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Niemelä A, Koivuniemi A. Systematic evaluation of lecithin:cholesterol acyltransferase binding sites in apolipoproteins via peptide based nanodiscs: regulatory role of charged residues at positions 4 and 7. PLoS Comput Biol 2024; 20:e1012137. [PMID: 38805510 PMCID: PMC11161081 DOI: 10.1371/journal.pcbi.1012137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 06/07/2024] [Accepted: 05/05/2024] [Indexed: 05/30/2024] Open
Abstract
Lecithin:cholesterol acyltransferase (LCAT) exhibits α-activity on high-density and β-activity on low-density lipoproteins. However, the molecular determinants governing LCAT activation by different apolipoproteins remain elusive. Uncovering these determinants would offer the opportunity to design and explore advanced therapies against dyslipidemias. Here, we have conducted coarse-grained and all-atom molecular dynamics simulations of LCAT with nanodiscs made with α-helical amphiphilic peptides either derived from apolipoproteins A1 and E (apoA1 and apoE) or apoA1 mimetic peptide 22A that was optimized to activate LCAT. This study aims to explore what drives the binding of peptides to our previously identified interaction site in LCAT. We hypothesized that this approach could be used to screen for binding sites of LCAT in different apolipoproteins and would provide insights to differently localized LCAT activities. Our screening approach was able to discriminate apoA1 helixes 4, 6, and 7 as key contributors to the interaction with LCAT supporting the previous research data. The simulations provided detailed molecular determinants driving the interaction with LCAT: the formation of hydrogen bonds or salt bridges between peptides E4 or D4 and LCAT S236 or K238 residues. Additionally, salt bridging between R7 and D73 was observed, depending on the availability of R7. Expanding our investigation to diverse plasma proteins, we detected novel LCAT binding helixes in apoL1, apoB100, and serum amyloid A. Our findings suggest that the same binding determinants, involving E4 or D4 -S236 and R7-D73 interactions, influence LCAT β-activity on low-density lipoproteins, where apoE and or apoB100 are hypothesized to interact with LCAT.
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Affiliation(s)
- Akseli Niemelä
- Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki, Helsinki, Finland
| | - Artturi Koivuniemi
- Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki, Helsinki, Finland
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2
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Ciro Acosta S, Díaz-Ordóñez L, Gutierrez-Medina JD, Silva-Cuero YK, Arango-Vélez LG, García-Trujillo AO, Pachajoa H. Familial LCAT Deficiency and Low HDL-C Levels: In silico Characterization of Two Rare LCAT Missense Mutations. Appl Clin Genet 2024; 17:23-32. [PMID: 38404612 PMCID: PMC10893891 DOI: 10.2147/tacg.s438135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Accepted: 12/16/2023] [Indexed: 02/27/2024] Open
Abstract
Mutations in the lecithin-cholesterol acyltransferase (LCAT) gene, which catalyzes the esterification of cholesterol, result in two types of autosomal recessive disorders: Familial LCAT deficiency (FLD) and Fish Eye Disease (FED). While both phenotypes are characterized by corneal opacities and different forms of dyslipidemia, such as low levels of high-density lipoprotein-cholesterol (HDL-C), FLD exhibits more severe clinical manifestations like splenomegaly, anemia, and renal failure. We describe the first clinically and genetically confirmed case of FLD in Colombia which corresponds to a 46-year-old woman with corneal opacity, hypothyroidism, and dyslipidemia, who does not have any manifestations of renal failure, with two pathogenic heterozygous missense variants in the LCAT gene: LCAT (NM_000229.2):c.803G>A (p.Arg268His) and LCAT (NM_000229.2):c.368G>C (p.Arg123Pro). In silico analysis of the mutations predicted the physicochemical properties of the mutated protein, causing instability and potentially decreased LCAT function. These compound mutations highlight the clinical heterogeneity of the phenotypes associated with LCAT gene mutations.
