non-canonical shedding. Thus, these data will provide the basis to identify further physiological substrates of non-canonical shedding in the future.
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Affiliation(s)
- Charlotte Spitz
- Biochemistry and Molecular Biology, Institute of Theoretical Medicine, Medical Faculty, University of Augsburg, Universitätsstrasse 2, 86159 Augsburg, Germany
| | - Christine Schlosser
- Biochemistry and Molecular Biology, Institute of Theoretical Medicine, Medical Faculty, University of Augsburg, Universitätsstrasse 2, 86159 Augsburg, Germany
| | - Nadja Guschtschin-Schmidt
- Karlsruhe Institute of Technology, Institute for Biological Interfaces 4, 76344 Eggenstein- Leopoldshafen, Germany and Karlsruhe Institute of Technology, Institute of Organic Chemistry, 76131 Karlsruhe, Germany
| | - Walter Stelzer
- Lehrstuhl für Chemie der Biopolymere, Technische Universität München, Weihenstephaner Berg 3, 85354 Freising, Germany
| | - Simon Menig
- Physics of Synthetic Biological Systems, Technische Universität München, Maximus-von-Imhof Forum 4, 85340 Freising, Germany
| | - Alexander Götz
- Present Address: Leibniz Supercomputing Centre, Boltzmannstr. 1, 85748 Garching, Germany
| | - Martina Haug-Kröper
- Biochemistry and Molecular Biology, Institute of Theoretical Medicine, Medical Faculty, University of Augsburg, Universitätsstrasse 2, 86159 Augsburg, Germany
| | - Christina Scharnagl
- Physics of Synthetic Biological Systems, Technische Universität München, Maximus-von-Imhof Forum 4, 85340 Freising, Germany
| | - Dieter Langosch
- Lehrstuhl für Chemie der Biopolymere, Technische Universität München, Weihenstephaner Berg 3, 85354 Freising, Germany
| | - Claudia Muhle-Goll
- Karlsruhe Institute of Technology, Institute for Biological Interfaces 4, 76344 Eggenstein- Leopoldshafen, Germany and Karlsruhe Institute of Technology, Institute of Organic Chemistry, 76131 Karlsruhe, Germany
| | - Regina Fluhrer
- Biochemistry and Molecular Biology, Institute of Theoretical Medicine, Medical Faculty, University of Augsburg, Universitätsstrasse 2, 86159 Augsburg, Germany.,DZNE - German Center for Neurodegenerative Diseases, Feodor-Lynen-Str 17, 81377 Munich, Germany
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5
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Papadopoulou AA, Fluhrer R. Signaling Functions of Intramembrane Aspartyl-Proteases. Front Cardiovasc Med 2020; 7:591787. [PMID: 33381526 PMCID: PMC7768045 DOI: 10.3389/fcvm.2020.591787] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 11/16/2020] [Indexed: 01/18/2023] Open
Abstract
Intramembrane proteolysis is more than a mechanism to “clean” the membranes from proteins no longer needed. By non-reversibly modifying transmembrane proteins, intramembrane cleaving proteases hold key roles in multiple signaling pathways and often distinguish physiological from pathological conditions. Signal peptide peptidase (SPP) and signal peptide peptidase-like proteases (SPPLs) recently have been associated with multiple functions in the field of signal transduction. SPP/SPPLs together with presenilins (PSs) are the only two families of intramembrane cleaving aspartyl proteases known in mammals. PS1 or PS2 comprise the catalytic center of the γ-secretase complex, which is well-studied in the context of Alzheimer's disease. The mammalian SPP/SPPL family of intramembrane cleaving proteases consists of five members: SPP and its homologous proteins SPPL2a, SPPL2b, SPPL2c, and SPPL3. Although these proteases were discovered due to their homology to PSs, it became evident in the past two decades that no physiological functions are shared between these two families. Based on studies in cell culture models various substrates of SPP/SPPL proteases have been identified in the past years and recently-developed mouse lines lacking individual members of this protease family, will help to further clarify the physiological functions of these proteases. In this review we concentrate on signaling roles of mammalian intramembrane cleaving aspartyl proteases. In particular, we will highlight the signaling roles of PS via its substrates NOTCH, VEGF, and others, mainly focusing on its involvement in vasculature. Delineating also signaling pathways that are affected and/or controlled by SPP/SPPL proteases. From SPP's participation in tumor progression and survival, to SPPL3's regulation of protein glycosylation and SPPL2c's control over cellular calcium stores, various crossovers between proteolytic activity of intramembrane proteases and cell signaling will be described.
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Affiliation(s)
- Alkmini A Papadopoulou
- Biochemistry and Molecular Biology, Institute of Theoretical Medicine, Medical Faculty, University of Augsburg, Augsburg, Germany
| | - Regina Fluhrer
- Biochemistry and Molecular Biology, Institute of Theoretical Medicine, Medical Faculty, University of Augsburg, Augsburg, Germany.,German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
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6
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Signal Peptide Peptidase-Type Proteases: Versatile Regulators with Functions Ranging from Limited Proteolysis to Protein Degradation. J Mol Biol 2020; 432:5063-5078. [DOI: 10.1016/j.jmb.2020.05.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 05/02/2020] [Accepted: 05/19/2020] [Indexed: 12/15/2022]
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7
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Ran Y, Hossain F, Pannuti A, Lessard CB, Ladd GZ, Jung JI, Minter LM, Osborne BA, Miele L, Golde TE. γ-Secretase inhibitors in cancer clinical trials are pharmacologically and functionally distinct. EMBO Mol Med 2018; 9:950-966. [PMID: 28539479 PMCID: PMC5494507 DOI: 10.15252/emmm.201607265] [Citation(s) in RCA: 107] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
γ-Secretase inhibitors (GSIs) are being actively repurposed as cancer therapeutics based on the premise that inhibition of NOTCH1 signaling in select cancers is therapeutic. Using novel assays to probe effects of GSIs against a broader panel of substrates, we demonstrate that clinical GSIs are pharmacologically distinct. GSIs show differential profiles of inhibition of the various NOTCH substrates, with some enhancing cleavage of other NOTCH substrates at concentrations where NOTCH1 cleavage is inhibited. Several GSIs are also potent inhibitors of select signal peptide peptidase (SPP/SPPL) family members. Extending these findings to mammosphere inhibition assays in triple-negative breast cancer lines, we establish that these GSIs have different functional effects. We also demonstrate that the processive γ-secretase cleavage pattern established for amyloid precursor protein (APP) occurs in multiple substrates and that potentiation of γ-secretase cleavage is attributable to a direct action of low concentrations of GSIs on γ-secretase. Such data definitively demonstrate that the clinical GSIs are not biological equivalents, and provide an important framework to evaluate results from ongoing and completed human trials with these compounds.
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Affiliation(s)
- Yong Ran
- Department of Neuroscience, Center for Translational Research in Neurodegenerative Disease, and McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Fokhrul Hossain
- Department of Genetics and Stanley S. Scott Cancer Center, Louisiana State University Health Sciences Center, New Orleans, LA, USA
| | - Antonio Pannuti
- Department of Genetics and Stanley S. Scott Cancer Center, Louisiana State University Health Sciences Center, New Orleans, LA, USA
| | - Christian B Lessard
- Department of Neuroscience, Center for Translational Research in Neurodegenerative Disease, and McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Gabriela Z Ladd
- College of Pharmacy, University of Florida, Gainesville, FL, USA
| | - Joo In Jung
- Department of Neuroscience, Center for Translational Research in Neurodegenerative Disease, and McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Lisa M Minter
- Department of Veterinary and Animal Sciences and Program in Molecular and Cellular Biology, University of Massachusetts, Amherst, MA, USA
| | - Barbara A Osborne
- Department of Veterinary and Animal Sciences and Program in Molecular and Cellular Biology, University of Massachusetts, Amherst, MA, USA
| | - Lucio Miele
- Department of Genetics and Stanley S. Scott Cancer Center, Louisiana State University Health Sciences Center, New Orleans, LA, USA
| | - Todd E Golde
- Department of Neuroscience, Center for Translational Research in Neurodegenerative Disease, and McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, FL, USA
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8
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Schaefer B, Moriishi K, Behrends S. Insights into the mechanism of isoenzyme-specific signal peptide peptidase-mediated translocation of heme oxygenase. PLoS One 2017; 12:e0188344. [PMID: 29155886 PMCID: PMC5695791 DOI: 10.1371/journal.pone.0188344] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Accepted: 11/06/2017] [Indexed: 11/19/2022] Open
Abstract
It has recently been shown that signal peptide peptidase (SPP) can catalyze the intramembrane cleavage of heme oxygenase-1 (HO-1) that leads to translocation of HO-1 into the cytosol and nucleus. While there is consensus that translocated HO-1 promotes tumor progression and drug resistance, the physiological signals leading to SPP-mediated intramembrane cleavage of HO-1 and the specificity of the process remain unclear. In this study, we used co-immunoprecipitation and confocal laser scanning microscopy to investigate the translocation mechanism of HO-1 and its regulation by SPP. We show that HO-1 and the closely related HO-2 isoenzyme bind to SPP under normoxic conditions. Under hypoxic conditions SPP mediates intramembrane cleavage of HO-1, but not HO-2. In experiments with an inactive HO-1 mutant (H25A) we show that translocation is independent of the catalytic activity of HO-1. Studies with HO-1 / HO-2 chimeras indicate that the membrane anchor, the PEST-domain and the nuclear shuttle sequence of HO-1 are necessary for full cleavage and subsequent translocation under hypoxic conditions. In the presence of co-expressed exogenous SPP, the anchor and the PEST-domain are sufficient for translocation. Taken together, we identified the domains involved in HO-1 translocation and showed that SPP-mediated cleavage is isoform-specific and independent of HO-activity. A closer understanding of the translocation mechanism of HO-1 is of particular importance because nuclear HO-1 seems to lead to tumor progression and drug resistance.
