101
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Moesgaard L, Petersen D, Szomek M, Reinholdt P, Winkler MBL, Frain KM, Müller P, Pedersen BP, Kongsted J, Wüstner D. Mechanistic Insight into Lipid Binding to Yeast Niemann Pick Type C2 Protein. Biochemistry 2020; 59:4407-4420. [PMID: 33141558 DOI: 10.1021/acs.biochem.0c00574] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Niemann Pick type C2 (NPC2) is a small sterol binding protein in the lumen of late endosomes and lysosomes. We showed recently that the yeast homologue of NPC2 together with its binding partner NCR1 mediates integration of ergosterol, the main sterol in yeast, into the vacuolar membrane. Here, we study the binding specificity and the molecular details of lipid binding to yeast NPC2. We find that NPC2 binds fluorescence- and spin-labeled analogues of phosphatidylcholine (PC), phosphatidylserine, phosphatidylinositol (PI), and sphingomyelin. Spectroscopic experiments show that NPC2 binds lipid monomers in solution but can also interact with lipid analogues in membranes. We further identify ergosterol, PC, and PI as endogenous NPC2 ligands. Using molecular dynamics simulations, we show that NPC2's binding pocket can adapt to the ligand shape and closes around bound ergosterol. Hydrophobic interactions stabilize the binding of ergosterol, but binding of phospholipids is additionally stabilized by electrostatic interactions at the mouth of the binding site. Our work identifies key residues that are important in stabilizing the binding of a phospholipid to yeast NPC2, thereby rationalizing future mutagenesis studies. Our results suggest that yeast NPC2 functions as a general "lipid solubilizer" and binds a variety of amphiphilic lipid ligands, possibly to prevent lipid micelle formation inside the vacuole.
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Affiliation(s)
- Laust Moesgaard
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
| | - Daniel Petersen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
| | - Maria Szomek
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
| | - Peter Reinholdt
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
| | - Mikael B L Winkler
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10, Aarhus C 8000, Denmark
| | - Kelly May Frain
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10, Aarhus C 8000, Denmark
| | - Peter Müller
- Department of Biology, Humboldt University Berlin, Unter den Linden 6, 10099 Berlin, Germany
| | - Bjørn Panyella Pedersen
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10, Aarhus C 8000, Denmark
| | - Jacob Kongsted
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
| | - Daniel Wüstner
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
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102
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Baker S, Petukh M. Effect of pH on the Ability of N-Terminal Domain of Human NPC1 to Recognize, Bind, and Transfer Cholesterol. ACS OMEGA 2020; 5:29222-29230. [PMID: 33225153 PMCID: PMC7676335 DOI: 10.1021/acsomega.0c03983] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 10/21/2020] [Indexed: 06/11/2023]
Abstract
Niemann-Pick type C1 (NPC1) is a large multidomain transmembrane protein essential for transporting cholesterol (CLR) from late endosomes and lysosomes to the endoplasmic reticulum and other cellular compartments. The lumen-facing N-terminal domain (NTD), involved in direct binding of CLR, is expected to have an optimum activity at acidic pH = 4.5. Here, we show that acidic pH is vital for the functionality of NPC1(NTD) and should be taken into account when studying the protein activity. We applied evolutionary, structural, and physicochemical analyses to decipher the consequences of a change in pH from acidic (pH = 4.5) to neutral (pH = 7.2) on the structural integrity of the NTD and its ability to bind CLR. We revealed that the change in pH from 4.5 to 7.2 increases the potential energy of the protein in both apo- and holo-states making the system less energetically favorable. At neutral pH, the flexibility of the protein in the apo-state is decreased caused by the alteration of specific interactions, which in turn might have a high impact on ligand recognition and binding. In contrast, neutral pH significantly exaggerates the flexibility of the protein with bound CLR that causes a partial exposure of the ligand to the water phase and its mislocation inside the ligand-binding pocket, which might obstruct CLR translocation through the membrane.
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103
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Luquain-Costaz C, Rabia M, Hullin-Matsuda F, Delton I. Bis(monoacylglycero)phosphate, an important actor in the host endocytic machinery hijacked by SARS-CoV-2 and related viruses. Biochimie 2020; 179:247-256. [PMID: 33159981 PMCID: PMC7642752 DOI: 10.1016/j.biochi.2020.10.018] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 10/28/2020] [Accepted: 10/29/2020] [Indexed: 12/12/2022]
Abstract
Viruses, including the novel coronavirus SARS-CoV-2, redirect infected cell metabolism to their own purposes. After binding to its receptor angiotensin-converting enzyme 2 (ACE2) on the cell surface, the SARS-CoV-2 is taken up by receptor-mediated endocytosis ending in the acidic endolysosomal compartment. The virus hijacks the endosomal machinery leading to fusion of viral and endosomal membranes and release of the viral RNA into the cytosol. This mini-review specifically highlights the membrane lipid organization of the endosomal system focusing on the unconventional and late endosome/lysosome-specific phospholipid, bis(monoacylglycero)phosphate (BMP). BMP is enriched in alveolar macrophages of lung, one of the target tissue of SARS-CoV-2. This review details the BMP structure, its unsaturated fatty acid composition and fusogenic properties that are essential for the highly dynamic formation of the intraluminal vesicles inside the endosomes. Interestingly, BMP is necessary for infection and replication of enveloped RNA virus such as SARS-CoV-1 and Dengue virus. We also emphasize the role of BMP in lipid sorting and degradation, especially cholesterol transport in cooperation with Niemann Pick type C proteins (NPC 1 and 2) and with some oxysterol-binding protein (OSBP)-related proteins (ORPs) as well as in sphingolipid degradation. Interestingly, numerous virus infection required NPC1 as well as ORPs along the endocytic pathway. Furthermore, BMP content is increased during pathological endosomal lipid accumulation in various lysosomal storage disorders. This is particularly important knowing the high percentage of patients with metabolic disorders among the SARS-CoV-2 infected patients presenting severe forms of COVID-19.
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Affiliation(s)
- Céline Luquain-Costaz
- Univ-Lyon, CarMeN Laboratory, Inserm U1060, INRAe U1397, INSA Lyon, Villeurbanne, France
| | - Maxence Rabia
- Univ-Lyon, CarMeN Laboratory, Inserm U1060, INRAe U1397, INSA Lyon, Villeurbanne, France
| | | | - Isabelle Delton
- Univ-Lyon, CarMeN Laboratory, Inserm U1060, INRAe U1397, INSA Lyon, Villeurbanne, France.
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104
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A trimeric Rab7 GEF controls NPC1-dependent lysosomal cholesterol export. Nat Commun 2020; 11:5559. [PMID: 33144569 PMCID: PMC7642327 DOI: 10.1038/s41467-020-19032-0] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Accepted: 09/18/2020] [Indexed: 12/26/2022] Open
Abstract
Cholesterol import in mammalian cells is mediated by the LDL receptor pathway. Here, we perform a genome-wide CRISPR screen using an endogenous cholesterol reporter and identify >100 genes involved in LDL-cholesterol import. We characterise C18orf8 as a core subunit of the mammalian Mon1-Ccz1 guanidine exchange factor (GEF) for Rab7, required for complex stability and function. C18orf8-deficient cells lack Rab7 activation and show severe defects in late endosome morphology and endosomal LDL trafficking, resulting in cellular cholesterol deficiency. Unexpectedly, free cholesterol accumulates within swollen lysosomes, suggesting a critical defect in lysosomal cholesterol export. We find that active Rab7 interacts with the NPC1 cholesterol transporter and licenses lysosomal cholesterol export. This process is abolished in C18orf8-, Ccz1- and Mon1A/B-deficient cells and restored by a constitutively active Rab7. The trimeric Mon1-Ccz1-C18orf8 (MCC) GEF therefore plays a central role in cellular cholesterol homeostasis coordinating Rab7 activation, endosomal LDL trafficking and NPC1-dependent lysosomal cholesterol export. Lysosomes play an important role in cellular LDL-cholesterol uptake. Here, the authors perform a genome-wide genetic screen for cholesterol regulators and identify C18orf8 as a conserved subunit of a trimeric Rab7 GEF that controls LDL trafficking and NPC1-dependent lysosomal cholesterol export.