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Affiliation(s)
- Sebastian Ciro Acosta
- Centro de Investigaciones en Anomalias Congenitas y Enfermedades Raras (CIACER), Universidad Icesi, Cali, Colombia
| | - Lorena Díaz-Ordóñez
- Centro de Investigaciones en Anomalias Congenitas y Enfermedades Raras (CIACER), Universidad Icesi, Cali, Colombia
- Departamento de Ciencias Basicas Medicas, Facultad de Salud, Universidad Icesi, Cali, Colombia
| | - Juan David Gutierrez-Medina
- Centro de Investigaciones en Anomalias Congenitas y Enfermedades Raras (CIACER), Universidad Icesi, Cali, Colombia
- Centro de Investigaciones Clinicas, Fundacion Valle del Lili, Cali, Colombia
| | - Yisther Katherine Silva-Cuero
- Centro de Investigaciones en Anomalias Congenitas y Enfermedades Raras (CIACER), Universidad Icesi, Cali, Colombia
- Departamento de Ciencias Basicas Medicas, Facultad de Salud, Universidad Icesi, Cali, Colombia
| | - Luis Guillermo Arango-Vélez
- Servicio de Endocrinologia, Fundacion Valle del Lili, Cali, Colombia
- Departamento de Medicina interna, Seccion de Endocrinologia, Universidad Icesi, Cali, Colombia
| | - Andrés Octavio García-Trujillo
- Servicio de Endocrinologia, Fundacion Valle del Lili, Cali, Colombia
- Departamento de Medicina interna, Seccion de Endocrinologia, Universidad Icesi, Cali, Colombia
| | - Harry Pachajoa
- Centro de Investigaciones en Anomalias Congenitas y Enfermedades Raras (CIACER), Universidad Icesi, Cali, Colombia
- Departamento de Ciencias Basicas Medicas, Facultad de Salud, Universidad Icesi, Cali, Colombia
- Genetic Division, Fundacion Valle del Lili, Cali, Colombia
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3
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Sacher S, Mukherjee A, Ray A. Deciphering structural aspects of reverse cholesterol transport: mapping the knowns and unknowns. Biol Rev Camb Philos Soc 2023; 98:1160-1183. [PMID: 36880422 DOI: 10.1111/brv.12948] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 02/03/2023] [Accepted: 02/24/2023] [Indexed: 03/08/2023]
Abstract
Atherosclerosis is a major contributor to the onset and progression of cardiovascular disease (CVD). Cholesterol-loaded foam cells play a pivotal role in forming atherosclerotic plaques. Induction of cholesterol efflux from these cells may be a promising approach in treating CVD. The reverse cholesterol transport (RCT) pathway delivers cholesteryl ester (CE) packaged in high-density lipoproteins (HDL) from non-hepatic cells to the liver, thereby minimising cholesterol load of peripheral cells. RCT takes place via a well-organised interplay amongst apolipoprotein A1 (ApoA1), lecithin cholesterol acyltransferase (LCAT), ATP binding cassette transporter A1 (ABCA1), scavenger receptor-B1 (SR-B1), and the amount of free cholesterol. Unfortunately, modulation of RCT for treating atherosclerosis has failed in clinical trials owing to our lack of understanding of the relationship between HDL function and RCT. The fate of non-hepatic CEs in HDL is dependent on their access to proteins involved in remodelling and can be regulated at the structural level. An inadequate understanding of this inhibits the design of rational strategies for therapeutic interventions. Herein we extensively review the structure-function relationships that are essential for RCT. We also focus on genetic mutations that disturb the structural stability of proteins involved in RCT, rendering them partially or completely non-functional. Further studies are necessary for understanding the structural aspects of RCT pathway completely, and this review highlights alternative theories and unanswered questions.