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Affiliation(s)
- Bianca Schaefer
- Department of Pharmacology, Toxicology and Clinical Pharmacy, University of Braunschweig—Institute of Technology, Braunschweig, Germany
| | - Kohji Moriishi
- Department of Microbiology, Faculty of Medicine Yamanashi University, Yamanashi, Japan
| | - Soenke Behrends
- Department of Pharmacology, Toxicology and Clinical Pharmacy, University of Braunschweig—Institute of Technology, Braunschweig, Germany
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9
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Signal peptide peptidase and SPP-like proteases - Possible therapeutic targets? BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2017. [PMID: 28624439 DOI: 10.1016/j.bbamcr.2017.06.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Signal peptide peptidase (SPP) and the four homologous SPP-like proteases SPPL2a, SPPL2b, SPPL2c and SPPL3 are GxGD-type intramembrane-cleaving proteases (I-CLIPs). In addition to divergent subcellular localisations, distinct differences in the mechanistic properties and substrate requirements of individual family members have been unravelled. SPP/SPPL proteases employ a catalytic mechanism related to that of the γ-secretase complex. Nevertheless, differential targeting of SPP/SPPL proteases and γ-secretase by inhibitors has been demonstrated. Furthermore, also within the SPP/SPPL family significant differences in the sensitivity to currently available inhibitory compounds have been reported. Though far from complete, our knowledge on pathophysiological functions of SPP/SPPL proteases, in particular based on studies in mice, has been significantly increased over the last years. Based on this, inhibition of distinct SPP/SPPL proteases has been proposed as a novel therapeutic concept e.g. for the treatment of autoimmunity and viral or protozoal infections, as we will discuss in this review. This article is part of a Special Issue entitled: Proteolysis as a Regulatory Event in Pathophysiology edited by Stefan Rose-John.
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10
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Naing SH, Vukoti KM, Drury JE, Johnson JL, Kalyoncu S, Hill SE, Torres MP, Lieberman RL. Catalytic Properties of Intramembrane Aspartyl Protease Substrate Hydrolysis Evaluated Using a FRET Peptide Cleavage Assay. ACS Chem Biol 2015; 10:2166-74. [PMID: 26118406 DOI: 10.1021/acschembio.5b00305] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Chemical details of intramembrane proteolysis remain elusive despite its prevalence throughout biology. We developed a FRET peptide assay for the intramembrane aspartyl protease (IAP) from Methanoculleus marisnigri JR1 in combination with quantitative mass spectrometry cleavage site analysis. IAP can hydrolyze the angiotensinogen sequence, a substrate for the soluble aspartyl protease renin, at a predominant cut site, His-Thr. Turnover is slow (min(-1) × 10(-3)), affinity and Michaelis constant (Km) values are in the low micromolar range, and both catalytic rates and cleavage sites are the same in detergent as reconstituted into bicelles. Three well-established, IAP-directed inhibitors were directly confirmed as competitive, albeit with modest inhibitor constant (Ki) values. Partial deletion of the first transmembrane helix results in a biophysically similar but less active enzyme than full-length IAP, indicating a catalytic role. Our study demonstrates previously unappreciated similarities with soluble aspartyl proteases, provides new biochemical features of IAP and inhibitors, and offers tools to study other intramembrane protease family members in molecular detail.
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Affiliation(s)
- Swe-Htet Naing
- School
of Chemistry and Biochemistry, Georgia Institute of Technology, 901 Atlantic
Drive Northwest, Atlanta, Georgia 30332-0400, United States
| | - Krishna M. Vukoti
- School
of Biology, Georgia Institute of Technology, 310 Ferst Drive Northwest, Atlanta, Georgia 30332-0230, United States
| | - Jason E. Drury
- School
of Chemistry and Biochemistry, Georgia Institute of Technology, 901 Atlantic
Drive Northwest, Atlanta, Georgia 30332-0400, United States
| | - Jennifer L. Johnson
- School
of Chemistry and Biochemistry, Georgia Institute of Technology, 901 Atlantic
Drive Northwest, Atlanta, Georgia 30332-0400, United States
| | - Sibel Kalyoncu
- School
of Chemistry and Biochemistry, Georgia Institute of Technology, 901 Atlantic
Drive Northwest, Atlanta, Georgia 30332-0400, United States
| | - Shannon E. Hill
- School
of Chemistry and Biochemistry, Georgia Institute of Technology, 901 Atlantic
Drive Northwest, Atlanta, Georgia 30332-0400, United States
| | - Matthew P. Torres
- School
of Biology, Georgia Institute of Technology, 310 Ferst Drive Northwest, Atlanta, Georgia 30332-0230, United States
| | - Raquel L. Lieberman
- School
of Chemistry and Biochemistry, Georgia Institute of Technology, 901 Atlantic
Drive Northwest, Atlanta, Georgia 30332-0400, United States
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11
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Gertsik N, Chau DM, Li YM. γ-Secretase Inhibitors and Modulators Induce Distinct Conformational Changes in the Active Sites of γ-Secretase and Signal Peptide Peptidase. ACS Chem Biol 2015; 10:1925-31. [PMID: 26030233 DOI: 10.1021/acschembio.5b00321] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
γ-Secretase inhibitors (GSIs) and modulators (GSMs) are at the frontline of cancer and Alzheimer's disease research, respectively. While both are therapeutically promising, not much is known about their interactions with proteins other than γ-secretase. Signal peptide peptidase (SPP), like γ-secretase, is a multispan transmembrane aspartyl protease that catalyzes regulated intramembrane proteolysis. We used active site-directed photophore walking probes to study the effects of different GSIs and GSMs on the active sites of γ-secretase and SPP and found that nontransition state GSIs inhibit labeling of γ-secretase by activity-based probes but enhance labeling of SPP. The opposite is true of GSMs, which have little effect on the labeling of γ-secretase but diminish labeling of SPP. These results demonstrate that GSIs and GSMs are altering the structure of not only γ-secretase but also SPP, leading to potential changes in enzyme activity and specificity that may impact the clinical outcomes of these molecules.
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Affiliation(s)
- Natalya Gertsik
- Molecular
Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, New York 10065, United States
| | - De-Ming Chau
- Molecular
Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, New York 10065, United States
- Clinical
Genetics Unit Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Selangor, Malaysia
| | - Yue-Ming Li
- Molecular
Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, New York 10065, United States
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12
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Ran Y, Ladd GZ, Ceballos-Diaz C, Jung JI, Greenbaum D, Felsenstein KM, Golde TE. Differential Inhibition of Signal Peptide Peptidase Family Members by Established γ-Secretase Inhibitors. PLoS One 2015; 10:e0128619. [PMID: 26046535 PMCID: PMC4457840 DOI: 10.1371/journal.pone.0128619] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Accepted: 04/29/2015] [Indexed: 11/19/2022] Open
Abstract
The signal peptide peptidases (SPPs) are biomedically important proteases implicated as therapeutic targets for hepatitis C (human SPP, (hSPP)), plasmodium (Plasmodium SPP (pSPP)), and B-cell immunomodulation and neoplasia (signal peptide peptidase like 2a, (SPPL2a)). To date, no drug-like, selective inhibitors have been reported. We use a recombinant substrate based on the amino-terminus of BRI2 fused to amyloid β 1-25 (Aβ1-25) (FBA) to develop facile, cost-effective SPP/SPPL protease assays. Co-transfection of expression plasmids expressing the FBA substrate with SPP/SPPLs were conducted to evaluate cleavage, which was monitored by ELISA, Western Blot and immunoprecipitation/MALDI-TOF Mass spectrometry (IP/MS). No cleavage is detected in the absence of SPP/SPPL overexpression. Multiple γ-secretase inhibitors (GSIs) and (Z-LL)2 ketone differentially inhibited SPP/SPPL activity; for example, IC50 of LY-411,575 varied from 51±79 nM (on SPPL2a) to 5499±122 nM (on SPPL2b), while Compound E showed inhibition only on hSPP with IC50 of 1465±93 nM. Data generated were predictive of effects observed for endogenous SPPL2a cleavage of CD74 in a murine B-Cell line. Thus, it is possible to differentially inhibit SPP family members. These SPP/SPPL cleavage assays will expedite the search for selective inhibitors. The data also reinforce similarities between SPP family member cleavage and cleavage catalyzed by γ-secretase.