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105
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Dubey V, Bozorg B, Wüstner D, Khandelia H. Cholesterol binding to the sterol-sensing region of Niemann Pick C1 protein confines dynamics of its N-terminal domain. PLoS Comput Biol 2020; 16:e1007554. [PMID: 33021976 PMCID: PMC7537887 DOI: 10.1371/journal.pcbi.1007554] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Accepted: 07/02/2020] [Indexed: 12/12/2022] Open
Abstract
Lysosomal accumulation of cholesterol is a hallmark of Niemann Pick type C (NPC) disease caused by mutations primarily in the lysosomal membrane protein NPC1. NPC1 contains a transmembrane sterol-sensing domain (SSD), which is supposed to regulate protein activity upon cholesterol binding, but the mechanisms underlying this process are poorly understood. Using atomistic simulations, we show that in the absence of cholesterol in the SSD, the luminal domains of NPC1 are highly dynamic, resulting in the disengagement of the NTD from the rest of the protein. The disengaged NPC1 adopts a flexed conformation that approaches the lipid bilayer, and could represent a conformational state primed to receive a sterol molecule from the soluble lysosomal cholesterol carrier NPC2. The binding of cholesterol to the SSD of NPC1 allosterically suppresses the conformational dynamics of the luminal domains resulting in an upright NTD conformation. The presence of an additional 20% cholesterol in the membrane has negligible impact on this process. The additional presence of an NTD-bound cholesterol suppresses the flexing of the NTD. We propose that cholesterol acts as an allosteric effector, and the modulation of NTD dynamics by the SSD-bound cholesterol constitutes an allosteric feedback mechanism in NPC1 that controls cholesterol abundance in the lysosomal membrane. Cholesterol is absorbed from LDL particles in esterified form, and is broken down to free cholesterol in the lysosomes of cells, from where cholesterol must be transported to other cellular compartments such as the plasma membrane. The Niemann Pick type C (NPC) diseases arise from deficient cholesterol transport and result from mutations in the cholesterol transport protein NPC1. Using computer simulations, we show that cholesterol, when bound to one part of NPC1, can control the structural transitions of an 8-nm distant, different part of NPC1 protein called the N-terminal domain (NTD). Such long-range control of protein conformations (allostery), controls a wide range of cellular functions mediated by proteins. Fundamental molecular insights into the function of the NPC1 protein can potentially lead to better pharmaceutical interventions for the NPC diseases.
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Affiliation(s)
- Vikas Dubey
- PhyLife Physical Life Sciences, Department of Physics Chemistry, and Pharmacy, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark
- Department of Physics Chemistry, and Pharmacy, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark
| | - Behruz Bozorg
- PhyLife Physical Life Sciences, Department of Physics Chemistry, and Pharmacy, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark
- Department of Physics Chemistry, and Pharmacy, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark
| | - Daniel Wüstner
- PhyLife Physical Life Sciences, Department of Physics Chemistry, and Pharmacy, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark
| | - Himanshu Khandelia
- PhyLife Physical Life Sciences, Department of Physics Chemistry, and Pharmacy, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark
- Department of Physics Chemistry, and Pharmacy, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark
- MEMPHYS: Center for Biomembrane Physics, Odense M, Denmark
- * E-mail:
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106
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Yoon HJ, Jeong H, Lee HH, Jang S. Molecular dynamics study with mutation shows that N-terminal domain structural re-orientation in Niemann-Pick type C1 is required for proper alignment of cholesterol transport. J Neurochem 2020; 156:967-978. [PMID: 32880929 PMCID: PMC7461377 DOI: 10.1111/jnc.15150] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 07/30/2020] [Accepted: 07/30/2020] [Indexed: 11/27/2022]
Abstract
The lysosomal membrane protein Niemann‐Pick type C1 (NPC1) and Niemann‐Pick type C2 (NPC2) are main players of cholesterol control in the lysosome and it is known that the mutation on these proteins leads to the cholesterol trafficking‐related neurodegenerative disease, which is called the NPC disease. The mutation R518W or R518Q on the NPC1 is one of the type of disease‐related mutation that causes cholesterol transports to be cut in half, which results in the accumulation of cholesterol and lipids in the late endosomal/lysosomal compartment of the cell. Even though there has been significant progress with understanding the cholesterol transport by NPC1 in combination with NPC2, especially after the structural determination of the full‐length NPC1 in 2016, many details such as the interaction of the full‐length NPC1 with the NPC2, the molecular motions responsible for the cholesterol transport during and after this interaction, and the structure and the function relations of many mutations are still not well understood. In this study, we report the extensive molecular dynamics simulations in order to gain insight into the structure and the dynamics of NPC1 lumenal domain for the cholesterol transport and the disease behind the mutation (R518W). It was found that the mutation induces a structural shift of the N‐terminal domain, toward the loop region in the middle lumenal domain, which is believed to play a central role in the interaction with NPC2 protein, so the interaction with the NPC2 protein might be less favorable compared to the wild NPC1. Also, the simulation indicates the possible re‐orientation of the N‐terminal domain with both the wild and the R518W‐mutated NPC1 after receiving the cholesterol from the NPC2 that align to form an internal tunnel, which is a possible pose for further action in cholesterol trafficking. We believe the current study can provide a better understanding of the cholesterol transport by NPC1 especially the role of NTD of NPC1 in combination with NPC2 interactions.
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Affiliation(s)
- Hye-Jin Yoon
- Department of Chemistry, Seoul National University, Seoul, Republic of Korea
| | - Hyunah Jeong
- Department of Chemistry, Sejong University, Seoul, Republic of Korea
| | - Hyung Ho Lee
- Department of Chemistry, Seoul National University, Seoul, Republic of Korea
| | - Soonmin Jang
- Department of Chemistry, Sejong University, Seoul, Republic of Korea
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107
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Gesto DS, Pereira CMS, Cerqueira NMFS, Sousa SF. An Atomic-Level Perspective of HMG-CoA-Reductase: The Target Enzyme to Treat Hypercholesterolemia. Molecules 2020; 25:molecules25173891. [PMID: 32859023 PMCID: PMC7503714 DOI: 10.3390/molecules25173891] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 08/23/2020] [Accepted: 08/24/2020] [Indexed: 12/19/2022] Open
Abstract
This review provides an updated atomic-level perspective regarding the enzyme 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMG-CoAR), linking the more recent data on this enzyme with a structure/function interpretation. This enzyme catalyzes one of the most important steps in cholesterol biosynthesis and is regarded as one of the most important drug targets in the treatment of hypercholesterolemia. Taking this into consideration, we review in the present article several aspects of this enzyme, including its structure and biochemistry, its catalytic mechanism and different reported and proposed approaches for inhibiting this enzyme, including the commercially available statins or the possibility of using dimerization inhibitors.
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Affiliation(s)
- Diana S. Gesto
- UCIBIO, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal;
| | - Carlos M. S. Pereira
- UCIBIO/REQUIMTE, BioSIM, Departamento de Biomedicina, Faculdade de Medicina da Universidade do Porto, Alameda Prof. Hernâni Monteiro, 4200-319 Porto, Portugal; (C.M.S.P.); (N.M.F.S.C.)
| | - Nuno M. F. S. Cerqueira
- UCIBIO/REQUIMTE, BioSIM, Departamento de Biomedicina, Faculdade de Medicina da Universidade do Porto, Alameda Prof. Hernâni Monteiro, 4200-319 Porto, Portugal; (C.M.S.P.); (N.M.F.S.C.)
| | - Sérgio F. Sousa
- UCIBIO/REQUIMTE, BioSIM, Departamento de Biomedicina, Faculdade de Medicina da Universidade do Porto, Alameda Prof. Hernâni Monteiro, 4200-319 Porto, Portugal; (C.M.S.P.); (N.M.F.S.C.)
- Correspondence:
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108
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Adenovirus Reveals New Pathway for Cholesterol Egress from the Endolysosomal System. Int J Mol Sci 2020; 21:ijms21165808. [PMID: 32823559 PMCID: PMC7460884 DOI: 10.3390/ijms21165808] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 08/11/2020] [Accepted: 08/12/2020] [Indexed: 12/15/2022] Open
Abstract
In addition to providing invaluable insights to the host response to viral infection, adenovirus continues to be an important model system for discovering basic aspects of cell biology. This is especially true for products of early region three (E3), which have provided the foundation for understanding many new mechanisms regulating intracellular trafficking of host cell proteins involved in the host immune response. Cholesterol homeostasis is vital for proper cellular physiology, and disturbances in cholesterol balance are increasingly recognized as important factors in human disease. Despite its central role in numerous aspects of cellular functions, the mechanisms responsible for delivery of dietary cholesterol to the endoplasmic reticulum, where the lipid metabolic and regulatory machinery reside, remain poorly understood. In this review, we describe a novel intracellular pathway for cholesterol trafficking that has been co-opted by an adenovirus E3 gene product. We describe what is known about the molecular regulation of this pathway, how it might benefit viral replication, and its potential involvement in normal cell physiology. Finally, we make a case that adenovirus has co-opted a cellular pathway that may be dysregulated in various human diseases.
