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Kumari A, Grønnemose AL, Kristensen KK, Winther AML, Young SG, Jørgensen TJD, Ploug M. Inverse effects of APOC2 and ANGPTL4 on the conformational dynamics of lid-anchoring structures in lipoprotein lipase. Proc Natl Acad Sci U S A 2023; 120:e2221888120. [PMID: 37094117 PMCID: PMC10160976 DOI: 10.1073/pnas.2221888120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Accepted: 03/28/2023] [Indexed: 04/26/2023] Open
Abstract
The lipolytic processing of triglyceride-rich lipoproteins (TRLs) by lipoprotein lipase (LPL) is crucial for the delivery of dietary lipids to the heart, skeletal muscle, and adipose tissue. The processing of TRLs by LPL is regulated in a tissue-specific manner by a complex interplay between activators and inhibitors. Angiopoietin-like protein 4 (ANGPTL4) inhibits LPL by reducing its thermal stability and catalyzing the irreversible unfolding of LPL's α/β-hydrolase domain. We previously mapped the ANGPTL4 binding site on LPL and defined the downstream unfolding events resulting in LPL inactivation. The binding of LPL to glycosylphosphatidylinositol-anchored high-density lipoprotein-binding protein 1 protects against LPL unfolding. The binding site on LPL for an activating cofactor, apolipoprotein C2 (APOC2), and the mechanisms by which APOC2 activates LPL have been unclear and controversial. Using hydrogen-deuterium exchange/mass spectrometry, we now show that APOC2's C-terminal α-helix binds to regions of LPL surrounding the catalytic pocket. Remarkably, APOC2's binding site on LPL overlaps with that for ANGPTL4, but their effects on LPL conformation are distinct. In contrast to ANGPTL4, APOC2 increases the thermal stability of LPL and protects it from unfolding. Also, the regions of LPL that anchor the lid are stabilized by APOC2 but destabilized by ANGPTL4, providing a plausible explanation for why APOC2 is an activator of LPL, while ANGPTL4 is an inhibitor. Our studies provide fresh insights into the molecular mechanisms by which APOC2 binds and stabilizes LPL-and properties that we suspect are relevant to the conformational gating of LPL's active site.
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Affiliation(s)
- Anni Kumari
- Finsen Laboratory, Copenhagen University Hospital-Rigshospitalet, DK-2200Copenhagen N, Denmark
- Finsen Laboratory, Biotech Research and Innovation Centre, University of Copenhagen, DK-2200Copenhagen N, Denmark
| | - Anne Louise Grønnemose
- Finsen Laboratory, Copenhagen University Hospital-Rigshospitalet, DK-2200Copenhagen N, Denmark
- Finsen Laboratory, Biotech Research and Innovation Centre, University of Copenhagen, DK-2200Copenhagen N, Denmark
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, DK–5320Odense, Denmark
| | - Kristian K. Kristensen
- Finsen Laboratory, Copenhagen University Hospital-Rigshospitalet, DK-2200Copenhagen N, Denmark
- Finsen Laboratory, Biotech Research and Innovation Centre, University of Copenhagen, DK-2200Copenhagen N, Denmark
| | - Anne-Marie L. Winther
- Finsen Laboratory, Copenhagen University Hospital-Rigshospitalet, DK-2200Copenhagen N, Denmark
- Finsen Laboratory, Biotech Research and Innovation Centre, University of Copenhagen, DK-2200Copenhagen N, Denmark
| | - Stephen G. Young
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA90095
- Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, CA90095
| | - Thomas J. D. Jørgensen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, DK–5320Odense, Denmark
| | - Michael Ploug
- Finsen Laboratory, Copenhagen University Hospital-Rigshospitalet, DK-2200Copenhagen N, Denmark
- Finsen Laboratory, Biotech Research and Innovation Centre, University of Copenhagen, DK-2200Copenhagen N, Denmark
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Song W, Beigneux AP, Winther AML, Kristensen KK, Grønnemose AL, Yang Y, Tu Y, Munguia P, Morales J, Jung H, de Jong PJ, Jung CJ, Miyashita K, Kimura T, Nakajima K, Murakami M, Birrane G, Jiang H, Tontonoz P, Ploug M, Fong LG, Young SG. Electrostatic sheathing of lipoprotein lipase is essential for its movement across capillary endothelial cells. J Clin Invest 2022; 132:157500. [PMID: 35229724 PMCID: PMC8884915 DOI: 10.1172/jci157500] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 01/19/2022] [Indexed: 12/18/2022] Open