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Affiliation(s)
- Yong Ran
- Department of Neuroscience, Center for Translational Research in Neurodegenerative Disease, and McKnight Brain Institute, College of Medicine University of Florida, Gainesville, Florida, United States of America
- * E-mail: (YR); (TG)
| | - Gabriela Z. Ladd
- College of Pharmacy, University of Florida, Gainesville, Florida, United States of America
| | - Carolina Ceballos-Diaz
- Department of Neuroscience, Center for Translational Research in Neurodegenerative Disease, and McKnight Brain Institute, College of Medicine University of Florida, Gainesville, Florida, United States of America
| | - Joo In Jung
- Department of Neuroscience, Center for Translational Research in Neurodegenerative Disease, and McKnight Brain Institute, College of Medicine University of Florida, Gainesville, Florida, United States of America
| | - Doron Greenbaum
- Pennsylvania Drug Discovery Institute, Philadelphia, Pennsylvania, United States of America
| | - Kevin M. Felsenstein
- Department of Neuroscience, Center for Translational Research in Neurodegenerative Disease, and McKnight Brain Institute, College of Medicine University of Florida, Gainesville, Florida, United States of America
| | - Todd E. Golde
- Department of Neuroscience, Center for Translational Research in Neurodegenerative Disease, and McKnight Brain Institute, College of Medicine University of Florida, Gainesville, Florida, United States of America
- * E-mail: (YR); (TG)
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13
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Mentrup T, Häsler R, Fluhrer R, Saftig P, Schröder B. A Cell-Based Assay Reveals Nuclear Translocation of Intracellular Domains Released by SPPL Proteases. Traffic 2015; 16:871-92. [DOI: 10.1111/tra.12287] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Revised: 03/26/2015] [Accepted: 03/26/2015] [Indexed: 12/27/2022]
Affiliation(s)
- Torben Mentrup
- Biochemical Institute; Christian Albrechts University of Kiel; Otto-Hahn-Platz 9 D-24118 Kiel Germany
| | - Robert Häsler
- Institute of Clinical Molecular Biology; Christian Albrechts University of Kiel; Schittenhelmstr. 12 D-24105 Kiel Germany
| | - Regina Fluhrer
- Biomedizinisches Centrum (BMC); Ludwig Maximilians University of Munich; Feodor-Lynen-Strasse 17 D-81377 Munich Germany
- DZNE - German Center for Neurodegenerative Diseases; Feodor-Lynen-Strasse 17 D-81377 Munich Germany
| | - Paul Saftig
- Biochemical Institute; Christian Albrechts University of Kiel; Otto-Hahn-Platz 9 D-24118 Kiel Germany
| | - Bernd Schröder
- Biochemical Institute; Christian Albrechts University of Kiel; Otto-Hahn-Platz 9 D-24118 Kiel Germany
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14
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Voss M, Künzel U, Higel F, Kuhn PH, Colombo A, Fukumori A, Haug-Kröper M, Klier B, Grammer G, Seidl A, Schröder B, Obst R, Steiner H, Lichtenthaler SF, Haass C, Fluhrer R. Shedding of glycan-modifying enzymes by signal peptide peptidase-like 3 (SPPL3) regulates cellular N-glycosylation. EMBO J 2014; 33:2890-905. [PMID: 25354954 DOI: 10.15252/embj.201488375] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Protein N-glycosylation is involved in a variety of physiological and pathophysiological processes such as autoimmunity, tumour progression and metastasis. Signal peptide peptidase-like 3 (SPPL3) is an intramembrane-cleaving aspartyl protease of the GxGD type. Its physiological function, however, has remained enigmatic, since presently no physiological substrates have been identified. We demonstrate that SPPL3 alters the pattern of cellular N-glycosylation by triggering the proteolytic release of active site-containing ectodomains of glycosidases and glycosyltransferases such as N-acetylglucosaminyltransferase V, β-1,3 N-acetylglucosaminyltransferase 1 and β-1,4 galactosyltransferase 1. Cleavage of these enzymes leads to a reduction in their cellular activity. In line with that, reduced expression of SPPL3 results in a hyperglycosylation phenotype, whereas elevated SPPL3 expression causes hypoglycosylation. Thus, SPPL3 plays a central role in an evolutionary highly conserved post-translational process in eukaryotes.
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Affiliation(s)
- Matthias Voss
- Adolf Butenandt Institute for Biochemistry, Ludwig-Maximilians University Munich, Munich, Germany
| | - Ulrike Künzel
- Adolf Butenandt Institute for Biochemistry, Ludwig-Maximilians University Munich, Munich, Germany
| | - Fabian Higel
- Sandoz Biopharmaceuticals/HEXAL AG, Oberhaching, Germany
| | - Peer-Hendrik Kuhn
- DZNE - German Center for Neurodegenerative Diseases, Munich, Germany Institute for Advanced Study, Technische Universität München, Garching, Germany
| | - Alessio Colombo
- DZNE - German Center for Neurodegenerative Diseases, Munich, Germany
| | - Akio Fukumori
- DZNE - German Center for Neurodegenerative Diseases, Munich, Germany
| | - Martina Haug-Kröper
- Adolf Butenandt Institute for Biochemistry, Ludwig-Maximilians University Munich, Munich, Germany
| | - Bärbel Klier
- DZNE - German Center for Neurodegenerative Diseases, Munich, Germany
| | - Gudula Grammer
- Adolf Butenandt Institute for Biochemistry, Ludwig-Maximilians University Munich, Munich, Germany
| | - Andreas Seidl
- Sandoz Biopharmaceuticals/HEXAL AG, Oberhaching, Germany
| | - Bernd Schröder
- Biochemical Institute, Christian-Albrechts-University Kiel, Kiel, Germany
| | - Reinhard Obst
- Institute for Immunology, Ludwig-Maximilians University Munich, Munich, Germany
| | - Harald Steiner
- Adolf Butenandt Institute for Biochemistry, Ludwig-Maximilians University Munich, Munich, Germany DZNE - German Center for Neurodegenerative Diseases, Munich, Germany
| | - Stefan F Lichtenthaler
- DZNE - German Center for Neurodegenerative Diseases, Munich, Germany Munich Cluster for Systems Neurology (SyNergy), Munich, Germany Neuroproteomics, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
| | - Christian Haass
- Adolf Butenandt Institute for Biochemistry, Ludwig-Maximilians University Munich, Munich, Germany DZNE - German Center for Neurodegenerative Diseases, Munich, Germany Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Regina Fluhrer
- Adolf Butenandt Institute for Biochemistry, Ludwig-Maximilians University Munich, Munich, Germany DZNE - German Center for Neurodegenerative Diseases, Munich, Germany
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15
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Baldwin M, Russo C, Li X, Chishti AH. Plasmodium falciparum signal peptide peptidase cleaves malaria heat shock protein 101 (HSP101). Implications for gametocytogenesis. Biochem Biophys Res Commun 2014; 450:1427-32. [PMID: 25017910 DOI: 10.1016/j.bbrc.2014.07.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2014] [Accepted: 07/02/2014] [Indexed: 10/25/2022]
Abstract
Previously we described the identification of a Plasmodium falciparum signal peptide peptidase (PfSPP) functioning at the blood stage of malaria infection. Our studies also demonstrated that mammalian SPP inhibitors prevent malaria parasite growth at the late-ring/early trophozoite stage of intra-erythrocytic development. Consistent with its role in development, we tested the hypothesis that PfSPP functions at the endoplasmic reticulum of P.falciparum where it cleaves membrane-bound signal peptides generated following the enzyme activity of signal peptidase. The localization of PfSPP to the endoplasmic reticulum was confirmed by immunofluorescence microscopy and immunogold electron microscopy. Biochemical analysis indicated the existence of monomer and dimer forms of PfSPP in the parasite lysate. A comprehensive bioinformatics screen identified several candidate PfSPP substrates in the parasite genome. Using an established transfection based in vivo luminescence assay, malaria heat shock protein 101 (HSP101) was identified as a substrate of PfSPP, and partial inhibition of PfSPP correlated with the emergence of gametocytes. This finding unveils the first known substrate of PfSPP, and provides new perspectives for the function of intra-membrane proteolysis at the erythrocyte stage of malaria parasite life cycle.
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Affiliation(s)
- Michael Baldwin
- Department of Developmental, Molecular & Chemical Biology, Tufts University School of Medicine, Boston, MA 02111, United States
| | - Crystal Russo
- Department of Developmental, Molecular & Chemical Biology, Tufts University School of Medicine, Boston, MA 02111, United States
| | - Xuerong Li
- Department of Developmental, Molecular & Chemical Biology, Tufts University School of Medicine, Boston, MA 02111, United States
| | - Athar H Chishti
- Department of Developmental, Molecular & Chemical Biology, Tufts University School of Medicine, Boston, MA 02111, United States; Sackler School of Graduate Biomedical Sciences, Programs in Physiology, Pharmacology, and Microbiology, Tufts University School of Medicine, Boston, MA 02111, United States.
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16
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Tomita T. Secretase inhibitors and modulators for Alzheimer’s disease treatment. Expert Rev Neurother 2014; 9:661-79. [DOI: 10.1586/ern.09.24] [Citation(s) in RCA: 109] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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17
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Voss M, Schröder B, Fluhrer R. Mechanism, specificity, and physiology of signal peptide peptidase (SPP) and SPP-like proteases. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2013; 1828:2828-39. [PMID: 24099004 DOI: 10.1016/j.bbamem.2013.03.033] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2012] [Revised: 03/25/2013] [Accepted: 03/29/2013] [Indexed: 01/09/2023]
Abstract
Signal peptide peptidase (SPP) and the homologous SPP-like (SPPL) proteases SPPL2a, SPPL2b, SPPL2c and SPPL3 belong to the family of GxGD intramembrane proteases. SPP/SPPLs selectively cleave transmembrane domains in type II orientation and do not require additional co-factors for proteolytic activity. Orthologues of SPP and SPPLs have been identified in other vertebrates, plants, and eukaryotes. In line with their diverse subcellular localisations ranging from the ER (SPP, SPPL2c), the Golgi (SPPL3), the plasma membrane (SPPL2b) to lysosomes/late endosomes (SPPL2a), the different members of the SPP/SPPL family seem to exhibit distinct functions. Here, we review the substrates of these proteases identified to date as well as the current state of knowledge about the physiological implications of these proteolytic events as deduced from in vivo studies. Furthermore, the present knowledge on the structure of intramembrane proteases of the SPP/SPPL family, their cleavage mechanism and their substrate requirements are summarised. This article is part of a Special Issue entitled: Intramembrane Proteases.