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Affiliation(s)
- Sukriti Sacher
- Department of Computational Biology, Indraprastha Institute of Information Technology, Okhla Phase III, New Delhi, 110019, India
| | - Abhishek Mukherjee
- Dhiti Life Sciences Pvt Ltd, B-107, Okhla Phase I, New Delhi, 110020, India
| | - Arjun Ray
- Department of Computational Biology, Indraprastha Institute of Information Technology, Okhla Phase III, New Delhi, 110019, India
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4
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Giorgi L, Niemelä A, Kumpula EP, Natri O, Parkkila P, Huiskonen JT, Koivuniemi A. Mechanistic Insights into the Activation of Lecithin–Cholesterol Acyltransferase in Therapeutic Nanodiscs Composed of Apolipoprotein A-I Mimetic Peptides and Phospholipids. Mol Pharm 2022; 19:4135-4148. [DOI: 10.1021/acs.molpharmaceut.2c00540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Laura Giorgi
- Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki, Helsinki 00014, Finland
| | - Akseli Niemelä
- Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki, Helsinki 00014, Finland
| | - Esa-Pekka Kumpula
- Institute of Biotechnology, Helsinki Institute of Life Science (HiLIFE), University of Helsinki, Helsinki 00014, Finland
| | - Ossi Natri
- Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki, Helsinki 00014, Finland
| | - Petteri Parkkila
- Division of Pharmaceutical Chemistry and Technology, Faculty of Pharmacy, University of Helsinki, Helsinki 00014, Finland
- Division of Nano and Biophysics, Department of Physics, Chalmers University of Technology, Goteborg 412 96, Sweden
| | - Juha T. Huiskonen
- Institute of Biotechnology, Helsinki Institute of Life Science (HiLIFE), University of Helsinki, Helsinki 00014, Finland
| | - Artturi Koivuniemi
- Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki, Helsinki 00014, Finland
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Kotlyarov S. High-Density Lipoproteins: A Role in Inflammation in COPD. Int J Mol Sci 2022; 23:ijms23158128. [PMID: 35897703 PMCID: PMC9331387 DOI: 10.3390/ijms23158128] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 07/19/2022] [Accepted: 07/21/2022] [Indexed: 02/04/2023] Open
Abstract
Chronic obstructive pulmonary disease (COPD) is a widespread disease associated with high rates of disability and mortality. COPD is characterized by chronic inflammation in the bronchi as well as systemic inflammation, which contributes significantly to the clinically heterogeneous course of the disease. Lipid metabolism disorders are common in COPD, being a part of its pathogenesis. High-density lipoproteins (HDLs) are not only involved in lipid metabolism, but are also part of the organism’s immune and antioxidant defense. In addition, HDL is a versatile transport system for endogenous regulatory agents and is also involved in the removal of exogenous substances such as lipopolysaccharide. These functions, as well as information about lipoprotein metabolism disorders in COPD, allow a broader assessment of their role in the pathogenesis of heterogeneous and comorbid course of the disease.
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Affiliation(s)
- Stanislav Kotlyarov
- Department of Nursing, Ryazan State Medical University, 390026 Ryazan, Russia
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6
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Positive allosteric modulators of lecithin: Cholesterol acyltransferase adjust the orientation of the membrane-binding domain and alter its spatial free energy profile. PLoS Comput Biol 2021; 17:e1008426. [PMID: 33720934 PMCID: PMC7993845 DOI: 10.1371/journal.pcbi.1008426] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 03/25/2021] [Accepted: 02/27/2021] [Indexed: 11/29/2022] Open
Abstract