Abstract
GPIHBP1, an endothelial cell (EC) protein, captures lipoprotein lipase (LPL) within the interstitial spaces (where it is secreted by myocytes and adipocytes) and transports it across ECs to its site of action in the capillary lumen. GPIHBP1’s 3-fingered LU domain is required for LPL binding, but the function of its acidic domain (AD) has remained unclear. We created mutant mice lacking the AD and found severe hypertriglyceridemia. As expected, the mutant GPIHBP1 retained the capacity to bind LPL. Unexpectedly, however, most of the GPIHBP1 and LPL in the mutant mice was located on the abluminal surface of ECs (explaining the hypertriglyceridemia). The GPIHBP1-bound LPL was trapped on the abluminal surface of ECs by electrostatic interactions between the large basic patch on the surface of LPL and negatively charged heparan sulfate proteoglycans (HSPGs) on the surface of ECs. GPIHBP1 trafficking across ECs in the mutant mice was normalized by disrupting LPL-HSPG electrostatic interactions with either heparin or an AD peptide. Thus, GPIHBP1’s AD plays a crucial function in plasma triglyceride metabolism; it sheathes LPL’s basic patch on the abluminal surface of ECs, thereby preventing LPL-HSPG interactions and freeing GPIHBP1-LPL complexes to move across ECs to the capillary lumen.
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Affiliation(s)
- Wenxin Song
- Department of Medicine, David Geffen School of Medicine, UCLA, Los Angeles, California, USA
| | - Anne P Beigneux
- Department of Medicine, David Geffen School of Medicine, UCLA, Los Angeles, California, USA
| | - Anne-Marie L Winther
- Finsen Laboratory, Rigshospitalet, Copenhagen, Denmark.,Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Copenhagen, Denmark
| | - Kristian K Kristensen
- Finsen Laboratory, Rigshospitalet, Copenhagen, Denmark.,Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Copenhagen, Denmark
| | - Anne L Grønnemose
- Finsen Laboratory, Rigshospitalet, Copenhagen, Denmark.,Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Copenhagen, Denmark
| | - Ye Yang
- Department of Medicine, David Geffen School of Medicine, UCLA, Los Angeles, California, USA
| | - Yiping Tu
- Department of Medicine, David Geffen School of Medicine, UCLA, Los Angeles, California, USA
| | - Priscilla Munguia
- Department of Medicine, David Geffen School of Medicine, UCLA, Los Angeles, California, USA
| | - Jazmin Morales
- Department of Medicine, David Geffen School of Medicine, UCLA, Los Angeles, California, USA
| | - Hyesoo Jung
- Department of Medicine, David Geffen School of Medicine, UCLA, Los Angeles, California, USA
| | - Pieter J de Jong
- Children's Hospital Oakland Research Institute, Oakland, California, USA
| | - Cris J Jung
- Children's Hospital Oakland Research Institute, Oakland, California, USA
| | - Kazuya Miyashita
- Department of Clinical Laboratory Medicine, Gunma University, Graduate School of Medicine, Maebashi, Gunma, Japan.,Immuno-Biological Laboratories (IBL), Fujioka, Gunma, Japan
| | - Takao Kimura
- Department of Clinical Laboratory Medicine, Gunma University, Graduate School of Medicine, Maebashi, Gunma, Japan
| | - Katsuyuki Nakajima
- Department of Clinical Laboratory Medicine, Gunma University, Graduate School of Medicine, Maebashi, Gunma, Japan
| | - Masami Murakami
- Department of Clinical Laboratory Medicine, Gunma University, Graduate School of Medicine, Maebashi, Gunma, Japan
| | - Gabriel Birrane
- Division of Experimental Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| | - Haibo Jiang
- Department of Chemistry, The University of Hong Kong, Hong Kong
| | - Peter Tontonoz
- Department of Pathology and Laboratory Medicine, UCLA, Los Angeles, California, USA
| | - Michael Ploug
- Finsen Laboratory, Rigshospitalet, Copenhagen, Denmark.,Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Copenhagen, Denmark
| | - Loren G Fong