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109
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Abe A, Hiraoka M, Matsuzawa F, Aikawa SI, Niimura Y. Esterification of side-chain oxysterols by lysosomal phospholipase A2. Biochim Biophys Acta Mol Cell Biol Lipids 2020; 1865:158787. [PMID: 32777483 DOI: 10.1016/j.bbalip.2020.158787] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 07/15/2020] [Accepted: 08/02/2020] [Indexed: 11/30/2022]
Abstract
Side-chain oxysterols produced from cholesterol either enzymatically or non-enzymatically show various bioactivities. Lecithin-cholesterol acyltransferase (LCAT) esterifies the C3-hydroxyl group of these sterols as well as cholesterol. Lysosomal phospholipase A2 (LPLA2) is related to LCAT but does not catalyze esterification of cholesterol. First, esterification of side-chain oxysterols by LPLA2 was investigated using recombinant mouse LPLA2 and dioleoyl-PC/sulfatide/oxysterol liposomes under acidic conditions. TLC and LC-MS/MS showed that the C3 and C27-hydroxyl groups of 27-hydroxycholesterol could be individually esterified by LPLA2 to form a monoester with the C27-hydroxyl preference. Cholesterol did not inhibit this reaction. Also, LPLA2 esterified other side-chain oxysterols. Their esterifications by mouse serum containing LCAT supported the idea that their esterifications by LPLA2 occur at the C3-hydroxyl group. N-acetylsphingosine (NAS) acting as an acyl acceptor in LPLA2 transacylation inhibited the side-chain oxysterol esterification by LPLA2. This suggests a competition between hydroxycholesterol and NAS on the acyl-LPLA2 intermediate formed during the reaction. Raising cationic amphiphilic drug concentration or ionic strength in the reaction mixture evoked a reduction of the side-chain oxysterol esterification by LPLA2. This indicates that the esterification could progress via an interfacial interaction of LPLA2 with the lipid membrane surface through an electrostatic interaction. The docking model of acyl-LPLA2 intermediate and side-chain oxysterol provided new insight to elucidate the transacylation mechanism of sterols by LPLA2. Finally, exogenous 25-hydroxycholesterol esterification within alveolar macrophages prepared from wild-type mice was significantly higher than that from LPLA2 deficient mice. This suggests that there is an esterification pathway of side-chain oxysterols via LPLA2.
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Affiliation(s)
- Akira Abe
- Department of Molecular Science of Bacteria, Tokyo University of Agriculture, Tokyo, Japan.
| | - Miki Hiraoka
- Department of Ophthalmology, Health Science University of Hokkaido, Sapporo, Japan
| | | | | | - Youichi Niimura
- Department of Molecular Science of Bacteria, Tokyo University of Agriculture, Tokyo, Japan
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110
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Structural Basis of Low-pH-Dependent Lysosomal Cholesterol Egress by NPC1 and NPC2. Cell 2020; 182:98-111.e18. [DOI: 10.1016/j.cell.2020.05.020] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 03/16/2020] [Accepted: 05/11/2020] [Indexed: 01/19/2023]
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111
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van den Boomen DJH, Volkmar N, Lehner PJ. Ubiquitin-mediated regulation of sterol homeostasis. Curr Opin Cell Biol 2020; 65:103-111. [PMID: 32580085 DOI: 10.1016/j.ceb.2020.04.010] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2020] [Revised: 04/03/2020] [Accepted: 04/26/2020] [Indexed: 11/19/2022]
Abstract
Cholesterol is an essential component of mammalian membranes, and its homeostasis is strictly regulated, with imbalances causing atherosclerosis, Niemann Pick disease, and familial hypercholesterolemia. Cellular cholesterol supply is mediated by LDL-cholesterol import and de novo cholesterol biosynthesis, and both pathways are adjusted to cellular demand by the cholesterol-sensitive SREBP2 transcription factor. Cholesterol homeostasis is modulated by a wide variety of metabolic pathways and the ubiquitination machinery, in particular E3 ubiquitin ligases. In this article, we review recent progress in understanding the role of E3 ubiquitin ligases in the metabolic control of cellular sterol homeostasis.
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Affiliation(s)
- Dick J H van den Boomen
- Cambridge Institute of Therapeutic Immunology & Infectious Disease, University of Cambridge, Cambridge, United Kingdom
| | - Norbert Volkmar
- Cambridge Institute of Therapeutic Immunology & Infectious Disease, University of Cambridge, Cambridge, United Kingdom
| | - Paul J Lehner
- Cambridge Institute of Therapeutic Immunology & Infectious Disease, University of Cambridge, Cambridge, United Kingdom.
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112
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Anand PK. Lipids, inflammasomes, metabolism, and disease. Immunol Rev 2020; 297:108-122. [PMID: 32562313 DOI: 10.1111/imr.12891] [Citation(s) in RCA: 63] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 05/19/2020] [Accepted: 05/27/2020] [Indexed: 12/19/2022]
Abstract
Inflammasomes are multi-protein complexes that regulate the cleavage of cysteine protease caspase-1, secretion of inflammatory cytokines, and induction of inflammatory cell death, pyroptosis. Several members of the nod-like receptor family assemble inflammasome in response to specific ligands. An exception to this is the NLRP3 inflammasome which is activated by structurally diverse entities. Recent studies have suggested that NLRP3 might be a sensor of cellular homeostasis, and any perturbation in distinct metabolic pathways results in the activation of this inflammasome. Lipid metabolism is exceedingly important in maintaining cellular homeostasis, and it is recognized that cells and tissues undergo extensive lipid remodeling during activation and disease. Some lipids are involved in instigating chronic inflammatory diseases, and new studies have highlighted critical upstream roles for lipids, particularly cholesterol, in regulating inflammasome activation implying key functions for inflammasomes in diseases with defective lipid metabolism. The focus of this review is to highlight how lipids regulate inflammasome activation and how this leads to the progression of inflammatory diseases. The key roles of cholesterol metabolism in the activation of inflammasomes have been comprehensively discussed. Besides, the roles of oxysterols, fatty acids, phospholipids, and lipid second messengers are also summarized in the context of inflammasomes. The overriding theme is that lipid metabolism has numerous but complex functions in inflammasome activation. A detailed understanding of this area will help us develop therapeutic interventions for diseases where dysregulated lipid metabolism is the underlying cause.
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Affiliation(s)
- Paras K Anand
- Department of Infectious Disease, Faculty of Medicine, Imperial College London, London, UK
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113
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Tousignant KD, Rockstroh A, Poad BLJ, Talebi A, Young RSE, Taherian Fard A, Gupta R, Zang T, Wang C, Lehman ML, Swinnen JV, Blanksby SJ, Nelson CC, Sadowski MC. Therapy-induced lipid uptake and remodeling underpin ferroptosis hypersensitivity in prostate cancer. Cancer Metab 2020; 8:11. [PMID: 32577235 PMCID: PMC7304214 DOI: 10.1186/s40170-020-00217-6] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Accepted: 05/08/2020] [Indexed: 12/13/2022] Open
Abstract
Background Metabolic reprograming, non-mutational epigenetic changes, increased cell plasticity, and multidrug tolerance are early hallmarks of therapy resistance in cancer. In this temporary, therapy-tolerant state, cancer cells are highly sensitive to ferroptosis, a form of regulated cell death that is caused by oxidative stress through excess levels of iron-dependent peroxidation of polyunsaturated fatty acids (PUFA). However, mechanisms underpinning therapy-induced ferroptosis hypersensitivity remain to be elucidated. Methods We used quantitative single-cell imaging of fluorescent metabolic probes, transcriptomics, proteomics, and lipidomics to perform a longitudinal analysis of the adaptive response to androgen receptor-targeted therapies (androgen deprivation and enzalutamide) in prostate cancer (PCa). Results We discovered that cessation of cell proliferation and a robust reduction in bioenergetic processes were associated with multidrug tolerance and a strong accumulation of lipids. The gain in lipid biomass was fueled by enhanced lipid uptake through cargo non-selective (macropinocytosis, tunneling nanotubes) and cargo-selective mechanisms (lipid transporters), whereas de novo lipid synthesis was strongly reduced. Enzalutamide induced extensive lipid remodeling of all major phospholipid classes at the expense of storage lipids, leading to increased desaturation and acyl chain length of membrane lipids. The rise in membrane PUFA levels enhanced membrane fluidity and lipid peroxidation, causing hypersensitivity to glutathione peroxidase (GPX4) inhibition and ferroptosis. Combination treatments against AR and fatty acid desaturation, lipase activities, or growth medium supplementation with antioxidants or PUFAs altered GPX4 dependence. Conclusions Our work provides mechanistic insight into processes of lipid metabolism that underpin the acquisition of therapy-induced GPX4 dependence and ferroptosis hypersensitivity to standard of care therapies in PCa. It demonstrates novel strategies to suppress the therapy-tolerant state that may have potential to delay and combat resistance to androgen receptor-targeted therapies, a currently unmet clinical challenge of advanced PCa. Since enhanced GPX4 dependence is an adaptive phenotype shared by several types of cancer in response to different therapies, our work might have universal implications for our understanding of metabolic events that underpin resistance to cancer therapies.