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Affiliation(s)
- Matthias Voss
- Adolf Butenandt Institute for Biochemistry, Ludwig-Maximilians University Munich, Schillerstr. 44, 80336 Munich, Germany
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18
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Golde TE, Koo EH, Felsenstein KM, Osborne BA, Miele L. γ-Secretase inhibitors and modulators. BIOCHIMICA ET BIOPHYSICA ACTA 2013; 1828:2898-907. [PMID: 23791707 PMCID: PMC3857966 DOI: 10.1016/j.bbamem.2013.06.005] [Citation(s) in RCA: 210] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Accepted: 06/04/2013] [Indexed: 12/11/2022]
Abstract
γ-Secretase is a fascinating, multi-subunit, intramembrane cleaving protease that is now being considered as a therapeutic target for a number of diseases. Potent, orally bioavailable γ-secretase inhibitors (GSIs) have been developed and tested in humans with Alzheimer's disease (AD) and cancer. Preclinical studies also suggest the therapeutic potential for GSIs in other disease conditions. However, due to inherent mechanism based-toxicity of non-selective inhibition of γ-secretase, clinical development of GSIs will require empirical testing with careful evaluation of benefit versus risk. In addition to GSIs, compounds referred to as γ-secretase modulators (GSMs) remain in development as AD therapeutics. GSMs do not inhibit γ-secretase, but modulate γ-secretase processivity and thereby shift the profile of the secreted amyloid β peptides (Aβ) peptides produced. Although GSMs are thought to have an inherently safe mechanism of action, their effects on substrates other than the amyloid β protein precursor (APP) have not been extensively investigated. Herein, we will review the current state of development of GSIs and GSMs and explore pertinent biological and pharmacological questions pertaining to the use of these agents for select indications. This article is part of a Special Issue entitled: Intramembrane Proteases.
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Affiliation(s)
- Todd E Golde
- Center for Translational Research in Neurodegenerative Disease, Department of Neuroscience, McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, FL 32610, USA.
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19
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van Kasteren SI, Overkleeft H, Ovaa H, Neefjes J. Chemical biology of antigen presentation by MHC molecules. Curr Opin Immunol 2013; 26:21-31. [PMID: 24556397 DOI: 10.1016/j.coi.2013.10.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Accepted: 10/03/2013] [Indexed: 11/25/2022]
Abstract
MHC class I and MHC class II molecules present peptides to the immune system to drive proper T cell responses. Pharmacological modulation of T-cell responses can offer treatment options for a range of immune-related diseases. Pharmacological downregulation of MHC molecules may find application in treatment of auto-immunity and transplantation rejection while pharmacological activation of antigen presentation would support immune responses to infection and cancer. Since the cell biology of MHC class I and MHC class II antigen presentation is understood in great detail, many potential targets for manipulation have been defined over the years. Here, we discuss how antigen presentation by MHC molecules can be modulated by pharmacological agents and how chemistry can further support the study of antigen presentation in general. The chemical biology of antigen presentation by MHC molecules shows surprising options for immune modulation and the development of future therapies.
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Affiliation(s)
- Sander I van Kasteren
- The Netherlands Cancer Institute, Division of Cell Biology, Plesmanlaan 121, Amsterdam, Netherlands; Leiden Institute of Chemistry (LIC), Division of Bio-Organic Chemistry, Einsteinweg 55, Leiden, Netherlands
| | - Hermen Overkleeft
- The Netherlands Cancer Institute, Division of Cell Biology, Plesmanlaan 121, Amsterdam, Netherlands; Leiden Institute of Chemistry (LIC), Division of Bio-Organic Chemistry, Einsteinweg 55, Leiden, Netherlands
| | - Huib Ovaa
- The Netherlands Cancer Institute, Division of Cell Biology, Plesmanlaan 121, Amsterdam, Netherlands; Leiden Institute of Chemistry (LIC), Division of Bio-Organic Chemistry, Einsteinweg 55, Leiden, Netherlands
| | - Jacques Neefjes
- The Netherlands Cancer Institute, Division of Cell Biology, Plesmanlaan 121, Amsterdam, Netherlands; Leiden Institute of Chemistry (LIC), Division of Bio-Organic Chemistry, Einsteinweg 55, Leiden, Netherlands.
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20
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Imamura Y, Umezawa N, Osawa S, Shimada N, Higo T, Yokoshima S, Fukuyama T, Iwatsubo T, Kato N, Tomita T, Higuchi T. Effect of Helical Conformation and Side Chain Structure on γ-Secretase Inhibition by β-Peptide Foldamers: Insight into Substrate Recognition. J Med Chem 2013; 56:1443-54. [DOI: 10.1021/jm301306c] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Yuki Imamura
- Department of Bioorganic-Inorganic
Chemistry, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku,
Nagoya, Aichi, Japan
| | - Naoki Umezawa
- Department of Bioorganic-Inorganic
Chemistry, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku,
Nagoya, Aichi, Japan
| | - Satoko Osawa
- Department
of Neuropathology
and Neuroscience, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo,
Japan
| | - Naoaki Shimada
- Department of Synthetic
Natural
Products Chemistry, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo,
Japan
| | - Takuya Higo
- Department of Synthetic
Natural
Products Chemistry, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo,
Japan
| | - Satoshi Yokoshima
- Department of Synthetic
Natural
Products Chemistry, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo,
Japan
| | - Tohru Fukuyama
- Department of Synthetic
Natural
Products Chemistry, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo,
Japan
| | - Takeshi Iwatsubo
- Department
of Neuropathology
and Neuroscience, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo,
Japan
- Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency, Tokyo, Japan
- Department of Neuropathology,
Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan
| | - Nobuki Kato
- Department of Bioorganic-Inorganic
Chemistry, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku,
Nagoya, Aichi, Japan
| | - Taisuke Tomita
- Department
of Neuropathology
and Neuroscience, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo,
Japan
- Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency, Tokyo, Japan
| | - Tsunehiko Higuchi
- Department of Bioorganic-Inorganic
Chemistry, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku,
Nagoya, Aichi, Japan
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21
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Beisner DR, Langerak P, Parker AE, Dahlberg C, Otero FJ, Sutton SE, Poirot L, Barnes W, Young MA, Niessen S, Wiltshire T, Bodendorf U, Martoglio B, Cravatt B, Cooke MP. The intramembrane protease Sppl2a is required for B cell and DC development and survival via cleavage of the invariant chain. ACTA ACUST UNITED AC 2012; 210:23-30. [PMID: 23267013 PMCID: PMC3549714 DOI: 10.1084/jem.20121072] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
B cell development requires tight regulation to allow for the generation of a diverse repertoire while preventing the development of autoreactive cells. We report, using N-ethyl-N-nitrosourea (ENU)-induced mutagenesis, the identification of a mutant mouse (chompB) with a block in early B cell development. The blockade occurs after the transitional 1 (T1) stage and leads to a decrease in mature B cell subsets and deficits in T cell-dependent antibody responses. Additionally, chompB mice have decreases in myeloid dendritic cells (DCs). The mutation was mapped to the intramembrane protease signal peptide peptidase-like 2a (Sppl2a), a gene not previously implicated in immune cell development. Proteomic analysis identified the invariant chain (CD74) as a key substrate of Sppl2a and suggests that regulated intramembrane proteolysis of CD74 by Sppl2a contributes to B cell and DC survival. Moreover, these data suggest that modulation of Sppl2a may be a useful therapeutic strategy for treatment of B cell dependent autoimmune disorders.
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Affiliation(s)
- Daniel R Beisner
- Genomics Institute of the Novartis Research Foundation, San Diego, CA 92121, USA
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22
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Voss M, Fukumori A, Kuhn PH, Künzel U, Klier B, Grammer G, Haug-Kröper M, Kremmer E, Lichtenthaler SF, Steiner H, Schröder B, Haass C, Fluhrer R. Foamy virus envelope protein is a substrate for signal peptide peptidase-like 3 (SPPL3). J Biol Chem 2012; 287:43401-9. [PMID: 23132852 DOI: 10.1074/jbc.m112.371369] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Signal peptide peptidase (SPP), its homologs, the SPP-like proteases SPPL2a/b/c and SPPL3, as well as presenilin, the catalytic subunit of the γ-secretase complex, are intramembrane-cleaving aspartyl proteases of the GxGD type. In this study, we identified the 18-kDa leader peptide (LP18) of the foamy virus envelope protein (FVenv) as a new substrate for intramembrane proteolysis by human SPPL3 and SPPL2a/b. In contrast to SPPL2a/b and γ-secretase, which require substrates with an ectodomain shorter than 60 amino acids for efficient intramembrane proteolysis, SPPL3 cleaves mutant FVenv lacking the proprotein convertase cleavage site necessary for the prior shedding. Moreover, the cleavage product of FVenv generated by SPPL3 serves as a new substrate for consecutive intramembrane cleavage by SPPL2a/b. Thus, human SPPL3 is the first GxGD-type aspartyl protease shown to be capable of acting like a sheddase, similar to members of the rhomboid family, which belong to the class of intramembrane-cleaving serine proteases.
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Affiliation(s)
- Matthias Voss
- Adolf Butenandt Institute for Biochemistry, Ludwig-Maximilians University Munich, 80336 Munich, Germany
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23
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Membrane proteases in the bacterial protein secretion and quality control pathway. Microbiol Mol Biol Rev 2012; 76:311-30. [PMID: 22688815 DOI: 10.1128/mmbr.05019-11] [Citation(s) in RCA: 107] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Proteolytic cleavage of proteins that are permanently or transiently associated with the cytoplasmic membrane is crucially important for a wide range of essential processes in bacteria. This applies in particular to the secretion of proteins and to membrane protein quality control. Major progress has been made in elucidating the structure-function relationships of many of the responsible membrane proteases, including signal peptidases, signal peptide hydrolases, FtsH, the rhomboid protease GlpG, and the site 1 protease DegS. These enzymes employ very different mechanisms to cleave substrates at the cytoplasmic and extracytoplasmic membrane surfaces or within the plane of the membrane. This review highlights the different ways that bacterial membrane proteases degrade their substrates, with special emphasis on catalytic mechanisms and substrate delivery to the respective active sites.