Lecithin:cholesterol acyltransferase protein (LCAT) promotes the esterification reaction between cholesterol and phospholipid-derived acyl chains. Positive allosteric modulators have been developed to treat LCAT deficiencies and, plausibly, also cardiovascular diseases in the future. The mechanism of action of these compounds is poorly understood. Here computational docking and atomistic molecular dynamics simulations were utilized to study the interactions between LCAT and the activating compounds. Results indicate that all drugs bind to the allosteric binding pocket in the membrane-binding domain in a similar fashion. The presence of the compounds in the allosteric site results in a distinct spatial orientation and sampling of the membrane-binding domain (MBD). The MBD’s different spatial arrangement plausibly affects the lid’s movement from closed to open state and vice versa, as suggested by steered molecular dynamics simulations. High-density lipoprotein (HDL) particles play a crucial role in reverse cholesterol transport, whose efficiency is linked to the development of coronary heart disease (CHD), a global health threat showing an increased prevalence in industrial as well as in developing countries. While many drugs for treating CHD exist, e.g., the cholesterol-lowering statins, a substantial residual vascular risk remains, thus calling for novel therapeutic interventions. One of these approaches is to elevate the activity of lecithin:cholesterol acyltransferase (LCAT) enzyme by, e.g., positive allosteric modulators. However, although modulators’ allosteric binding site is known, it is not understood how these compounds can promote the activity LCAT. Therefore, in this article, we aimed to clarify how a set of positive allosteric modulators affect the structural and dynamical properties of LCAT utilizing atomistic molecular dynamics simulations and free energy calculations. Shortly, our findings suggest that the reorientation and the different energetic landscape of the MBD induced by the allosteric compounds may facilitate the lid’s opening, therefore providing a plausible explanation of why the set of positive allosteric modulators promote the activity of LCAT. Besides, this finding is also insightful when deciphering how apoA-I, the principal LCAT activating apolipoprotein in HDL particles, facilitates the activation of LCAT.
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7
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Laurenzi T, Parravicini C, Palazzolo L, Guerrini U, Gianazza E, Calabresi L, Eberini I. rHDL modeling and the anchoring mechanism of LCAT activation. J Lipid Res 2020; 62:100006. [PMID: 33518511 PMCID: PMC7859856 DOI: 10.1194/jlr.ra120000843] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 11/23/2020] [Accepted: 12/02/2020] [Indexed: 11/29/2022] Open
Abstract
Lecithin:cholesterol-acyl transferase (LCAT) plays a major role in cholesterol metabolism as it is the only extracellular enzyme able to esterify cholesterol. LCAT activity is required for lipoprotein remodeling and, most specifically, for the growth and maturation of HDLs. In fact, genetic alterations affecting LCAT functionality may cause a severe reduction in plasma levels of HDL-cholesterol with important clinical consequences. Although several hypotheses were formulated, the exact molecular recognition mechanism between LCAT and HDLs is still unknown. We employed a combination of structural bioinformatics procedures to deepen the insights into the HDL-LCAT interplay that promotes LCAT activation and cholesterol esterification. We have generated a data-driven model of reconstituted HDL (rHDL) and studied the dynamics of an assembled rHDL::LCAT supramolecular complex, pinpointing the conformational changes originating from the interaction between LCAT and apolipoprotein A-I (apoA-I) that are necessary for LCAT activation. Specifically, we propose a mechanism in which the anchoring of LCAT lid to apoA-I helices allows the formation of a hydrophobic hood that expands the LCAT active site and shields it from the solvent, allowing the enzyme to process large hydrophobic substrates.
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Affiliation(s)
- Tommaso Laurenzi
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy
| | - Chiara Parravicini
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy
| | - Luca Palazzolo
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy
| | - Uliano Guerrini
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy
| | - Elisabetta Gianazza
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy
| | - Laura Calabresi
- Centro Enrica Grossi Paoletti, Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy
| | - Ivano Eberini
- Dipartimento di Scienze Farmacologiche e Biomolecolari & DSRC, Università degli Studi di Milano, Milan, Italy.