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Affiliation(s)
- Kaylyn D Tousignant
- Australian Prostate Cancer Research Centre - Queensland, Institute of Health and Biomedical Innovation, School of Biomedical Sciences, Faculty of Health, Queensland University of Technology (QUT), Princess Alexandra Hospital, Translational Research Institute, Brisbane, Australia
| | - Anja Rockstroh
- Australian Prostate Cancer Research Centre - Queensland, Institute of Health and Biomedical Innovation, School of Biomedical Sciences, Faculty of Health, Queensland University of Technology (QUT), Princess Alexandra Hospital, Translational Research Institute, Brisbane, Australia
| | - Berwyck L J Poad
- Central Analytical Research Facility, Institute for Future Environments, Queensland University of Technology, Brisbane, Australia
| | - Ali Talebi
- Department of Oncology, Laboratory of Lipid Metabolism and Cancer, LKI Leuven Cancer Institute, KU Leuven-University of Leuven, Leuven, Belgium
| | - Reuben S E Young
- Central Analytical Research Facility, Institute for Future Environments, Queensland University of Technology, Brisbane, Australia
| | - Atefeh Taherian Fard
- Australian Prostate Cancer Research Centre - Queensland, Institute of Health and Biomedical Innovation, School of Biomedical Sciences, Faculty of Health, Queensland University of Technology (QUT), Princess Alexandra Hospital, Translational Research Institute, Brisbane, Australia
| | - Rajesh Gupta
- Central Analytical Research Facility, Institute for Future Environments, Queensland University of Technology, Brisbane, Australia
| | - Tuo Zang
- Australian Prostate Cancer Research Centre - Queensland, Institute of Health and Biomedical Innovation, School of Biomedical Sciences, Faculty of Health, Queensland University of Technology (QUT), Princess Alexandra Hospital, Translational Research Institute, Brisbane, Australia
| | - Chenwei Wang
- Australian Prostate Cancer Research Centre - Queensland, Institute of Health and Biomedical Innovation, School of Biomedical Sciences, Faculty of Health, Queensland University of Technology (QUT), Princess Alexandra Hospital, Translational Research Institute, Brisbane, Australia
| | - Melanie L Lehman
- Australian Prostate Cancer Research Centre - Queensland, Institute of Health and Biomedical Innovation, School of Biomedical Sciences, Faculty of Health, Queensland University of Technology (QUT), Princess Alexandra Hospital, Translational Research Institute, Brisbane, Australia.,Vancouver Prostate Centre, Department of Urologic Sciences, University of British Columbia, Vancouver, Canada
| | - Johan V Swinnen
- Department of Oncology, Laboratory of Lipid Metabolism and Cancer, LKI Leuven Cancer Institute, KU Leuven-University of Leuven, Leuven, Belgium
| | - Stephen J Blanksby
- Central Analytical Research Facility, Institute for Future Environments, Queensland University of Technology, Brisbane, Australia
| | - Colleen C Nelson
- Australian Prostate Cancer Research Centre - Queensland, Institute of Health and Biomedical Innovation, School of Biomedical Sciences, Faculty of Health, Queensland University of Technology (QUT), Princess Alexandra Hospital, Translational Research Institute, Brisbane, Australia
| | - Martin C Sadowski
- Australian Prostate Cancer Research Centre - Queensland, Institute of Health and Biomedical Innovation, School of Biomedical Sciences, Faculty of Health, Queensland University of Technology (QUT), Princess Alexandra Hospital, Translational Research Institute, Brisbane, Australia.,Cancer & Ageing Research Program, Institute of Health and Biomedical Innovation, School of Biomedical Sciences, Faculty of Health, Queensland University of Technology (QUT), Translational Research Institute, Brisbane, Australia
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114
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Zhang R, Tang BS, Guo JF. Research advances on neurite outgrowth inhibitor B receptor. J Cell Mol Med 2020; 24:7697-7705. [PMID: 32542927 PMCID: PMC7348171 DOI: 10.1111/jcmm.15391] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 04/17/2020] [Accepted: 04/27/2020] [Indexed: 12/24/2022] Open
Abstract
Neurite outgrowth inhibitor‐B (Nogo‐B) is a membrane protein which is extensively expressed in multiple organs, especially in endothelial cells and vascular smooth muscle cells of blood vessels and belongs to the reticulon protein family. Notably, its specific receptor, Nogo‐B receptor (NgBR), encoded by NUS1, has been implicated in many crucial cellular processes, such as cholesterol trafficking, lipid metabolism, dolichol synthesis, protein N‐glycosylation, vascular remodelling, angiogenesis, tumorigenesis and neurodevelopment. In recent years, accumulating studies have demonstrated the statistically significant changes of NgBR expression levels in human diseases, including Niemann‐Pick type C disease, fatty liver, congenital disorders of glycosylation, persistent pulmonary hypertension of the newborn, invasive ductal breast carcinoma, malignant melanoma, non‐small cell lung carcinoma, paediatric epilepsy and Parkinson's disease. Besides, both the in vitro and in vivo studies have shown that NgBR overexpression or knockdown contribute to the alteration of various pathophysiological processes. Thus, there is a broad development potential in therapeutic strategies by modifying the expression levels of NgBR.
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Affiliation(s)
- Rui Zhang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Bei-Sha Tang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China.,Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, China.,National Clinical Research Center for Geriatric Disorders, Central South University, Changsha, China.,Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, China.,Parkinson's Disease Center, Beijing Institute for Brain Disorders, Beijing, China
| | - Ji-Feng Guo
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China.,Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, China.,National Clinical Research Center for Geriatric Disorders, Central South University, Changsha, China.,Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, China
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115
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Saha P, Shumate JL, Caldwell JG, Elghobashi-Meinhardt N, Lu A, Zhang L, Olsson NE, Elias JE, Pfeffer SR. Inter-domain dynamics drive cholesterol transport by NPC1 and NPC1L1 proteins. eLife 2020; 9:e57089. [PMID: 32410728 PMCID: PMC7228765 DOI: 10.7554/elife.57089] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 04/25/2020] [Indexed: 01/17/2023] Open
Abstract
Transport of LDL-derived cholesterol from lysosomes into the cytoplasm requires NPC1 protein; NPC1L1 mediates uptake of dietary cholesterol. We introduced single disulfide bonds into NPC1 and NPC1L1 to explore the importance of inter-domain dynamics in cholesterol transport. Using a sensitive method to monitor lysosomal cholesterol efflux, we found that NPC1's N-terminal domain need not release from the rest of the protein for efficient cholesterol export. Either introducing single disulfide bonds to constrain lumenal/extracellular domains or shortening a cytoplasmic loop abolishes transport activity by both NPC1 and NPC1L1. The widely prescribed cholesterol uptake inhibitor, ezetimibe, blocks NPC1L1; we show that residues that lie at the interface between NPC1L1's three extracellular domains comprise the drug's binding site. These data support a model in which cholesterol passes through the cores of NPC1/NPC1L1 proteins; concerted movement of various domains is needed for transfer and ezetimibe blocks transport by binding to multiple domains simultaneously.
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Affiliation(s)
- Piyali Saha
- Department of Biochemistry, Stanford University School of MedicineStanfordUnited States
| | - Justin L Shumate
- Department of Biochemistry, Stanford University School of MedicineStanfordUnited States
| | - Jenna G Caldwell
- Department of Biochemistry, Stanford University School of MedicineStanfordUnited States
| | | | - Albert Lu
- Department of Biochemistry, Stanford University School of MedicineStanfordUnited States
| | | | - Niclas E Olsson
- Department of Chemical and Systems Biology, Stanford University School of MedicineStanfordUnited States
| | | | - Suzanne R Pfeffer
- Department of Biochemistry, Stanford University School of MedicineStanfordUnited States
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116
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Structure of nevanimibe-bound tetrameric human ACAT1. Nature 2020; 581:339-343. [PMID: 32433613 DOI: 10.1038/s41586-020-2295-8] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2020] [Accepted: 03/17/2020] [Indexed: 11/08/2022]
Abstract
Cholesterol is an essential component of mammalian cell membranes, constituting up to 50% of plasma membrane lipids. By contrast, it accounts for only 5% of lipids in the endoplasmic reticulum (ER)1. The ER enzyme sterol O-acyltransferase 1 (also named acyl-coenzyme A:cholesterol acyltransferase, ACAT1) transfers a long-chain fatty acid to cholesterol to form cholesteryl esters that coalesce into cytosolic lipid droplets. Under conditions of cholesterol overload, ACAT1 maintains the low cholesterol concentration of the ER and thereby has an essential role in cholesterol homeostasis2,3. ACAT1 has also been implicated in Alzheimer's disease4, atherosclerosis5 and cancers6. Here we report a cryo-electron microscopy structure of human ACAT1 in complex with nevanimibe7, an inhibitor that is in clinical trials for the treatment of congenital adrenal hyperplasia. The ACAT1 holoenzyme is a tetramer that consists of two homodimers. Each monomer contains nine transmembrane helices (TMs), six of which (TM4-TM9) form a cavity that accommodates nevanimibe and an endogenous acyl-coenzyme A. This cavity also contains a histidine that has previously been identified as essential for catalytic activity8. Our structural data and biochemical analyses provide a physical model to explain the process of cholesterol esterification, as well as details of the interaction between nevanimibe and ACAT1, which may help to accelerate the development of ACAT1 inhibitors to treat related diseases.