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24
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Marapana DS, Wilson DW, Zuccala ES, Dekiwadia CD, Beeson JG, Ralph SA, Baum J. Malaria parasite signal peptide peptidase is an ER-resident protease required for growth but not for invasion. Traffic 2012; 13:1457-65. [PMID: 22844982 DOI: 10.1111/j.1600-0854.2012.01402.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2012] [Revised: 07/25/2012] [Accepted: 07/27/2012] [Indexed: 11/28/2022]
Abstract
The establishment of parasite infection within the human erythrocyte is an essential stage in the development of malaria disease. As such, significant interest has focused on the mechanics that underpin invasion and on characterization of parasite molecules involved. Previous evidence has implicated a presenilin-like signal peptide peptidase (SPP) from the most virulent human malaria parasite, Plasmodium falciparum, in the process of invasion where it has been proposed to function in the cleavage of the erythrocyte cytoskeletal protein Band 3. The role of a traditionally endoplasmic reticulum (ER) protease in the process of red blood cell invasion is unexpected. Here, using a combination of molecular, cellular and chemical approaches we provide evidence that PfSPP is, instead, a bona fide ER-resident peptidase that remains intracellular throughout the invasion process. Furthermore, SPP-specific drug inhibition has no effect on erythrocyte invasion whilst having low micromolar potency against intra-erythrocytic development. Contrary to previous reports, these results show that PfSPP plays no role in erythrocyte invasion. Nonetheless, PfSPP clearly represents a potential chemotherapeutic target to block parasite growth, supporting ongoing efforts to develop antimalarial-targeting protein maturation and trafficking during intra-erythrocytic development.
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Affiliation(s)
- Danushka S Marapana
- Infection and Immunity, Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia
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25
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Fraering PC. Structural and Functional Determinants of gamma-Secretase, an Intramembrane Protease Implicated in Alzheimer's Disease. Curr Genomics 2011; 8:531-49. [PMID: 19415127 PMCID: PMC2647162 DOI: 10.2174/138920207783769521] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2007] [Revised: 12/27/2007] [Accepted: 12/27/2007] [Indexed: 12/28/2022] Open
Abstract
Alzheimer’s disease is the most common form of neurodegenerative diseases in humans, characterized by the progressive accumulation and aggregation of amyloid-β peptides (Aβ) in brain regions subserving memory and cognition. These 39-43 amino acids long peptides are generated by the sequential proteolytic cleavages of the amyloid-β precursor protein (APP) by β- and γ-secretases, with the latter being the founding member of a new class of intramembrane-cleaving proteases (I-CliPs) characterized by their intramembranous catalytic residues hydrolyzing the peptide bonds within the transmembrane regions of their respective substrates. These proteases include the S2P family of metalloproteases, the Rhomboid family of serine proteases, and two aspartyl proteases: the signal peptide peptidase (SPP) and γ-secretase. In sharp contrast to Rhomboid and SPP that function as a single component, γ-secretase is a multi-component protease with complex assembly, maturation and activation processes. Recently, two low-resolution three-dimensional structures of γ-secretase and three high-resolution structures of the GlpG rhomboid protease have been obtained almost simultaneously by different laboratories. Although these proteases are unrelated by sequence or evolution, they seem to share common functional and structural mechanisms explaining how they catalyze intramembrane proteolysis. Indeed, a water-containing chamber in the catalytic cores of both γ-secretase and GlpG rhomboid provides the hydrophilic environment required for proteolysis and a lateral gating mechanism controls substrate access to the active site. The studies that have identified and characterized the structural determinants critical for the assembly and activity of the γ-secretase complex are reviewed here.
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Affiliation(s)
- Patrick C Fraering
- Brain Mind Institute and School of Life Sciences, Swiss Federal Institute of Technology (EPFL), CH-1015 Lausanne, Switzerland
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26
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Miyashita H, Maruyama Y, Isshiki H, Osawa S, Ogura T, Mio K, Sato C, Tomita T, Iwatsubo T. Three-dimensional structure of the signal peptide peptidase. J Biol Chem 2011; 286:26188-97. [PMID: 21636854 DOI: 10.1074/jbc.m111.260273] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Signal peptide peptidase (SPP) is an atypical aspartic protease that hydrolyzes peptide bonds within the transmembrane domain of substrates and is implicated in several biological and pathological functions. Here, we analyzed the structure of human SPP by electron microscopy and reconstructed the three-dimensional structure at a resolution of 22 Å. Enzymatically active SPP forms a slender, bullet-shaped homotetramer with dimensions of 85 × 85 × 130 Å. The SPP complex has four concaves on the rhombus-like sides, connected to a large chamber inside the molecule. Intriguingly, the N-terminal region of SPP is sufficient for the tetrameric assembly. Moreover, overexpression of the N-terminal region inhibited the formation of the endogenous SPP tetramer and the proteolytic activity within cells. These data suggest that the homotetramer is the functional unit of SPP and that its N-terminal region, which works as the structural scaffold, has a novel modulatory function for the intramembrane-cleaving activity of SPP.
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Affiliation(s)
- Hiroyuki Miyashita
- Department of Neuropathology and Neuroscience, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan
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Imamura Y, Watanabe N, Umezawa N, Iwatsubo T, Kato N, Tomita T, Higuchi T. Inhibition of γ-Secretase Activity by Helical β-Peptide Foldamers. J Am Chem Soc 2009; 131:7353-9. [DOI: 10.1021/ja9001458] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Yuki Imamura
- Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya, Aichi 467-8603, and Graduate School of Pharmaceutical Sciences, Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Corporation, and Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033
| | - Naoto Watanabe
- Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya, Aichi 467-8603, and Graduate School of Pharmaceutical Sciences, Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Corporation, and Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033
| | - Naoki Umezawa
- Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya, Aichi 467-8603, and Graduate School of Pharmaceutical Sciences, Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Corporation, and Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033
| | - Takeshi Iwatsubo
- Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya, Aichi 467-8603, and Graduate School of Pharmaceutical Sciences, Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Corporation, and Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033
| | - Nobuki Kato
- Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya, Aichi 467-8603, and Graduate School of Pharmaceutical Sciences, Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Corporation, and Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033
| | - Taisuke Tomita
- Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya, Aichi 467-8603, and Graduate School of Pharmaceutical Sciences, Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Corporation, and Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033
| | - Tsunehiko Higuchi
- Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya, Aichi 467-8603, and Graduate School of Pharmaceutical Sciences, Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Corporation, and Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033
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Golde TE, Wolfe MS, Greenbaum DC. Signal peptide peptidases: a family of intramembrane-cleaving proteases that cleave type 2 transmembrane proteins. Semin Cell Dev Biol 2009; 20:225-30. [PMID: 19429495 DOI: 10.1016/j.semcdb.2009.02.003] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2009] [Revised: 02/05/2009] [Accepted: 02/05/2009] [Indexed: 01/09/2023]
Abstract
Five genes encode the five human signal peptide peptidases (SPPs), which are intramembrane-cleaving aspartyl proteases (aspartyl I-CLiPs). SPPs have been conserved through evolution with family members found in higher eukaryotes, fungi, protozoa, arachea, and plants. SPPs are related to the presenilin family of aspartyl I-CLiPs but differ in several key aspects. Presenilins (PSENs) and SPPs both cleave the transmembrane region of membrane proteins; however, PSENs cleave type 1 membrane proteins whereas SPPs cleave type 2 membrane proteins. Though the overall homology between SPPs and PSENs is minimal, they are multipass membrane proteins that contain two conserved active site motifs YD and GxGD in adjacent membrane-spanning domains and a conserved PAL motif of unknown function near their COOH-termini. They differ in that the active site YD and GxGD containing transmembrane domains of SPPs are inverted relative to PSENs, thus, orienting the active site in a consistent topology relative to the substrate. At least two of the human SPPs (SPP and SPPL3) appear to function without additional cofactors, but PSENs function as a protease, called gamma-secretase, only when complexed with Nicastrin, APH-1 and Pen-2. The biological roles of SPP are largely unknown, and only a few endogenous substrates for SPPs have been identified. Nevertheless there is emerging evidence that SPP family members are highly druggable and may regulate both essential physiologic and pathophysiologic processes. Further study of the SPP family is needed in order to understand their biological roles and their potential as therapeutic targets.
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Affiliation(s)
- Todd E Golde
- Department of Neuroscience, Mayo Clinic, College of Medicine, 4500 San Pablo Road, Jacksonville, FL 32224, United States.
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Fluhrer R, Steiner H, Haass C. Intramembrane proteolysis by signal peptide peptidases: a comparative discussion of GXGD-type aspartyl proteases. J Biol Chem 2009; 284:13975-9. [PMID: 19189970 DOI: 10.1074/jbc.r800040200] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Intramembrane-cleaving proteases are required for reverse signaling and membrane protein degradation. A major class of these proteases is represented by the GXGD-type aspartyl proteases. GXGD describes a novel signature sequence that distinguishes these proteases from conventional aspartyl proteases. Members of the family of the GXGD-type aspartyl proteases are the Alzheimer disease-related gamma-secretase, the signal peptide peptidases and their homologs, and the bacterial type IV prepilin peptidases. We will describe the major biochemical and functional properties of the signal peptide peptidases and their relatives. We then compare these properties with those of gamma-secretase and discuss common mechanisms but also point out a number of substantial differences.