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8
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Structural analysis of lecithin:cholesterol acyltransferase bound to high density lipoprotein particles. Commun Biol 2020; 3:28. [PMID: 31942029 PMCID: PMC6962161 DOI: 10.1038/s42003-019-0749-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Accepted: 12/17/2019] [Indexed: 02/07/2023] Open
Abstract
Lecithin:cholesterol acyltransferase (LCAT) catalyzes a critical step of reverse cholesterol transport by esterifying cholesterol in high density lipoprotein (HDL) particles. LCAT is activated by apolipoprotein A-I (ApoA-I), which forms a double belt around HDL, however the manner in which LCAT engages its lipidic substrates and ApoA-I in HDL is poorly understood. Here, we used negative stain electron microscopy, crosslinking, and hydrogen-deuterium exchange studies to refine the molecular details of the LCAT-HDL complex. Our data are consistent with LCAT preferentially binding to the edge of discoidal HDL near the boundary between helix 5 and 6 of ApoA-I in a manner that creates a path from the lipid bilayer to the active site of LCAT. Our results provide not only an explanation why LCAT activity diminishes as HDL particles mature, but also direct support for the anti-parallel double belt model of HDL, with LCAT binding preferentially to the helix 4/6 region.
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9
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Tobar HE, Cataldo LR, González T, Rodríguez R, Serrano V, Arteaga A, Álvarez-Mercado A, Lagos CF, Vicuña L, Miranda JP, Pereira A, Bravo C, Aguilera CM, Eyheramendy S, Uauy R, Martínez Á, Gil Á, Francone O, Rigotti A, Santos JL. Identification and functional analysis of missense mutations in the lecithin cholesterol acyltransferase gene in a Chilean patient with hypoalphalipoproteinemia. Lipids Health Dis 2019; 18:132. [PMID: 31164121 PMCID: PMC6549291 DOI: 10.1186/s12944-019-1045-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Accepted: 04/03/2019] [Indexed: 12/16/2022] Open
Abstract
Background Lecithin-cholesterol acyltransferase (LCAT) is a plasma enzyme that esterifies cholesterol in high- and low-density lipoproteins (HDL and LDL). Mutations in LCAT gene causes familial LCAT deficiency, which is characterized by very low plasma HDL-cholesterol levels (Hypoalphalipoproteinemia), corneal opacity and anemia, among other lipid-related traits. Our aim is to evaluate clinical/biochemical features of a Chilean family with a proband showing clinical signs of familial LCAT deficiency, as well as to identify and assess the functional effects of LCAT mutations. Methods An adult female proband with hypoalphalipoproteinemia, corneal opacity and mild anemia, as well as her first-degree relatives, were recruited for clinical, biochemical, genetic, in-silico and in-vitro LCAT analysis. Sequencing of exons and intron-exon boundaries was performed to identify mutations. Site-directed mutagenesis was carried out to generate plasmids containing cDNA with wild type or mutant sequences. Such expression vectors were transfected to HEK-239 T cells to asses the effect of LCAT variants in expression, synthesis, secretion and enzyme activity. In-silico prediction analysis and molecular modeling was also used to evaluate the effect of LCAT variants. Results LCAT sequencing identified rare p.V333 M and p.M404 V missense mutations in compound heterozygous state in the proband, as well the common synonymous p.L363 L variant. LCAT protein was detected in proband’s plasma, but with undetectable enzyme activity compared to control relatives. HEK-293 T transfected cells with vector expression plasmids containing either p.M404 V or p.V333 M cDNA showed detectable LCAT protein expression both in supernatants and lysates from cultured cells, but with much lower enzyme activity compared to cells transfected with the wild-type sequence. Bioinformatic analyses also supported a causal role of such rare variations in LCAT lack of function. Additionally, the proband carried the minor allele of the synonymous p.L363 L variant. However, this variant is unlikely to affect the clinical phenotype of the proband given its relatively high frequency in the Chilean population (4%) and its small putative effect on plasma HDL-cholesterol levels. Conclusion Genetic, biochemical, in vitro and in silico analyses indicate that the rare mutations p.M404 V and p.V333 M in LCAT gene lead to suppression of LCAT enzyme activity and cause clinical features of familial LCAT deficiency. Electronic supplementary material The online version of this article (10.1186/s12944-019-1045-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Hugo E Tobar
- Department of Nutrition, Diabetes and Metabolism, School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Luis R Cataldo
- Department of Nutrition, Diabetes and Metabolism, School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Trinidad González
- Department of Nutrition, Diabetes and Metabolism, School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Ricardo Rodríguez
- Department of Nutrition, Diabetes and Metabolism, School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Valentina Serrano