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117
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Meneses-Salas E, García-Melero A, Blanco-Muñoz P, Jose J, Brenner MS, Lu A, Tebar F, Grewal T, Rentero C, Enrich C. Selective Degradation Permits a Feedback Loop Controlling Annexin A6 and Cholesterol Levels in Endolysosomes of NPC1 Mutant Cells. Cells 2020; 9:cells9051152. [PMID: 32392809 PMCID: PMC7291204 DOI: 10.3390/cells9051152] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 04/23/2020] [Accepted: 05/05/2020] [Indexed: 12/22/2022] Open
Abstract
We recently identified elevated annexin A6 (AnxA6) protein levels in Niemann–Pick-type C1 (NPC1) mutant cells. In these cells, AnxA6 depletion rescued the cholesterol accumulation associated with NPC1 deficiency. Here, we demonstrate that elevated AnxA6 protein levels in NPC1 mutants or upon pharmacological NPC1 inhibition, using U18666A, were not due to upregulated AnxA6 mRNA expression, but caused by defects in AnxA6 protein degradation. Two KFERQ-motifs are believed to target AnxA6 to lysosomes for chaperone-mediated autophagy (CMA), and we hypothesized that the cholesterol accumulation in endolysosomes (LE/Lys) triggered by the NPC1 inhibition could interfere with the CMA pathway. Therefore, AnxA6 protein amounts and cholesterol levels in the LE/Lys (LE-Chol) compartment were analyzed in NPC1 mutant cells ectopically expressing lysosome-associated membrane protein 2A (Lamp2A), which is well known to induce the CMA pathway. Strikingly, AnxA6 protein amounts were strongly decreased and coincided with significantly reduced LE-Chol levels in NPC1 mutant cells upon Lamp2A overexpression. Therefore, these findings suggest Lamp2A-mediated restoration of CMA in NPC1 mutant cells to lower LE-Chol levels with concomitant lysosomal AnxA6 degradation. Collectively, we propose CMA to permit a feedback loop between AnxA6 and cholesterol levels in LE/Lys, encompassing a novel mechanism for regulating cholesterol homeostasis in NPC1 disease.
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Affiliation(s)
- Elsa Meneses-Salas
- Departament de Biomedicina, Unitat de Biologia Cel·lular, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, 08036 Barcelona, Spain; (E.M.-S.); (A.G.-M.); (P.B.-M.); (F.T.)
- Centre de Recerca Biomèdica CELLEX, Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), 08036-Barcelona, Spain
| | - Ana García-Melero
- Departament de Biomedicina, Unitat de Biologia Cel·lular, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, 08036 Barcelona, Spain; (E.M.-S.); (A.G.-M.); (P.B.-M.); (F.T.)
- Centre de Recerca Biomèdica CELLEX, Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), 08036-Barcelona, Spain
| | - Patricia Blanco-Muñoz
- Departament de Biomedicina, Unitat de Biologia Cel·lular, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, 08036 Barcelona, Spain; (E.M.-S.); (A.G.-M.); (P.B.-M.); (F.T.)
- Centre de Recerca Biomèdica CELLEX, Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), 08036-Barcelona, Spain
| | - Jaimy Jose
- School of Pharmacy, Faculty of Medicine and Health, University of Sydney, Sydney 2006, NSW, Australia; (J.J.); (M.-S.B.)
| | - Marie-Sophie Brenner
- School of Pharmacy, Faculty of Medicine and Health, University of Sydney, Sydney 2006, NSW, Australia; (J.J.); (M.-S.B.)
| | - Albert Lu
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA 94305, USA;
| | - Francesc Tebar
- Departament de Biomedicina, Unitat de Biologia Cel·lular, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, 08036 Barcelona, Spain; (E.M.-S.); (A.G.-M.); (P.B.-M.); (F.T.)
- Centre de Recerca Biomèdica CELLEX, Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), 08036-Barcelona, Spain
| | - Thomas Grewal
- School of Pharmacy, Faculty of Medicine and Health, University of Sydney, Sydney 2006, NSW, Australia; (J.J.); (M.-S.B.)
- Correspondence: (T.G.); (C.R.); (C.E.); Tel.: +34-934021908 (C.R.)
| | - Carles Rentero
- Departament de Biomedicina, Unitat de Biologia Cel·lular, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, 08036 Barcelona, Spain; (E.M.-S.); (A.G.-M.); (P.B.-M.); (F.T.)
- Centre de Recerca Biomèdica CELLEX, Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), 08036-Barcelona, Spain
- Correspondence: (T.G.); (C.R.); (C.E.); Tel.: +34-934021908 (C.R.)
| | - Carlos Enrich
- Departament de Biomedicina, Unitat de Biologia Cel·lular, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, 08036 Barcelona, Spain; (E.M.-S.); (A.G.-M.); (P.B.-M.); (F.T.)
- Centre de Recerca Biomèdica CELLEX, Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), 08036-Barcelona, Spain
- Correspondence: (T.G.); (C.R.); (C.E.); Tel.: +34-934021908 (C.R.)
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118
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Qi X, Li X. Mechanistic Insights into the Generation and Transduction of Hedgehog Signaling. Trends Biochem Sci 2020; 45:397-410. [PMID: 32311334 PMCID: PMC7174405 DOI: 10.1016/j.tibs.2020.01.006] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 01/19/2020] [Accepted: 01/23/2020] [Indexed: 12/23/2022]
Abstract
Cell differentiation and proliferation require Hedgehog (HH) signaling and aberrant HH signaling causes birth defects or cancers. In this signaling pathway, the N-terminally palmitoylated and C-terminally cholesterylated HH ligand is secreted into the extracellular space with help of the Dispatched-1 (DISP1) and Scube2 proteins. The Patched-1 (PTCH1) protein releases its inhibition of the oncoprotein Smoothened (SMO) after binding the HH ligand, triggering downstream signaling events. In this review, we discuss the recent structural and biochemical studies on four major components of the HH pathway: the HH ligand, DISP1, PTCH1, and SMO. This research provides mechanistic insights into how HH signaling is generated and transduced from the cell surface into the intercellular space and will aid in facilitating the treatment of HH-related diseases.
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Affiliation(s)
- Xiaofeng Qi
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
| | - Xiaochun Li
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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119
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Gutierrez E, Lütjohann D, Kerksiek A, Fabiano M, Oikawa N, Kuerschner L, Thiele C, Walter J. Importance of γ-secretase in the regulation of liver X receptor and cellular lipid metabolism. Life Sci Alliance 2020; 3:3/6/e201900521. [PMID: 32354700 PMCID: PMC7195048 DOI: 10.26508/lsa.201900521] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 04/16/2020] [Accepted: 04/17/2020] [Indexed: 12/12/2022] Open
Abstract
Inhibition of the Alzheimer associated γ-secretase impairs the regulation of cellular lipid droplet homeostasis. Presenilins (PS) are the catalytic components of γ-secretase complexes that mediate intramembrane proteolysis. Mutations in the PS genes are a major cause of familial early-onset Alzheimer disease and affect the cleavage of the amyloid precursor protein, thereby altering the production of the amyloid β-peptide. However, multiple additional protein substrates have been identified, suggesting pleiotropic functions of γ-secretase. Here, we demonstrate that inhibition of γ-secretase causes dysregulation of cellular lipid homeostasis, including up-regulation of liver X receptors, and complex changes in the cellular lipid composition. Genetic and pharmacological inhibition of γsecretase leads to strong accumulation of cytoplasmic lipid droplets, associated with increased levels of acylglycerols, but lowered cholesteryl esters. Furthermore, accumulation of lipid droplets was augmented by increasing levels of amyloid precursor protein C-terminal fragments, indicating a critical involvement of this γ-secretase substrate. Together, these data provide a mechanism that functionally connects γ-secretase activity to cellular lipid metabolism. These effects were also observed in human astrocytic cells, indicating an important function of γ-secretase in cells critical for lipid homeostasis in the brain.
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Affiliation(s)
| | - Dieter Lütjohann
- Institute of Clinical Chemistry and Clinical Pharmacology, University of Bonn, Bonn, Germany
| | - Anja Kerksiek
- Institute of Clinical Chemistry and Clinical Pharmacology, University of Bonn, Bonn, Germany
| | - Marietta Fabiano
- Department of Neurology, University Hospital Bonn, Bonn, Germany
| | - Naoto Oikawa
- Department of Neurology, University Hospital Bonn, Bonn, Germany
| | - Lars Kuerschner
- Life and Medical Sciences Institute, University of Bonn, Bonn, Germany
| | - Christoph Thiele
- Life and Medical Sciences Institute, University of Bonn, Bonn, Germany
| | - Jochen Walter
- Department of Neurology, University Hospital Bonn, Bonn, Germany
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120
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Meng Y, Heybrock S, Neculai D, Saftig P. Cholesterol Handling in Lysosomes and Beyond. Trends Cell Biol 2020; 30:452-466. [PMID: 32413315 DOI: 10.1016/j.tcb.2020.02.007] [Citation(s) in RCA: 90] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2020] [Revised: 02/14/2020] [Accepted: 02/21/2020] [Indexed: 01/06/2023]
Abstract
Lysosomes are of major importance for the regulation of cellular cholesterol homeostasis. Food-derived cholesterol and cholesterol esters contained within lipoproteins are delivered to lysosomes by endocytosis. From the lysosomal lumen, cholesterol is transported to the inner surface of the lysosomal membrane through the glycocalyx; this shuttling requires Niemann-Pick C (NPC) 1 and NPC2 proteins. The lysosomal membrane proteins lysosomal-associated membrane protein (LAMP)-2 and lysosomal integral membrane protein (LIMP)-2/SCARB2 also bind cholesterol. LAMP-2 may serve as a cholesterol reservoir, whereas LIMP-2, like NPC1, is able to transport cholesterol through a transglycocalyx tunnel. Contact sites and fusion events between lysosomes and other organelles mediate the distribution of cholesterol. Lysosomal cholesterol content is sensed thereby regulating mammalian target of rapamycin complex (mTORC)-dependent signaling. This review summarizes our understanding of the major steps in cholesterol handling from the moment it enters the lysosome until it leaves this compartment.