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Affiliation(s)
- Regina Fluhrer
- Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE) and Adolf Butenandt Institute, Biochemistry, Ludwig-Maximilians University, Munich, 80336 Munich, Germany.
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Robakis T, Bak B, Lin SH, Bernard DJ, Scheiffele P. An internal signal sequence directs intramembrane proteolysis of a cellular immunoglobulin domain protein. J Biol Chem 2008; 283:36369-76. [PMID: 18981173 DOI: 10.1074/jbc.m807527200] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Precursor proteolysis is a crucial mechanism for regulating protein structure and function. Signal peptidase (SP) is an enzyme with a well defined role in cleaving N-terminal signal sequences but no demonstrated function in the proteolysis of cellular precursor proteins. We provide evidence that SP mediates intraprotein cleavage of IgSF1, a large cellular Ig domain protein that is processed into two separate Ig domain proteins. In addition, our results suggest the involvement of signal peptide peptidase (SPP), an intramembrane protease, which acts on substrates that have been previously cleaved by SP. We show that IgSF1 is processed through sequential proteolysis by SP and SPP. Cleavage is directed by an internal signal sequence and generates two separate Ig domain proteins from a polytopic precursor. Our findings suggest that SP and SPP function are not restricted to N-terminal signal sequence cleavage but also contribute to the processing of cellular transmembrane proteins.
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Affiliation(s)
- Thalia Robakis
- Department of Physiology & Cellular Biophysics, Columbia University, New York, New York 10032, USA
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31
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Tolia A, Horré K, De Strooper B. Transmembrane domain 9 of presenilin determines the dynamic conformation of the catalytic site of gamma-secretase. J Biol Chem 2008; 283:19793-803. [PMID: 18482978 DOI: 10.1074/jbc.m802461200] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
One of the most prominent drug targets for the treatment of Alzheimer disease is gamma-secretase, a multi-protein complex responsible for the generation of the amyloid-beta peptide. The catalytic core of the complex lies on presenilin, a multi-spanning membrane protease, the activity of which depends on two aspartate residues located in transmembrane domains 6 and 7. We have recently shown by cysteine-scanning mutagenesis that these aspartates are facing a water-filled cavity in the lipid bilayer, demonstrating how proteolytic cleavage of the substrates can be taking place within the membrane. Here, we demonstrate that transmembrane domain 9 and hydrophobic domain VII in the large cytoplasmic loop of presenilin are dynamic structural parts of this cavity. Hydrophobic domain VII is associated with transmembrane domain 7 in the membrane, probably facilitating the entrance of water molecules in the catalytic site. Transmembrane domain 9, on the other hand, exhibits a highly flexible structure, potentially involved in the transport of substrates to the catalytic site, as well as in the binding of gamma-secretase inhibitors. The conserved proline-alanine-leucine motif at the cytoplasmic part of this domain is extremely close to the catalytic Asp257 and is crucial for conformational changes leading to the activation of the catalytic site. We, also, identify a unique mutant in this domain (I437C) that specifically blocks amyloid-beta peptide production without affecting the processing of the physiologically indispensable Notch substrate. Our data are finally combined to propose a model for the architectural organization and activation of the catalytic site of presenilin.
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Affiliation(s)
- Alexandra Tolia
- Department for Molecular and Developmental Genetics, VIB (Vlaams Instituut voor Biotechnologie), Belgium
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Abstract
Gamma-Secretase is a promiscuous protease that cleaves bitopic membrane proteins within the lipid bilayer. Elucidating both the mechanistic basis of gamma-secretase proteolysis and the precise factors regulating substrate identification is important because modulation of this biochemical degradative process can have important consequences in a physiological and pathophysiological context. Here, we briefly review such information for all major classes of intramembranously cleaving proteases (I-CLiPs), with an emphasis on gamma-secretase, an I-CLiP closely linked to the etiology of Alzheimer's disease. A large body of emerging data allows us to survey the substrates of gamma-secretase to ascertain the conformational features that predispose a peptide to cleavage by this enigmatic protease. Because substrate specificity in vivo is closely linked to the relative subcellular compartmentalization of gamma-secretase and its substrates, we also survey the voluminous body of literature concerning the traffic of gamma-secretase and its most prominent substrate, the amyloid precursor protein.
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Affiliation(s)
- A. J. Beel
- Department of Biochemistry and Center for Structural Biology, Vanderbilt University School of Medicine, Rm. 5142 MRBIII, 21st Ave. S., Nashville, Tennessee 37232-8725 USA
| | - C. R. Sanders
- Department of Biochemistry and Center for Structural Biology, Vanderbilt University School of Medicine, Rm. 5142 MRBIII, 21st Ave. S., Nashville, Tennessee 37232-8725 USA
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Iben LG, Olson RE, Balanda LA, Jayachandra S, Robertson BJ, Hay V, Corradi J, Prasad C, Zaczek R, Albright CF, Toyn JH. Signal Peptide Peptidase and γ-Secretase Share Equivalent Inhibitor Binding Pharmacology. J Biol Chem 2007; 282:36829-36. [DOI: 10.1074/jbc.m707002200] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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Narayanan S, Sato T, Wolfe MS. A C-terminal Region of Signal Peptide Peptidase Defines a Functional Domain for Intramembrane Aspartic Protease Catalysis. J Biol Chem 2007; 282:20172-9. [PMID: 17517891 DOI: 10.1074/jbc.m701536200] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Intramembrane proteolysis is now firmly established as a prominent biological process, and structure elucidation is emerging as the new frontier in the understanding of these novel membrane-embedded enzymes. Reproducing this unusual hydrolysis within otherwise water-excluding transmembrane regions with purified proteins is a challenging prerequisite for such structural studies. Here we show the bacterial expression, purification, and reconstitution of proteolytically active signal peptide peptidase (SPP), a membrane-embedded enzyme in the presenilin family of aspartyl proteases. This finding formally proves that, unlike presenilin, SPP does not require any additional proteins for proteolysis. Surprisingly, the conserved C-terminal half of SPP is sufficient for proteolytic activity; purification and reconstitution of this engineered fragment of several SPP orthologues revealed that this region defines a functional domain for an intramembrane aspartyl protease. The discovery of minimal requirements for intramembrane proteolysis should facilitate mechanistic and structural analysis and help define general biochemical principles of hydrolysis in a hydrophobic environment.
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Affiliation(s)
- Saravanakumar Narayanan
- Center for Neurologic Diseases, Brigham and Women's Hospital and Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA 02115, USA
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36
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Fluhrer R, Haass C. Signal Peptide Peptidases and Gamma-Secretase: Cousins of the Same Protease Family? NEURODEGENER DIS 2007; 4:112-6. [PMID: 17596705 DOI: 10.1159/000101835] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Signal peptide peptidase (SPP) is an unusual aspartyl protease, which mediates clearance of signal peptides by proteolysis within the endoplasmic reticulum (ER). Like presenilins, which provide the proteolytically active subunit of the gamma-secretase complex, SPP contains a conserved GxGD motif in its C-terminal domain which is critical for its activity. While SPP is known to be an aspartyl protease of the GxGD type, several presenilin homologues/SPP-like proteins (PSHs/SPPL) of unknown function have been identified by database searches. In contrast to SPP and SPPL3, which are both restricted to the endoplasmic reticulum, SPPL2b is targeted through the secretory pathway to endosomes/lysosomes. As suggested by the differential subcellular localization of SPPL2b and SPPL3 distinct phenotypes were found upon antisense gripNA-mediated knockdown in zebrafish. spp and sppl3 knockdowns in zebrafish result in cell death within the central nervous system, whereas reduction of sppl2b expression causes erythrocyte accumulation in an enlarged caudal vein. Moreover, expression of D/A mutants of the putative C-terminal active sites of spp, sppl2,and sppl3 produced phenocopies of the respective knockdown phenotypes. These data suggest that all investigated PSHs/SPPLs are members of the novel family of GxGD aspartyl proteases. More recently, it was shown that SPPL2b utilizes multiple intramembrane cleavages to liberate the TNFalpha intracellular domain into the cytosol and to release the C-terminal counterpart into the lumen. These findings suggest common principles of intramembrane proteolysis by GxGD type aspartyl proteases. In this article, we will review the similarities of SPPs and gamma-secretase based on recent findings by us and others.
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Affiliation(s)
- Regina Fluhrer
- Adolf-Butenandt-Institute, Department of Biochemistry, Laboratory for Alzheimer's and Parkinson's Disease Research, Ludwig-Maximilians University, Munich, Germany
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Fuwa H, Takahashi Y, Konno Y, Watanabe N, Miyashita H, Sasaki M, Natsugari H, Kan T, Fukuyama T, Tomita T, Iwatsubo T. Divergent synthesis of multifunctional molecular probes to elucidate the enzyme specificity of dipeptidic gamma-secretase inhibitors. ACS Chem Biol 2007; 2:408-18. [PMID: 17530731 DOI: 10.1021/cb700073y] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Divergent synthesis of multifunctional molecular probes based on caprolactam-derived dipeptidic gamma-secretase inhibitors (GSIs), Compound E (CE) and LY411575 analogue (DBZ), was efficiently accomplished by means of Cu(I)-catalyzed azide/alkyne fusion reaction. Photoaffinity labeling experiments using these derivatives coupled to photoactivatable and biotin moieties provided direct evidence that the molecular targets of CE and DBZ are the N-terminal fragment of presenilin 1 within the gamma-secretase complex. Moreover, these photoprobes directly targeted signal peptide peptidase. These data suggest that the divergent synthesis of molecular probes has been successfully applied to characterize the interaction of GSIs with their molecular targets and define the structural requirements for inhibitor binding to intramembrane-cleaving proteases.