- Department of Nutrition, Diabetes and Metabolism, School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Antonio Arteaga
- Department of Nutrition, Diabetes and Metabolism, School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
| | | | - Carlos F Lagos
- Facultad de Medicina y Ciencia, Universidad San Sebastián, Campus Los Leones, Santiago, Chile
| | - Lucas Vicuña
- Departamento de Estadísticas, Facultad de Matemáticas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - José P Miranda
- Department of Nutrition, Diabetes and Metabolism, School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
| | | | - Carolina Bravo
- Department of Nutrition, Diabetes and Metabolism, School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Concepción M Aguilera
- Department of Biochemistry and Molecular Biology II, Institute of Nutrition and Food Technology "José Mataix", Center of Biomedical Research, University of Granada, Granada, Spain
| | - Susana Eyheramendy
- Departamento de Estadísticas, Facultad de Matemáticas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Ricardo Uauy
- INTA, Universidad de Chile, Santiago, Chile.,División de Pediatría, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | | | - Ángel Gil
- INYTA, University of Granada, Granada, Spain
| | - Omar Francone
- Pfizer Global Research and Development, San Diego, USA
| | - Attilio Rigotti
- Department of Nutrition, Diabetes and Metabolism, School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile.,Centro de Nutrición Molecular y Enfermedades Crónicas, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - José L Santos
- Department of Nutrition, Diabetes and Metabolism, School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile.
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Manthei KA, Yang SM, Baljinnyam B, Chang L, Glukhova A, Yuan W, Freeman LA, Maloney DJ, Schwendeman A, Remaley AT, Jadhav A, Tesmer JJ. Molecular basis for activation of lecithin:cholesterol acyltransferase by a compound that increases HDL cholesterol. eLife 2018; 7:41604. [PMID: 30479275 PMCID: PMC6277198 DOI: 10.7554/elife.41604] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2018] [Accepted: 11/06/2018] [Indexed: 01/29/2023] Open
Abstract
Lecithin:cholesterol acyltransferase (LCAT) and LCAT-activating compounds are being investigated as treatments for coronary heart disease (CHD) and familial LCAT deficiency (FLD). Herein we report the crystal structure of human LCAT in complex with a potent piperidinylpyrazolopyridine activator and an acyl intermediate-like inhibitor, revealing LCAT in an active conformation. Unlike other LCAT activators, the piperidinylpyrazolopyridine activator binds exclusively to the membrane-binding domain (MBD). Functional studies indicate that the compound does not modulate the affinity of LCAT for HDL, but instead stabilizes residues in the MBD and facilitates channeling of substrates into the active site. By demonstrating that these activators increase the activity of an FLD variant, we show that compounds targeting the MBD have therapeutic potential. Our data better define the substrate binding site of LCAT and pave the way for rational design of LCAT agonists and improved biotherapeutics for augmenting or restoring reverse cholesterol transport in CHD and FLD patients. Cholesterol is a fatty substance found throughout the body that is essential to our health. However, if too much cholesterol builds up in our blood vessels, it can cause blockages that lead to heart and kidney problems. The body removes excess cholesterol by sending out high-density lipoproteins (HDL) that capture the fatty molecules and carry them to the liver where they are eliminated. The first step in this process requires an enzyme called LCAT, which converts cholesterol into a form that HDL particles can efficiently pack and transport. The enzyme acts by interacting with HDL particles, and chemically joining cholesterol with another compound. Finding ways to make LCAT perform better and produce more HDL could improve treatments for heart disease. This could be particularly helpful to people with genetic changes that make LCAT defective. Several small molecules that ‘dial up’ the activity of LCAT have been identified, but how they act on the enzyme is not always well understood. Manthei et al. therefore set out to determine precisely how one such small activator promotes LCAT function. The experiments involved using a method known as crystallography to look at the structure of LCAT when it is attached to the small molecule. They also evaluated the activity of the enzyme and other aspects of the protein in the presence of the small molecule and HDL particles. Taken together, the results led Manthei et al. to suggest that the small molecule works by more efficiently bringing into LCAT the materials that this enzyme needs to create the transport-ready form of cholesterol. The small molecule also partially restored the activity of mutant LCAT found in human disease. This knowledge may help to design more drug-like chemicals to ‘boost’ the activity of LCAT and prevent heart and kidney disease, especially in people who carry a defective version of the enzyme.