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Affiliation(s)
- Ying Meng
- Department of Cell Biology, School of Basic Medical Sciences, Zhejiang University, Hangzhou, Zhejiang, China
| | - Saskia Heybrock
- Biochemisches Institut, Christian-Albrechts-Universität Kiel, Kiel, Germany
| | - Dante Neculai
- Department of Cell Biology, School of Basic Medical Sciences, Zhejiang University, Hangzhou, Zhejiang, China
| | - Paul Saftig
- Biochemisches Institut, Christian-Albrechts-Universität Kiel, Kiel, Germany.
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121
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Iron chelation by deferiprone does not rescue the Niemann-Pick Disease Type C1 mouse model. Biometals 2020; 33:87-95. [PMID: 32100150 DOI: 10.1007/s10534-020-00233-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2020] [Accepted: 02/19/2020] [Indexed: 02/08/2023]
Abstract
Niemann-Pick Disease Type C (NP-C) is a fatal lysosomal storage disorder with progressive neurodegeneration. In addition to the characteristic cholesterol and lipid overload phenotype, we previously found that altered metal homeostasis is also a pathological feature. Increased brain iron in the Npc1-/- mouse model of NP-C may potentially contribute to neurodegeneration, similar to neurodegenerative diseases such as Alzheimer's and Parkinson's diseases. Deferiprone (DFP) is a brain penetrating iron chelator that has demonstrated effectiveness in preventing neurological deterioration in Parkinson's disease clinical trials. Therefore, we hypothesized that DFP treatment, targeting brain iron overload, may have therapeutic benefits for NP-C. Npc1-/- mice were assigned to four experimental groups: (1) pre-symptomatic (P15) + 75 mg/kg DFP; (2) pre-symptomatic (P15) + 150 mg/kg DFP; (3) symptomatic (P49) + 75 mg/kg DFP; (4) symptomatic (P49) + 150 mg/kg DFP. Our study found that in Npc1-/- mice, DFP treatment did not offer any improvement over the expected disease trajectory and median lifespan. Moreover, earlier treatment and higher dose of DFP resulted in adverse effects on body weight and onset of ataxia. The outcome of our study indicated that, despite increased brain iron, Npc1-/- mice were vulnerable to pharmacological iron depletion, especially in early life. Therefore, based on the current model, iron chelation therapy is not a suitable treatment option for NP-C.
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122
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Gupta A, Rivera-Molina F, Xi Z, Toomre D, Schepartz A. Endosome motility defects revealed at super-resolution in live cells using HIDE probes. Nat Chem Biol 2020; 16:408-414. [PMID: 32094922 PMCID: PMC7176048 DOI: 10.1038/s41589-020-0479-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Accepted: 01/15/2020] [Indexed: 12/13/2022]
Abstract
We report new lipid-based, high-density, environmentally sensitive (HIDE) probes that accurately and selectively image endo-lysosomes and their dynamics at super-resolution for extended times. Treatment of live cells with the small molecules DiIC16TCO or DiIC16’TCO followed by in situ tetrazine ligation reaction with the silicon-rhodamine dye SiR-Tz generates the HIDE probes DiIC16-SiR and DiIC16’-SiR in the endo-lysosomal membrane. These new probes support the acquisition of super-resolution videos of organelle dynamics in primary cells for more than 7 minutes with no detectable change in endosome structure or function. Using DiIC16-SiR and DiIC16’-SiR, we describe the first direct evidence of endosome motility defects in cells from patients with Niemann-Pick Type-C disease. In wild-type fibroblasts, the probes reveal distinct but rare inter-endosome kiss-and-run events that cannot be observed using confocal methods. Our results shed new light on the role of NPC1 in organelle motility and cholesterol trafficking.
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Affiliation(s)
- Aarushi Gupta
- Department of Chemistry, Yale University, New Haven, CT, USA
| | - Felix Rivera-Molina
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA
| | - Zhiqun Xi
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA
| | - Derek Toomre
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA.
| | - Alanna Schepartz
- Department of Chemistry, Yale University, New Haven, CT, USA. .,Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT, USA. .,Department of Chemistry, University of California, Berkeley, CA, USA.
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123
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Abstract
Autophagy is a major intracellular degradation system that derives its degradative abilities from the lysosome. The most well-studied form of autophagy is macroautophagy, which delivers cytoplasmic material to lysosomes via the double-membraned autophagosome. Other forms of autophagy, namely chaperone-mediated autophagy and microautophagy, occur directly on the lysosome. Besides providing the means for degradation, lysosomes are also involved in autophagy regulation and can become substrates of autophagy when damaged. During autophagy, they exhibit notable changes, including increased acidification, enhanced enzymatic activity, and perinuclear localization. Despite their importance to autophagy, details on autophagy-specific regulation of lysosomes remain relatively scarce. This review aims to provide a summary of current understanding on the behaviour of lysosomes during autophagy and outline unexplored areas of autophagy-specific lysosome research.
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Affiliation(s)
- Willa Wen-You Yim
- Department of Biochemistry and Molecular Biology, Graduate School and Faculty of Medicine, The University of Tokyo, Tokyo, 113-0033 Japan
| | - Noboru Mizushima
- Department of Biochemistry and Molecular Biology, Graduate School and Faculty of Medicine, The University of Tokyo, Tokyo, 113-0033 Japan
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124
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Nishimura S, Matsumori N. Chemical diversity and mode of action of natural products targeting lipids in the eukaryotic cell membrane. Nat Prod Rep 2020; 37:677-702. [PMID: 32022056 DOI: 10.1039/c9np00059c] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Covering: up to 2019Nature furnishes bioactive compounds (natural products) with complex chemical structures, yet with simple, sophisticated molecular mechanisms. When natural products exhibit their activities in cells or bodies, they first have to bind or react with a target molecule in/on the cell. The cell membrane is a major target for bioactive compounds. Recently, our understanding of the molecular mechanism of interactions between natural products and membrane lipids progressed with the aid of newly-developed analytical methods. New technology reconnects old compounds with membrane lipids, while new membrane-targeting molecules are being discovered through the screening for antimicrobial potential of natural products. This review article focuses on natural products that bind to eukaryotic membrane lipids, and includes clinically important molecules and key research tools. The chemical diversity of membrane-targeting natural products and the molecular basis of lipid recognition are described. The history of how their mechanism was unveiled, and how these natural products are used in research are also mentioned.
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Affiliation(s)
- Shinichi Nishimura
- Department of Biotechnology, Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, Tokyo 113-8657, Japan.
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125
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Long T, Qi X, Hassan A, Liang Q, De Brabander JK, Li X. Structural basis for itraconazole-mediated NPC1 inhibition. Nat Commun 2020; 11:152. [PMID: 31919352 PMCID: PMC6952396 DOI: 10.1038/s41467-019-13917-5] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Accepted: 12/05/2019] [Indexed: 01/20/2023] Open
Abstract
Niemann-Pick C1 (NPC1), a lysosomal protein of 13 transmembrane helices (TMs) and three lumenal domains, exports low-density-lipoprotein (LDL)-derived cholesterol from lysosomes. TMs 3–7 of NPC1 comprise the Sterol-Sensing Domain (SSD). Previous studies suggest that mutation of the NPC1-SSD or the addition of the anti-fungal drug itraconazole abolishes NPC1 activity in cells. However, the itraconazole binding site and the mechanism of NPC1-mediated cholesterol transport remain unknown. Here, we report a cryo-EM structure of human NPC1 bound to itraconazole, which reveals how this binding site in the center of NPC1 blocks a putative lumenal tunnel linked to the SSD. Functional assays confirm that blocking this tunnel abolishes NPC1-mediated cholesterol egress. Intriguingly, the palmitate anchor of Hedgehog occupies a similar site in the homologous tunnel of Patched, suggesting a conserved mechanism for sterol transport in this family of proteins and establishing a central function of their SSDs. Niemann-Pick C1 (NPC1) exports low-density-lipoprotein (LDL)-derived cholesterol from lysosomes and comporses a Sterol-Sensing Domain (SSD). Here authors report a cryo-EM structure of human NPC1 bound to itraconazole which reveals how this binding site in the center of NPC1 blocks a putative lumenal tunnel linked to the SSD.
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Affiliation(s)
- Tao Long
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Xiaofeng Qi
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Abdirahman Hassan
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Qiren Liang
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Jef K De Brabander
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Xiaochun Li
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA. .,Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA.
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Staying in Healthy Contact: How Peroxisomes Interact with Other Cell Organelles. Trends Mol Med 2019; 26:201-214. [PMID: 31727543 DOI: 10.1016/j.molmed.2019.09.012] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Revised: 08/24/2019] [Accepted: 09/24/2019] [Indexed: 11/24/2022]
Abstract
Peroxisomes share extensive metabolic connections with other cell organelles. Membrane contact sites (MCSs) establish and maintain such interactions, and they are vital for organelle positioning and motility. In the past few years peroxisome interactions and MCSs with other cellular organelles have been explored extensively, resulting in the identification of new MCSs, the tethering molecules involved, and their functional characterization. Defective tethering and compartmental communication can lead to pathological conditions that can be termed 'organelle interaction diseases'. We review peroxisome-organelle interactions in mammals and summarize the most recent knowledge of mammalian peroxisomal organelle contacts in health and disease.