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Affiliation(s)
- Haruhiko Fuwa
- Laboratory of Biostructural Chemistry, Graduate School of Life Sciences, Tohoku University, Tsutsumidori-Amamiya, Aoba-ku, Sendai, Japan.
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Nyborg AC, Herl L, Berezovska O, Thomas AV, Ladd TB, Jansen K, Hyman BT, Golde TE. Signal peptide peptidase (SPP) dimer formation as assessed by fluorescence lifetime imaging microscopy (FLIM) in intact cells. Mol Neurodegener 2006; 1:16. [PMID: 17105660 PMCID: PMC1654158 DOI: 10.1186/1750-1326-1-16] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2006] [Accepted: 11/14/2006] [Indexed: 11/13/2022] Open
Abstract
Background Signal peptide peptidase (SPP) is an intramembrane cleaving protease identified by its cleavage of several type II membrane signal peptides. Conservation of intramembrane active site residues demonstrates that SPP, SPP family members, and presenilins (PSs) make up a family of intramembrane cleaving proteases. Because SPP appears to function without additional protein cofactors, the study of SPP may provide structural insights into the mechanism of intramembrane proteolysis by this biomedically important family of proteins. Previous studies have shown that SPP isolated from cells appears to be a homodimer, but some evidence exists that in vitro SPP may be active as a monomer. We have conducted additional experiments to determine if SPP exists as a monomer or dimer in vivo. Results Fluorescence lifetime imaging microscopy (FLIM) can be is used to determine intra- or intermolecular interactions by fluorescently labeling epitopes on one or two different molecules. If the donor and acceptor fluorophores are less than 10 nm apart, the donor fluorophore lifetime shortens proportionally to the distance between the fluorophores. In this study, we used two types of fluorescence energy transfer (FRET) pairs; cyan fluorescent protein (CFP) with yellow fluorescent protein (YFP) or Alexa 488 with Cy3 to differentially label the NH2- or COOH-termini of SPP molecules. A cell based SPP activity assay was used to show that all tagged SPP proteins are proteolytically active. Using FLIM we were able to show that the donor fluorophore lifetime of the CFP tagged SPP construct in living cells significantly decreases when either a NH2- or COOH-terminally YFP tagged SPP construct is co-transfected, indicating close proximity between two different SPP molecules. These data were then confirmed in cell lines stably co-expressing V5- and FLAG-tagged SPP constructs. Conclusion Our FLIM data strongly suggest dimer formation between two separate SPP proteins. Although the tagged SPP constructs are expressed throughout the cell, SPP dimer detection by FLIM is seen predominantly at or near the plasma membrane.
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Affiliation(s)
- Andrew C Nyborg
- Department of Neuroscience, Mayo Clinic Jacksonville, Mayo Clinic College of Medicine, Jacksonville, Florida 32224, USA
| | - Lauren Herl
- Alzheimer's Disease Research Unit, Massachusetts Institute for Neurodegenerative Diseases, Massachusetts General Hospital, Charlestown, Massachusetts 02129, USA
| | - Oksana Berezovska
- Alzheimer's Disease Research Unit, Massachusetts Institute for Neurodegenerative Diseases, Massachusetts General Hospital, Charlestown, Massachusetts 02129, USA
| | - Anne V Thomas
- Alzheimer's Disease Research Unit, Massachusetts Institute for Neurodegenerative Diseases, Massachusetts General Hospital, Charlestown, Massachusetts 02129, USA
| | - Thomas B Ladd
- Department of Neuroscience, Mayo Clinic Jacksonville, Mayo Clinic College of Medicine, Jacksonville, Florida 32224, USA
| | - Karen Jansen
- Department of Neuroscience, Mayo Clinic Jacksonville, Mayo Clinic College of Medicine, Jacksonville, Florida 32224, USA
| | - Bradley T Hyman
- Alzheimer's Disease Research Unit, Massachusetts Institute for Neurodegenerative Diseases, Massachusetts General Hospital, Charlestown, Massachusetts 02129, USA
| | - Todd E Golde
- Department of Neuroscience, Mayo Clinic Jacksonville, Mayo Clinic College of Medicine, Jacksonville, Florida 32224, USA
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Nyborg AC, Ladd TB, Jansen K, Kukar T, Golde TE. Intramembrane proteolytic cleavage by human signal peptide peptidase like 3 and malaria signal peptide peptidase. FASEB J 2006; 20:1671-9. [PMID: 16873890 DOI: 10.1096/fj.06-5762com] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Signal peptide peptidase (SPP) is an intramembrane cleaving protease (I-CLiP) identified by its cleavage of several type II membrane signal peptides. To date, only human SPP has been directly shown to have proteolytic activity. Here we demonstrate that the most closely related human homologue of SPP, signal peptide peptidase like 3 (SPPL3), cleaves a SPP substrate, but a more distantly related homologue, signal peptide peptidase like 2b (SPPL2b), does not. These data provide strong evidence that the SPP and SPPL3 have conserved active sites and suggest that the active sites SPPL2b is distinct. We have also synthesized a cDNA designed to express the single SPP gene present in Plasmodium falciparum and cloned this into a mammalian expression vector. When the malaria SPP protein is expressed in mammalian cells it cleaves a SPP substrate. Notably, several human SPP inhibitors block the proteolytic activity of malarial SPP (mSPP). Studies from several model organisms that express multiple SPP homologs demonstrate that the silencing of a single SPP homologue is lethal. Based on these data, we hypothesize that mSPP is a potential a novel therapeutic target for malaria.
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Affiliation(s)
- Andrew C Nyborg
- Department of Neuroscience, Mayo Clinic Jacksonville, Mayo Clinic College of Medicine, 4500 San Pablo Rd., Jacksonville, Florida 32224, USA
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40
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Dev KK, Chatterjee S, Osinde M, Stauffer D, Morgan H, Kobialko M, Dengler U, Rueeger H, Martoglio B, Rovelli G. Signal peptide peptidase dependent cleavage of type II transmembrane substrates releases intracellular and extracellular signals. Eur J Pharmacol 2006; 540:10-7. [PMID: 16697367 DOI: 10.1016/j.ejphar.2006.04.011] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2005] [Revised: 03/27/2006] [Accepted: 04/03/2006] [Indexed: 10/24/2022]
Abstract
The intramembrane-cleaving proteases (I-CLiPs) presenilin-1 and -2 (PS1 and PS2), signal peptide peptidase (SPP) and the Site-2 protease (S2P) catalyze critical steps in cell signaling and are implicated in diseases such as Alzheimer's disease, hepatitis C virus (HCV) infection and cholesterol homeostasis. Here we describe the development of a cellular assay based on cleavage of the transmembrane sequence of the HCV core protein precursor, releasing intra- and extra-cellular signals that represent sequential signal peptidase and SPP cleavage, respectively. We find that the SPP inhibitor (Z-LL)2-ketone (IC50 = 1.33 microM) and the gamma-secretase potent inhibitors NVP-AHW700-NX (IC50 = 51 nM) and LY411575 (IC50 = 61 nM) but not DAPT dose dependently inhibited SPP but not signal peptidase cleavage. Our data confirm that type II orientated substrates, like the HCV transmembrane sequence, are sequentially cleaved by signal peptidase then SPP. This dual assay provides a powerful tool to pharmacologically analyze sequential cleavage events of signal peptidase and SPP and their regulation.
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Affiliation(s)
- Kumlesh K Dev
- Novartis Institutes for BioMedical Research, Novartis Pharma AG, CH-4002 Basel, Switzerland.
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Urny J, Hermans-Borgmeyer I, Schaller HC. Cell-surface expression of a new splice variant of the mouse signal peptide peptidase. ACTA ACUST UNITED AC 2006; 1759:159-65. [PMID: 16730383 DOI: 10.1016/j.bbaexp.2006.02.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2005] [Revised: 02/17/2006] [Accepted: 02/28/2006] [Indexed: 10/24/2022]
Abstract
The signal peptide peptidase (SPP) is an intramembrane-cleaving aspartyl protease that acts on type II transmembrane proteins. SPP substrates include signal peptides after they have been cleaved from a preprotein, hence the name. The known SPP isoform, which we renamed SPPalpha, contains an endoplasmic reticulum retention signal at the carboxy terminus. We found a new splice variant, SPPbeta, with an additional in-frame exon inserted between exons 11 and 12 of SPPalpha. Insertion of the new exon led to a complete change in the amino-acid sequence of the carboxy tail. A stop codon within this new exon resulted in silencing of exon 12 and eliminated the endoplasmic reticulum retention signal. The new SPP isoform predominantly localised to the cell surface in contrast to the more restricted localisation of SPPalpha in the endoplasmic reticulum. Differential expression in mouse tissues and in subcellular compartments suggests new functions for SPP in addition to cleaving signal peptides.