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Affiliation(s)
- Kelly A Manthei
- Life Sciences Institute, University of Michigan, Ann Arbor, United States
| | - Shyh-Ming Yang
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, United States
| | - Bolormaa Baljinnyam
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, United States
| | - Louise Chang
- Life Sciences Institute, University of Michigan, Ann Arbor, United States
| | - Alisa Glukhova
- Life Sciences Institute, University of Michigan, Ann Arbor, United States
| | - Wenmin Yuan
- Department of Pharmaceutical Sciences and Biointerfaces Institute, University of Michigan, Ann Arbor, United States
| | - Lita A Freeman
- Lipoprotein Metabolism Section, Cardiovascular-Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, United States
| | - David J Maloney
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, United States
| | - Anna Schwendeman
- Department of Pharmaceutical Sciences and Biointerfaces Institute, University of Michigan, Ann Arbor, United States
| | - Alan T Remaley
- Lipoprotein Metabolism Section, Cardiovascular-Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, United States
| | - Ajit Jadhav
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, United States
| | - John Jg Tesmer
- Department of Biological Sciences, Purdue University, Indiana, United States
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11
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Xu Y, Caldo KMP, Pal-Nath D, Ozga J, Lemieux MJ, Weselake RJ, Chen G. Properties and Biotechnological Applications of Acyl-CoA:diacylglycerol Acyltransferase and Phospholipid:diacylglycerol Acyltransferase from Terrestrial Plants and Microalgae. Lipids 2018; 53:663-688. [PMID: 30252128 DOI: 10.1002/lipd.12081] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2018] [Revised: 07/23/2018] [Accepted: 07/24/2018] [Indexed: 12/14/2022]
Abstract
Triacylglycerol (TAG) is the major storage lipid in most terrestrial plants and microalgae, and has great nutritional and industrial value. Since the demand for vegetable oil is consistently increasing, numerous studies have been focused on improving the TAG content and modifying the fatty-acid compositions of plant seed oils. In addition, there is a strong research interest in establishing plant vegetative tissues and microalgae as platforms for lipid production. In higher plants and microalgae, TAG biosynthesis occurs via acyl-CoA-dependent or acyl-CoA-independent pathways. Diacylglycerol acyltransferase (DGAT) catalyzes the last and committed step in the acyl-CoA-dependent biosynthesis of TAG, which appears to represent a bottleneck in oil accumulation in some oilseed species. Membrane-bound and soluble forms of DGAT have been identified with very different amino-acid sequences and biochemical properties. Alternatively, TAG can be formed through acyl-CoA-independent pathways via the catalytic action of membrane-bound phospholipid:diacylglycerol acyltransferase (PDAT). As the enzymes catalyzing the terminal steps of TAG formation, DGAT and PDAT play crucial roles in determining the flux of carbon into seed TAG and thus have been considered as the key targets for engineering oil production. Here, we summarize the most recent knowledge on DGAT and PDAT in higher plants and microalgae, with the emphasis on their physiological roles, structural features, and regulation. The development of various metabolic engineering strategies to enhance the TAG content and alter the fatty-acid composition of TAG is also discussed.