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127
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Corraliza-Gomez M, Sanchez D, Ganfornina MD. Lipid-Binding Proteins in Brain Health and Disease. Front Neurol 2019; 10:1152. [PMID: 31787919 PMCID: PMC6854030 DOI: 10.3389/fneur.2019.01152] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Accepted: 10/14/2019] [Indexed: 12/15/2022] Open
Abstract
A proper lipid management is paramount for a healthy brain. Lipid homeostasis alterations are known to be causative or risk factors for many neurodegenerative diseases, or key elements in the recovery from nervous system injuries of different etiology. In addition to lipid biogenesis and catabolism, non-enzymatic lipid-binding proteins play an important role in brain function and maintenance through aging. Among these types of lipoproteins, apolipoprotein E has received much attention due to the relationship of particular alleles of its gene with the risk and progression of Alzheimer's disease. However, other lipid-binding proteins whose role in lipid homeostasis and control are less known need to be brought to the attention of both researchers and clinicians. The aim of this review is to cover the knowledge of lipid-managing proteins in the brain, with particular attention to new candidates to be relevant for brain function and health.
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Affiliation(s)
- Miriam Corraliza-Gomez
- Departamento de Bioquímica y Biología Molecular y Fisiología, Instituto de Biología y Genética Molecular, Universidad de Valladolid-CSIC, Valladolid, Spain
| | - Diego Sanchez
- Departamento de Bioquímica y Biología Molecular y Fisiología, Instituto de Biología y Genética Molecular, Universidad de Valladolid-CSIC, Valladolid, Spain
| | - Maria D Ganfornina
- Departamento de Bioquímica y Biología Molecular y Fisiología, Instituto de Biología y Genética Molecular, Universidad de Valladolid-CSIC, Valladolid, Spain
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128
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Rana R, Shearer AM, Fletcher EK, Nguyen N, Guha S, Cox DH, Abdelmalek M, Wang Y, Baleja JD, Covic L, Kuliopulos A. PAR2 controls cholesterol homeostasis and lipid metabolism in nonalcoholic fatty liver disease. Mol Metab 2019; 29:99-113. [PMID: 31668396 PMCID: PMC6742970 DOI: 10.1016/j.molmet.2019.08.019] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 08/16/2019] [Accepted: 08/24/2019] [Indexed: 01/04/2023] Open
Abstract
OBJECTIVE Increases in hepatic and plasma cholesterol occur in patients with nonalcoholic fatty liver disease (NAFLD), although the reason for this is not well understood. We investigated whether Protease-Activated Receptor 2 (PAR2) plays a role in cholesterol and lipid homeostasis in NAFLD. METHODS Human liver biopsies (n = 108) were quantified for PAR2 expression from NAFLD cases randomly selected and stratified by liver fibrosis stage, the primary predictor for clinical outcomes, while controlling for age, gender, and BMI between fibrosis groups. Demographic data and laboratory studies on plasma samples were obtained within 6 months of liver biopsy. Wild-type and PAR2-KO (C57BL/6 F2rl1-/-) mice were fed either normal or high fat diet for 16 weeks and plasma and liver assayed for lipids and soluble metabolites. RESULTS Severity of NAFLD and plasma cholesterol levels significantly correlated with hepatocyte PAR2 expression in NAFLD patients. Conversely, PAR2 deficiency in mice resulted in reduced expression of key hepatic genes involved in cholesterol synthesis, a 50% drop in plasma and total liver cholesterol, and induced a reverse cholesterol transport system that culminated in 25% higher fecal bile acid output. PAR2-deficient mice exhibited enhanced fatty acid β-oxidation with a ketogenic shift and an unexpected increase in liver glycogenesis. Mechanistic studies identified Gi-Jnk1/2 as key downstream effectors of protease-activated PAR2 in the regulation of lipid and cholesterol homeostasis in liver. CONCLUSIONS These data indicate that PAR2 may be a new target for the suppression of plasma cholesterol and hepatic fat accumulation in NAFLD and related metabolic conditions.
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Affiliation(s)
- Rajashree Rana
- Center for Hemostasis and Thrombosis Research, Tufts Medical Center, 800 Washington St, Boston, MA, 02111, USA
| | - Andrew M Shearer
- Center for Hemostasis and Thrombosis Research, Tufts Medical Center, 800 Washington St, Boston, MA, 02111, USA; Tufts University School of Graduate Biomedical Sciences, Tufts University School of Medicine, Boston, MA, 02111, USA
| | - Elizabeth K Fletcher
- Center for Hemostasis and Thrombosis Research, Tufts Medical Center, 800 Washington St, Boston, MA, 02111, USA
| | - Nga Nguyen
- Center for Hemostasis and Thrombosis Research, Tufts Medical Center, 800 Washington St, Boston, MA, 02111, USA
| | - Srijoy Guha
- Center for Hemostasis and Thrombosis Research, Tufts Medical Center, 800 Washington St, Boston, MA, 02111, USA
| | - Daniel H Cox
- Tufts University School of Graduate Biomedical Sciences, Tufts University School of Medicine, Boston, MA, 02111, USA
| | - Manal Abdelmalek
- Division of Gastroenterology and Hepatology, Duke University Medical Center, Durham, NC, 27710, USA
| | - Ying Wang
- Division of Gastroenterology and Hepatology, Duke University Medical Center, Durham, NC, 27710, USA
| | - James D Baleja
- Tufts University School of Graduate Biomedical Sciences, Tufts University School of Medicine, Boston, MA, 02111, USA
| | - Lidija Covic
- Center for Hemostasis and Thrombosis Research, Tufts Medical Center, 800 Washington St, Boston, MA, 02111, USA; Tufts University School of Graduate Biomedical Sciences, Tufts University School of Medicine, Boston, MA, 02111, USA
| | - Athan Kuliopulos
- Center for Hemostasis and Thrombosis Research, Tufts Medical Center, 800 Washington St, Boston, MA, 02111, USA; Tufts University School of Graduate Biomedical Sciences, Tufts University School of Medicine, Boston, MA, 02111, USA.
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129
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Liang XD, Zhang YN, Liu CC, Chen J, Chen XN, Sattar Baloch A, Zhou B. U18666A inhibits classical swine fever virus replication through interference with intracellular cholesterol trafficking. Vet Microbiol 2019; 238:108436. [PMID: 31648726 DOI: 10.1016/j.vetmic.2019.108436] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 09/09/2019] [Accepted: 10/01/2019] [Indexed: 12/13/2022]
Abstract
The level of cholesterol in host cells has been demonstrated to affect viral infection. Our previous studies showed that cholesterol-rich membrane rafts mediated the entry of classical swine fever virus (CSFV) into PK-15 or 3D4/21 cells, but the role of cholesterol post entry was still not clear. In this study, we found that CSFV replication before fusion was affected when the cholesterol trafficking in infected cells was disrupted using a cholesterol transport inhibitor, U18666A. Our data showed that U18666A affected both the fusion and replication steps in the life cycle of the virus, but not its binding and entry steps. The subsequent experiments confirmed that niemann-pick C1 (NPC1), a lysosomal membrane protein that helps cholesterol to leave the lysosome, was affected by U18666A, which led to the accumulation of cholesterol in lysosomes and inhibition of CSFV replication. Imipramine, a cationic hydrophobic amine similar to U18666A, also inhibited CSFV replication via similar mechanism. Surprisingly, the antiviral effect of U18666A was restored by the histone deacetylase inhibitor (HDACi), Vorinostat, which suggested that HDACi reverted the dysfunction of NPC1, and intra-cellular cholesterol accumulation disappeared and CSFV replicability resumed. Together, these data indicated that CSFV transformed from early endosome and late endosome into lysosome after endocytosis for further replication and that U18666A was a potential drug candidate for anti-pestivirus treatment.
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Affiliation(s)
- Xiao-Dong Liang
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Yun-Na Zhang
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Chun-Chun Liu
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Jing Chen
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Xiong-Nan Chen
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Abdul Sattar Baloch
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Bin Zhou
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China.
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130
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Winkler MBL, Kidmose RT, Szomek M, Thaysen K, Rawson S, Muench SP, Wüstner D, Pedersen BP. Structural Insight into Eukaryotic Sterol Transport through Niemann-Pick Type C Proteins. Cell 2019; 179:485-497.e18. [PMID: 31543266 DOI: 10.1016/j.cell.2019.08.038] [Citation(s) in RCA: 86] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 07/05/2019] [Accepted: 08/21/2019] [Indexed: 12/24/2022]
Abstract
Niemann-Pick type C (NPC) proteins are essential for sterol homeostasis, believed to drive sterol integration into the lysosomal membrane before redistribution to other cellular membranes. Here, using a combination of crystallography, cryo-electron microscopy, and biochemical and in vivo studies on the Saccharomyces cerevisiae NPC system (NCR1 and NPC2), we present a framework for sterol membrane integration. Sterols are transferred between hydrophobic pockets of vacuolar NPC2 and membrane-protein NCR1. NCR1 has its N-terminal domain (NTD) positioned to deliver a sterol to a tunnel connecting NTD to the luminal membrane leaflet 50 Å away. A sterol is caught inside this tunnel during transport, and a proton-relay network of charged residues in the transmembrane region is linked to this tunnel supporting a proton-driven transport mechanism. We propose a model for sterol integration that clarifies the role of NPC proteins in this essential eukaryotic pathway and that rationalizes mutations in patients with Niemann-Pick disease type C.