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Affiliation(s)
- Jens Urny
- Zentrum für Molekulare Neurobiologie, Universität Hamburg, Martinistr. 52, 20246 Hamburg, Germany
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Wang J, Beher D, Nyborg AC, Shearman MS, Golde TE, Goate A. C-terminal PAL motif of presenilin and presenilin homologues required for normal active site conformation. J Neurochem 2006; 96:218-27. [PMID: 16305624 DOI: 10.1111/j.1471-4159.2005.03548.x] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
The Alzheimer's disease-associated beta-amyloid peptide is produced through cleavage of amyloid precursor protein by beta-secretase and gamma-secretase. gamma-Secretase is a complex containing presenilin (PS) as the catalytic component and three essential cofactors: Nicastrin, anterior pharynx defective (APH-1) and presenilin enhancer-2 (PEN-2). PS and signal peptide peptidase (SPP) define a novel family of aspartyl proteases that cleave substrates within the transmembrane domain presumptively using two membrane-embedded aspartic acid residues for catalysis. Apart from the two aspartate-containing active site motifs, the only other region that is conserved between PS and SPP is a PAL sequence at the C-terminus. Although it has been well documented that this motif is essential for gamma-secretase activity, the mechanism underlying such a critical role is not understood. Here we show that mutations in this motif affect the conformation of the active site of gamma-secretase resulting in a complete loss of PS binding to a gamma-secretase transition state analog inhibitor, Merck C. Analogous mutations in SPP significantly inhibit its enzymatic activity. Furthermore, these mutations also abolish SPP binding to Merck C, indicating that SPP and gamma-secretase share a similar active site conformation, which is dependent on the PAL motif. Exploring the amino acid requirements within this motif reveals a very small side chain requirement, which is conserved during evolution. Together, these observations strongly support the hypothesis that the PAL motif contributes to the active site conformation of gamma-secretase and of SPP.
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Affiliation(s)
- Jun Wang
- Department of Psychiatry, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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Becker-Herman S, Arie G, Medvedovsky H, Kerem A, Shachar I. CD74 is a member of the regulated intramembrane proteolysis-processed protein family. Mol Biol Cell 2005; 16:5061-9. [PMID: 16107560 PMCID: PMC1266406 DOI: 10.1091/mbc.e05-04-0327] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Quite a few regulatory proteins, including transcription factors, are normally maintained in a dormant state to be activated after internal or environmental cues. Recently, a novel strategy, requiring proteolytic cleavage, was described for the mobilization of dormant transcription factors. These transcription factors are initially synthesized in an inactive form, whereas "nesting" in integral membrane precursor proteins. After a cleavage event, these new active factors are released from the membrane and can migrate into the nucleus to drive regulated gene transcription. This mechanism, regulated intramembrane proteolysis (RIP), controls diverse biological processes in prokaryotes and eukaryotes in response to a variety of signals. The MHC class II chaperone, CD74 (invariant chain, Ii), was previously shown to function as a signaling molecule in several pathways. Recently, we demonstrated that after intramembranal cleavage, the CD74 cytosolic fragment (CD74-ICD) is released and induces activation of transcription mediated by the NF-kappaB p65/RelA homodimer and the B-cell-enriched coactivator, TAF(II)105. Here, we add CD74 to the growing family of RIP-processed proteins. Our studies show that CD74 ectodomain must be processed in the endocytic compartments to allow its intramembrane cleavage that liberates CD74 intracellular domain (CD74-ICD). We demonstrate that CD74-ICD translocates to the nucleus and induces the activation of the p65 member of NF-kappaB in this compartment.
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Laudon H, Hansson EM, Melén K, Bergman A, Farmery MR, Winblad B, Lendahl U, von Heijne G, Näslund J. A nine-transmembrane domain topology for presenilin 1. J Biol Chem 2005; 280:35352-60. [PMID: 16046406 DOI: 10.1074/jbc.m507217200] [Citation(s) in RCA: 148] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Presenilin (PS) provides the catalytic core of the gamma-secretase complex. Gamma-secretase activity leads to generation of the amyloid beta-peptide, a key event implicated in the pathogenesis of Alzheimer disease. PS has ten hydrophobic regions, which can all theoretically form membrane-spanning domains. Various topology models have been proposed, and the prevalent view holds that PS has an eight-transmembrane (TM) domain organization; however, the precise topology has not been unequivocally determined. Previous topological studies are based on non-functional truncated variants of PS proteins fused to reporter domains, or immunocytochemical staining. In this study, we used a more subtle N-linked glycosylation scanning approach, which allowed us to assess the topology of functional PS1 molecules. Glycosylation acceptor sequences were introduced into full-length human PS1, and the results showed that the first hydrophilic loop is oriented toward the lumen of the endoplasmic reticulum, whereas the N terminus and large hydrophilic loop are in the cytosol. Although this is in accordance with most current models, our data unexpectedly revealed that the C terminus localized to the luminal side of the endoplasmic reticulum. Additional studies on the glycosylation pattern after TM domain deletions, combined with computer-based TM protein topology predictions and biotinylation assays of different PS1 mutants, led us to conclude that PS1 has nine TM domains and that the C terminus locates to the lumen/extracellular space.
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Affiliation(s)
- Hanna Laudon
- Department of Neurotec, Division of Experimental Geriatrics, Karolinska Institutet, Novum, SE-141 86 Huddinge, Sweden.
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Abstract
Our understanding of the classical MHC class I molecules (MHC class Ia molecules) has long focused on their extreme polymorphism. These molecules present peptides to T cells and are central to discrimination between self and non-self. By contrast, the functions of the non-polymorphic MHC class I molecules (MHC class Ib molecules) have been elusive, but emerging evidence reveals that, in addition to antigen presentation, MHC class Ib molecules are involved in immunoregulation. As we discuss here, the subset of MHC class Ib molecules that presents peptides to T cells bridges innate and acquired immunity, and this provides insights into the origins of acquired immunity.
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Affiliation(s)
- John R Rodgers
- Department of Immunology, Baylor College of Medicine, Houston, Texas 77030, USA.
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Crawshaw S, Martoglio B, Meacock S, High S. A misassembled transmembrane domain of a polytopic protein associates with signal peptide peptidase. Biochem J 2005; 384:9-17. [PMID: 15373738 PMCID: PMC1134083 DOI: 10.1042/bj20041216] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The endoplasmic reticulum (ER) exerts a quality control over newly synthesized proteins and a variety of components have been implicated in the specific recognition of aberrant or misfolded polypeptides. We have exploited a site-specific cross-linking approach to search for novel ER components that may specifically recognize the misassembled transmembrane domains present in truncated polytopic proteins. We find that a single probe located in the transmembrane domain of a truncated opsin fragment is cross-linked to several ER proteins. These components are distinct from subunits of the Sec61 complex and represent a 'post-translocon' environment. In this study, we identify one of these post-translocon cross-linking partners as the signal peptide peptidase (SPP). We find that the interaction of truncated opsin chains with SPP is mediated by its second transmembrane domain, and propose that this interaction may contribute to the recognition of misassembled transmembrane domains during membrane protein quality control at the ER.
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Affiliation(s)
- Samuel G. Crawshaw
- *Faculty of Life Sciences, University of Manchester, Michael Smith Building, Oxford Road, Manchester M13 9PT, U.K
| | - Bruno Martoglio
- †Institute of Biochemistry, Swiss Federal Institute of Technology (ETH), ETH-Hoenggerberg, 8093 Zürich, Switzerland
| | - Suzanna L. Meacock
- *Faculty of Life Sciences, University of Manchester, Michael Smith Building, Oxford Road, Manchester M13 9PT, U.K
| | - Stephen High
- *Faculty of Life Sciences, University of Manchester, Michael Smith Building, Oxford Road, Manchester M13 9PT, U.K
- To whom correspondence should be addressed (email )
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Huppert SS, Ilagan MXG, De Strooper B, Kopan R. Analysis of Notch Function in Presomitic Mesoderm Suggests a γ-Secretase-Independent Role for Presenilins in Somite Differentiation. Dev Cell 2005; 8:677-88. [PMID: 15866159 DOI: 10.1016/j.devcel.2005.02.019] [Citation(s) in RCA: 119] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2004] [Revised: 12/23/2004] [Accepted: 02/17/2005] [Indexed: 10/25/2022]
Abstract
The role of Notch signaling in general and presenilin in particular was analyzed during mouse somitogenesis. We visualize cyclical production of activated Notch (NICD) and establish that somitogenesis requires less NICD than any other tissue in early mouse embryos. Indeed, formation of cervical somites proceeds in Notch1; Notch2-deficient embryos. This is in contrast to mice lacking all presenilin alleles, which have no somites. Since Nicastrin-, Pen-2-, and APH-1a-deficient embryos have anterior somites without gamma-secretase, presenilin may have a gamma-secretase-independent role in somitogenesis. Embryos triple homozygous for both presenilin null alleles and a Notch allele that is a poor substrate for presenilin (N1(V-->G)) experience fortuitous cleavage of N1(V-->G) by another protease. This restores NICD, anterior segmentation, and bilateral symmetry but does not rescue rostral/caudal identities. These data clarify multiple roles for Notch signaling during segmentation and suggest that the earliest stages of somitogenesis are regulated by both Notch-dependent and Notch-independent functions of presenilin.
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MESH Headings
- Amyloid Precursor Protein Secretases
- Animals
- Aspartic Acid Endopeptidases
- Body Patterning/genetics
- Body Patterning/physiology
- Cell Differentiation
- Endopeptidases/metabolism
- In Situ Hybridization
- Membrane Proteins/deficiency
- Membrane Proteins/genetics
- Membrane Proteins/metabolism
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Mice, Mutant Strains
- Microscopy, Electron, Scanning
- Phenotype
- Presenilin-1
- Presenilin-2
- Receptor, Notch1
- Receptor, Notch2
- Receptors, Cell Surface/deficiency
- Receptors, Cell Surface/genetics
- Receptors, Cell Surface/physiology
- Somites/cytology
- Somites/metabolism
- Transcription Factors/deficiency
- Transcription Factors/genetics
- Transcription Factors/physiology
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Affiliation(s)
- Stacey S Huppert
- Department of Molecular Biology and Pharmacology, Division of Dermatology, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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