- Department of Medicine, David Geffen School of Medicine, UCLA, Los Angeles, California, USA
| | - Stephen G Young
- Department of Medicine, David Geffen School of Medicine, UCLA, Los Angeles, California, USA.,Department of Human Genetics, David Geffen School of Medicine, UCLA, Los Angeles, California, USA
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Kjellerup L, Winther AML, Wilson D, Fuglsang AT. Cyclic AMP Pathway Activation and Extracellular Zinc Induce Rapid Intracellular Zinc Mobilization in Candida albicans. Front Microbiol 2018; 9:502. [PMID: 29619016 PMCID: PMC5871664 DOI: 10.3389/fmicb.2018.00502] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Accepted: 03/05/2018] [Indexed: 11/15/2022] Open
Abstract
Zinc is an essential micronutrient, required for a range of zinc-dependent enzymes and transcription factors. In mammalian cells, zinc serves as a second messenger molecule. However, a role for zinc in signaling has not yet been established in the fungal kingdom. Here, we used the intracellular zinc reporter, zinbo-5, which allowed visualization of zinc in the endoplasmic reticulum and other components of the internal membrane system in Candida albicans. We provide evidence for a link between cyclic AMP/PKA- and zinc-signaling in this major human fungal pathogen. Glucose stimulation, which triggers a cyclic AMP spike in this fungus resulted in rapid intracellular zinc mobilization and this “zinc flux” could be stimulated with phosphodiesterase inhibitors and blocked via inhibition of adenylate cyclase or PKA. A similar mobilization of intracellular zinc was generated by stimulation of cells with extracellular zinc and this effect could be reversed with the chelator EDTA. However, zinc-induced zinc flux was found to be cyclic AMP independent. In summary, we show that activation of the cyclic AMP/PKA pathway triggers intracellular zinc mobilization in a fungus. To our knowledge, this is the first described link between cyclic AMP signaling and zinc homeostasis in a human fungal pathogen.
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Affiliation(s)
- Lasse Kjellerup
- Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark.,Pcovery ApS, Copenhagen, Denmark
| | | | - Duncan Wilson
- Medical Research Council Centre for Medical Mycology, University of Aberdeen, Aberdeen Fungal Group, Aberdeen, United Kingdom
| | - Anja T Fuglsang
- Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark
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Bublitz M, Kjellerup L, Cohrt KO, Gordon S, Mortensen AL, Clausen JD, Pallin TD, Hansen JB, Fuglsang AT, Dalby-Brown W, Winther AML. Tetrahydrocarbazoles are a novel class of potent P-type ATPase inhibitors with antifungal activity. PLoS One 2018; 13:e0188620. [PMID: 29293507 PMCID: PMC5749684 DOI: 10.1371/journal.pone.0188620] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Accepted: 11/10/2017] [Indexed: 11/19/2022] Open
Abstract
We have identified a series of tetrahydrocarbazoles as novel P-type ATPase inhibitors. Using a set of rationally designed analogues, we have analyzed their structure-activity relationship using functional assays, crystallographic data and computational modeling. We found that tetrahydrocarbazoles inhibit adenosine triphosphate (ATP) hydrolysis of the fungal H+-ATPase, depolarize the fungal plasma membrane and exhibit broad-spectrum antifungal activity. Comparative inhibition studies indicate that many tetrahydrocarbazoles also inhibit the mammalian Ca2+-ATPase (SERCA) and Na+,K+-ATPase with an even higher potency than Pma1. We have located the binding site for this compound class by crystallographic structure determination of a SERCA-tetrahydrocarbazole complex to 3.0 Å resolution, finding that the compound binds to a region above the ion inlet channel of the ATPase. A homology model of the Candida albicans H+-ATPase based on this crystal structure, indicates that the compounds could bind to the same pocket and identifies pocket extensions that could be exploited for selectivity enhancement. The results of this study will aid further optimization towards selective H+-ATPase inhibitors as a new class of antifungal agents.