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Affiliation(s)
- Mikael B L Winkler
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10, Aarhus C 8000, Denmark
| | - Rune T Kidmose
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10, Aarhus C 8000, Denmark
| | - Maria Szomek
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, Odense M 5230, Denmark
| | - Katja Thaysen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, Odense M 5230, Denmark
| | - Shaun Rawson
- School of Biomedical Sciences and The Astbury Centre for Structural and Molecular Biology, University of Leeds, Leeds LS2 9JT, UK
| | - Stephen P Muench
- School of Biomedical Sciences and The Astbury Centre for Structural and Molecular Biology, University of Leeds, Leeds LS2 9JT, UK
| | - Daniel Wüstner
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, Odense M 5230, Denmark
| | - Bjørn Panyella Pedersen
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10, Aarhus C 8000, Denmark; Aarhus Institute of Advanced Studies, Aarhus University, Høegh-Guldbergs Gade 6B, Aarhus C 8000, Denmark.
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131
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Chiu JE, Thekkiniath J, Mehta S, Müller C, Bracher F, Ben Mamoun C. The yeast pantothenate kinase Cab1 is a master regulator of sterol metabolism and of susceptibility to ergosterol biosynthesis inhibitors. J Biol Chem 2019; 294:14757-14767. [PMID: 31409644 DOI: 10.1074/jbc.ra119.009791] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Revised: 08/12/2019] [Indexed: 12/18/2022] Open
Abstract
In fungi, ergosterol is an essential component of the plasma membrane. Its biosynthesis from acetyl-CoA is the primary target of the most commonly used antifungal drugs. Here, we show that the pantothenate kinase Cab1p, which catalyzes the first step in the metabolism of pantothenic acid for CoA biosynthesis in budding yeast (Saccharomyces cerevisiae), significantly regulates the levels of sterol intermediates and the activities of ergosterol biosynthesis-targeting antifungals. Using genetic and pharmacological analyses, we show that altered pantothenate utilization dramatically alters the susceptibility of yeast cells to ergosterol biosynthesis inhibitors. Genome-wide transcription and MS-based analyses revealed that this regulation is mediated by changes both in the expression of ergosterol biosynthesis genes and in the levels of sterol intermediates. Consistent with these findings, drug interaction experiments indicated that inhibition of pantothenic acid utilization synergizes with the activity of the ergosterol molecule-targeting antifungal amphotericin B and antagonizes that of the ergosterol pathway-targeting antifungal drug terbinafine. Our finding that CoA metabolism controls ergosterol biosynthesis and susceptibility to antifungals could set the stage for the development of new strategies to manage fungal infections and to modulate the potency of current drugs against drug-sensitive and -resistant fungal pathogens.
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Affiliation(s)
- Joy E Chiu
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut 06520
| | - Jose Thekkiniath
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut 06520
| | - Sameet Mehta
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut 06520
| | - Christoph Müller
- Department of Pharmacy-Center for Drug Research, Ludwig-Maximilians-University Munich, Butenandstrasse 5-13, 81377 Munich, Germany
| | - Franz Bracher
- Department of Pharmacy-Center for Drug Research, Ludwig-Maximilians-University Munich, Butenandstrasse 5-13, 81377 Munich, Germany
| | - Choukri Ben Mamoun
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut 06520
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132
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Phosphoinositides in the control of lysosome function and homeostasis. Biochem Soc Trans 2019; 47:1173-1185. [PMID: 31383818 DOI: 10.1042/bst20190158] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Revised: 07/12/2019] [Accepted: 07/15/2019] [Indexed: 12/11/2022]
Abstract
Lysosomes are the main degradative compartments of mammalian cells and serve as platforms for cellular nutrient signaling and sterol transport. The diverse functions of lysosomes and their adaptation to extracellular and intracellular cues are tightly linked to the spatiotemporally controlled synthesis, turnover and interconversion of lysosomal phosphoinositides, minor phospholipids that define membrane identity and couple membrane dynamics to cell signaling. How precisely lysosomal phosphoinositides act and which effector proteins within the lysosome membrane or at the lysosomal surface recognize them is only now beginning to emerge. Importantly, mutations in phosphoinositide metabolizing enzyme cause lysosomal dysfunction and are associated with numerous diseases ranging from neurodegeneration to cancer. Here, we discuss the phosphoinositides and phosphoinositide metabolizing enzymes implicated in lysosome function and homeostasis and outline perspectives for future research.
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133
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Kowatsch C, Woolley RE, Kinnebrew M, Rohatgi R, Siebold C. Structures of vertebrate Patched and Smoothened reveal intimate links between cholesterol and Hedgehog signalling. Curr Opin Struct Biol 2019; 57:204-214. [PMID: 31247512 PMCID: PMC6744280 DOI: 10.1016/j.sbi.2019.05.015] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 05/16/2019] [Accepted: 05/18/2019] [Indexed: 12/21/2022]
Abstract
The Hedgehog (HH) signalling pathway is a cell-cell communication system that controls the patterning of multiple tissues during embryogenesis in metazoans. In adults, HH signals regulate tissue stem cells and regenerative responses. Abnormal signalling can cause birth defects and cancer. The HH signal is received on target cells by Patched (PTCH1), the receptor for HH ligands, and then transmitted across the plasma membrane by Smoothened (SMO). Recent structural and biochemical studies have pointed to a sterol lipid, likely cholesterol itself, as the elusive second messenger that communicates the HH signal between PTCH1 and SMO, thus linking ligand reception to transmembrane signalling.
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Affiliation(s)
- Christiane Kowatsch
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Rachel E Woolley
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Maia Kinnebrew
- Departments of Biochemistry and Medicine, Stanford University School of Medicine, Stanford, CA, United States
| | - Rajat Rohatgi
- Departments of Biochemistry and Medicine, Stanford University School of Medicine, Stanford, CA, United States.
| | - Christian Siebold
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK.
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134
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Inpanathan S, Botelho RJ. The Lysosome Signaling Platform: Adapting With the Times. Front Cell Dev Biol 2019; 7:113. [PMID: 31281815 PMCID: PMC6595708 DOI: 10.3389/fcell.2019.00113] [Citation(s) in RCA: 88] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Accepted: 06/05/2019] [Indexed: 12/12/2022] Open
Abstract
Lysosomes are the terminal degradative compartment of autophagy, endocytosis and phagocytosis. What once was viewed as a simple acidic organelle in charge of macromolecular digestion has emerged as a dynamic organelle capable of integrating cellular signals and producing signal outputs. In this review, we focus on the concept that the lysosome surface serves as a platform to assemble major signaling hubs like mTORC1, AMPK, GSK3 and the inflammasome. These molecular assemblies integrate and facilitate cross-talk between signals such as amino acid and energy levels, membrane damage and infection, and ultimately enable responses such as autophagy, cell growth, membrane repair and microbe clearance. In particular, we review how molecular machinery like the vacuolar-ATPase proton pump, sestrins, the GATOR complexes, and the Ragulator, modulate mTORC1, AMPK, GSK3 and inflammation. We then elaborate how these signals control autophagy initiation and resolution, TFEB-mediated lysosome adaptation, lysosome remodeling, antigen presentation, inflammation, membrane damage repair and clearance. Overall, by being at the cross-roads for several membrane pathways, lysosomes have emerged as the ideal surveillance compartment to sense, integrate and elicit cellular behavior and adaptation in response to changing environmental and cellular conditions.
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Affiliation(s)
- Subothan Inpanathan
- Department of Chemistry and Biology, Graduate Program in Molecular Science, Ryerson University, Toronto, ON, Canada
| | - Roberto J Botelho
- Department of Chemistry and Biology, Graduate Program in Molecular Science, Ryerson University, Toronto, ON, Canada
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135
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Abstract
Signaling pathways that mediate cell-cell communication are essential for collective cell behaviors in multicellular systems. The hedgehog (HH) pathway, first discovered and elucidated in Drosophila, is one of these iconic signaling systems that plays many roles during embryogenesis and in adults; abnormal HH signaling can lead to birth defects and cancer. We review recent structural and biochemical studies that have advanced our understanding of the vertebrate HH pathway, focusing on the mechanisms by which the HH signal is received by patched on target cells, transduced across the cell membrane by smoothened, and transmitted to the nucleus by GLI proteins to influence gene-expression programs.
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Affiliation(s)
- Jennifer H Kong
- Departments of Biochemistry and Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Christian Siebold
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
| | - Rajat Rohatgi
- Departments of Biochemistry and Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
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136
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Affiliation(s)
- Lila M Gierasch
- Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, Massachusetts 01003; Department of Chemistry, University of Massachusetts, Amherst, Massachusetts 01003
| | - F Peter Guengerich
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146
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