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Affiliation(s)
- Yang Xu
- Department of Agricultural, Food and Nutritional Science, University of Alberta, 116 Street and 85 Avenue, Edmonton, Alberta, T6G 2P5, Canada
| | - Kristian Mark P Caldo
- Department of Agricultural, Food and Nutritional Science, University of Alberta, 116 Street and 85 Avenue, Edmonton, Alberta, T6G 2P5, Canada
- Department of Biochemistry, University of Alberta, 116 Street and 85 Avenue, Edmonton, Alberta, T6G 2H7, Canada
| | - Dipasmita Pal-Nath
- French Associates Institute for Agriculture and Biotechnology of Drylands, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus, Midreshet Ben-Gurion, 8499000, Israel
| | - Jocelyn Ozga
- Department of Agricultural, Food and Nutritional Science, University of Alberta, 116 Street and 85 Avenue, Edmonton, Alberta, T6G 2P5, Canada
| | - M Joanne Lemieux
- Department of Biochemistry, University of Alberta, 116 Street and 85 Avenue, Edmonton, Alberta, T6G 2H7, Canada
| | - Randall J Weselake
- Department of Agricultural, Food and Nutritional Science, University of Alberta, 116 Street and 85 Avenue, Edmonton, Alberta, T6G 2P5, Canada
| | - Guanqun Chen
- Department of Agricultural, Food and Nutritional Science, University of Alberta, 116 Street and 85 Avenue, Edmonton, Alberta, T6G 2P5, Canada
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Afonso MS, Machado RM, Lavrador MS, Quintao ECR, Moore KJ, Lottenberg AM. Molecular Pathways Underlying Cholesterol Homeostasis. Nutrients 2018; 10:E760. [PMID: 29899250 PMCID: PMC6024674 DOI: 10.3390/nu10060760] [Citation(s) in RCA: 78] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2018] [Revised: 06/10/2018] [Accepted: 06/11/2018] [Indexed: 01/14/2023] Open
Abstract
Cholesterol is an essential molecule that exerts pleiotropic actions. Although its presence is vital to the cell, its excess can be harmful and, therefore, sustaining cholesterol homeostasis is crucial to maintaining proper cellular functioning. It is well documented that high plasma cholesterol concentration increases the risk of atherosclerotic heart disease. In the last decades, several studies have investigated the association of plasma cholesterol concentrations and the risk of cardiovascular diseases as well as the signaling pathways involved in cholesterol homeostasis. Here, we present an overview of several mechanisms involved in intestinal cholesterol absorption, the regulation of cholesterol synthesis and uptake. We also discuss the importance of reverse cholesterol transport and transintestinal cholesterol transport to maintain cholesterol homeostasis and prevent atherosclerosis development. Additionally, we discuss the influence of dietary cholesterol on plasma cholesterol concentration and the new recommendations for cholesterol intake in a context of a healthy dietary pattern.
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Affiliation(s)
- Milessa Silva Afonso
- Marc and Ruti Bell Vascular Biology and Disease Program, Leon H. Charney Division of Cardiology, Department of Medicine, New York University School of Medicine, New York, NY 10016, USA.
| | - Roberta Marcondes Machado
- Laboratorio de Lipides (LIM 10), Hospital das Clínicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, SP 05403-000, Brazil.
| | - Maria Silvia Lavrador
- Laboratorio de Lipides (LIM 10), Hospital das Clínicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, SP 05403-000, Brazil.
| | - Eder Carlos Rocha Quintao
- Laboratorio de Lipides (LIM 10), Hospital das Clínicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, SP 05403-000, Brazil.
| | - Kathryn J Moore
- Marc and Ruti Bell Vascular Biology and Disease Program, Leon H. Charney Division of Cardiology, Department of Medicine, New York University School of Medicine, New York, NY 10016, USA.
- Department of Cell Biology, New York University School of Medicine, New York, NY 10016, USA.
| | - Ana Maria Lottenberg
- Laboratorio de Lipides (LIM 10), Hospital das Clínicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, SP 05403-000, Brazil.
- Faculdade Israelita de Ciências da Saúde, Albert Einstein, São Paulo, SP 05403-000, Brazil.
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