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Affiliation(s)
- Maike Bublitz
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
| | - Lasse Kjellerup
- Pcovery, Copenhagen N, Denmark
- Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark
| | | | | | | | | | | | | | - Anja Thoe Fuglsang
- Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark
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Clausen JD, Kjellerup L, Cohrt KO, Hansen JB, Dalby-Brown W, Winther AML. Elucidation of antimicrobial activity and mechanism of action by N-substituted carbazole derivatives. Bioorg Med Chem Lett 2017; 27:4564-4570. [PMID: 28893470 PMCID: PMC5609566 DOI: 10.1016/j.bmcl.2017.08.067] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Revised: 08/20/2017] [Accepted: 08/25/2017] [Indexed: 11/15/2022]
Abstract
Compounds belonging to a carbazole series have been identified as potent fungal plasma membrane proton adenosine triphophatase (H+-ATPase) inhibitors with a broad spectrum of antifungal activity. The carbazole compounds inhibit the adenosine triphosphate (ATP) hydrolysis activity of the essential fungal H+-ATPase, thereby functionally inhibiting the extrusion of protons and extracellular acidification, processes that are responsible for maintaining high plasma membrane potential. The compound class binds to and inhibits the H+-ATPase within minutes, leading to fungal death after 1-3h of compound exposure in vitro. The tested compounds are not selective for the fungal H+-ATPase, exhibiting an overlap of inhibitory activity with the mammalian protein family of P-type ATPases; the sarco(endo)plasmic reticulum calcium ATPase (Ca2+-ATPase) and the sodium potassium ATPase (Na+,K+-ATPase). The ion transport in the P-type ATPases is energized by the conversion of ATP to adenosine diphosphate (ADP) and phosphate and a general inhibitory mechanism mediated by the carbazole derivative could therefore be blocking of the active site. However, biochemical studies show that increased concentrations of ATP do not change the inhibitory activity of the carbazoles suggesting they act as allosteric inhibitors. Furthermore decreased levels of intracellular ATP would suggest that the compounds inhibit the H+-ATPase indirectly, but Candida albicans cells exposed to potent H+-ATPase-inhibitory carbazoles result in increased levels of intracellular ATP, indicating direct inhibition of H+-ATPase.
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Affiliation(s)
| | - Lasse Kjellerup
- Pcovery ApS, Ole Maaløes Vej 3, 2200 Copenhagen N, Denmark; Department of Plant and Environmental Sciences, University of Copenhagen, DK-1871 Frederiksberg, Denmark
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Winther AML, Bublitz M, Karlsen JL, Møller JV, Hansen JB, Nissen P, Buch-Pedersen MJ. The sarcolipin-bound calcium pump stabilizes calcium sites exposed to the cytoplasm. Nature 2013; 495:265-9. [DOI: 10.1038/nature11900] [Citation(s) in RCA: 172] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2012] [Accepted: 01/11/2013] [Indexed: 11/09/2022]
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Winther AML, Liu H, Sonntag Y, Olesen C, le Maire M, Soehoel H, Olsen CE, Christensen SB, Nissen P, Møller JV. Critical roles of hydrophobicity and orientation of side chains for inactivation of sarcoplasmic reticulum Ca2+-ATPase with thapsigargin and thapsigargin analogs. J Biol Chem 2010; 285:28883-92. [PMID: 20551329 DOI: 10.1074/jbc.m110.136242] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Thapsigargin (Tg), a specific inhibitor of sarco/endoplasmic Ca(2+)-ATPases (SERCA), binds with high affinity to the E2 conformation of these ATPases. SERCA inhibition leads to elevated calcium levels in the cytoplasm, which in turn induces apoptosis. We present x-ray crystallographic and intrinsic fluorescence data to show how Tg and chemical analogs of the compound with modified or removed side chains bind to isolated SERCA 1a membranes. This occurs by uptake via the membrane lipid followed by insertion into a resident intramembranous binding site with few adaptative changes. Our binding data indicate that a balanced hydrophobicity and accurate positioning of the side chains, provided by the central guaianolide ring structure, defines a pharmacophore of Tg that governs both high affinity and access to the protein-binding site. Tg analogs substituted with long linkers at O-8 extend from the binding site between transmembrane segments to the putative N-terminal Ca(2+) entry pathway. The long chain analogs provide a rational basis for the localization of the linker, the presence of which is necessary for enabling prostate-specific antigen to cleave peptide-conjugated prodrugs targeting SERCA of cancer cells (Denmeade, S. R., Jakobsen, C. M., Janssen, S., Khan, S. R., Garrett, E. S., Lilja, H., Christensen, S. B., and Isaacs, J. T. (2003) J. Natl. Cancer Inst. 95, 990-1000). Our study demonstrates the usefulness of a simple in vitro system to test and direct development toward the formulation of new Tg derivatives with improved properties for SERCA targeting. Finally, we propose that the Tg binding pocket may be a regulatory site that, for example, is sensitive to cholesterol.
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Affiliation(s)
- Anne-Marie L Winther
- Centre for Membrane Pumps in Cells and Disease-PUMPKIN, Danish National Research Foundation, Denmark
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