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Zhang W, Liu L, Zhou M, Su S, Dong L, Meng X, Li X, Wang C. Assessing Population Structure and Signatures of Selection in Wanbei Pigs Using Whole Genome Resequencing Data. Animals (Basel) 2022; 13:ani13010013. [PMID: 36611624 PMCID: PMC9817800 DOI: 10.3390/ani13010013] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 12/10/2022] [Accepted: 12/18/2022] [Indexed: 12/24/2022] Open
Abstract
Wanbei pig (WBP) is one of the indigenous pig resources in China and has many germplasm characteristics. However, research on its genome is lacking. To assess the genomic variation, population structure, and selection signatures, we resequenced 18 WBP for the first time and performed a comprehensive analysis with resequenced data of 10 Asian wild boars. In total, 590.03 Gb of data and approximately 41 million variants were obtained. Polymorphism level (θπ) ratio and genetic differentiation (fixation index)-based cross approaches were applied, and 539 regions, which harbored 176 genes, were selected. Functional analysis of the selected genes revealed that they were associated with lipid metabolism (SCP2, APOA1, APOA4, APOC3, CD36, BCL6, ADCY8), backfat thickness (PLAG1, CACNA2D1), muscle (MYOG), and reproduction (CABS1). Overall, our results provide a valuable resource for characterizing the uniqueness of WBP and a basis for future breeding.
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Affiliation(s)
- Wei Zhang
- Key Laboratory of Pig Molecular Quantitative Genetics, Anhui Academy of Agricultural Sciences, Hefei 230031, China
- Anhui Provincial Key Laboratory of Livestock and Poultry Product Safety Engineering, Hefei 230031, China
- Institute of Animal Husbandry and Veterinary Medicine, Anhui Academy of Agricultural Sciences, Hefei 230031, China
| | - Linqing Liu
- Key Laboratory of Pig Molecular Quantitative Genetics, Anhui Academy of Agricultural Sciences, Hefei 230031, China
- Anhui Provincial Key Laboratory of Livestock and Poultry Product Safety Engineering, Hefei 230031, China
- Institute of Animal Husbandry and Veterinary Medicine, Anhui Academy of Agricultural Sciences, Hefei 230031, China
| | - Mei Zhou
- Key Laboratory of Pig Molecular Quantitative Genetics, Anhui Academy of Agricultural Sciences, Hefei 230031, China
- Anhui Provincial Key Laboratory of Livestock and Poultry Product Safety Engineering, Hefei 230031, China
- Institute of Animal Husbandry and Veterinary Medicine, Anhui Academy of Agricultural Sciences, Hefei 230031, China
| | - Shiguang Su
- Key Laboratory of Pig Molecular Quantitative Genetics, Anhui Academy of Agricultural Sciences, Hefei 230031, China
- Anhui Provincial Key Laboratory of Livestock and Poultry Product Safety Engineering, Hefei 230031, China
- Institute of Animal Husbandry and Veterinary Medicine, Anhui Academy of Agricultural Sciences, Hefei 230031, China
| | - Lin Dong
- Key Laboratory of Pig Molecular Quantitative Genetics, Anhui Academy of Agricultural Sciences, Hefei 230031, China
- Institute of Animal Husbandry and Veterinary Medicine, Anhui Academy of Agricultural Sciences, Hefei 230031, China
| | - Xinxin Meng
- Key Laboratory of Pig Molecular Quantitative Genetics, Anhui Academy of Agricultural Sciences, Hefei 230031, China
- Institute of Animal Husbandry and Veterinary Medicine, Anhui Academy of Agricultural Sciences, Hefei 230031, China
| | - Xueting Li
- Key Laboratory of Pig Molecular Quantitative Genetics, Anhui Academy of Agricultural Sciences, Hefei 230031, China
- Institute of Animal Husbandry and Veterinary Medicine, Anhui Academy of Agricultural Sciences, Hefei 230031, China
| | - Chonglong Wang
- Key Laboratory of Pig Molecular Quantitative Genetics, Anhui Academy of Agricultural Sciences, Hefei 230031, China
- Anhui Provincial Key Laboratory of Livestock and Poultry Product Safety Engineering, Hefei 230031, China
- Institute of Animal Husbandry and Veterinary Medicine, Anhui Academy of Agricultural Sciences, Hefei 230031, China
- Correspondence:
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Aygün S, Düzlü Ö, Yıldırım A. Molecular Characterization and Expression Analysis of the Sterol-carrier Protein-2 Fragment in Anopheles sacharovi Generations. TURKIYE PARAZITOLOJII DERGISI 2022; 46:312-321. [PMID: 36444407 DOI: 10.4274/tpd.galenos.2022.68553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Objective It was aimed to characterize the sterol carrier protein-2 (SCP-2) gene in Anopheles sacharovi using molecular methods for the first time, and to reveal the expression levels of An. sacharovi in the developmental stages and female generation in different tissues such as salivary gland, midgut and adipose tissue. Methods The adult female An. sacharovi collected from the Sultan Sazlığı region and the development stages in the insectarium constituted the study material. cDNA isolation was performed following total RNA extraction from An. sacharovi strains. The 216 bp fragment of the SCP-2 gene was amplified with optimized primers in cDNA templates and was sequenced. Genetic characterization of the sequences was provided in silico analysis. Results Twelve of the SCP-2 nucleotide sequences of 14 isolates included in the sequence analysis were 100% identical and the SCP-2 sequences of the other two isolates that were homologous to each other showed a single nucleotide change at base 183. The 216 bp fragment of the SCP-2 gene region was found encoding the 72 amino acid chain. SCP-2 gene sequences clustered the isolates monophyletically on the basis of mosquito species and strains, and that Anopheles sacharovi isolates formed a subcluster together with Anopheles stephensi and Anopheles funestus within the Anopheles cluster in phylogenetic analysis. Because of q-polymerase chain reaction-mediated expression analysis, SCP-2 gene was expressed highest in adult males, followed by an adult female, ss L4, L3, L2, L1, and pupal stages, respectively. In adult female tissues, the SCP-2 gene was expressed the highest in the fat body, followed by the midgut and salivary glands, respectively. Conclusion SCP2, which is an important vaccine candidate or target drug site for Anopheles sacharovi with high vector potential, was firstly characterized in this study and the developmental stages and expression differences in the tissues of the mosquito were revealed.
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Affiliation(s)
- Sümeyye Aygün
- Erciyes Üniversitesi Veteriner Fakültesi, Parazitoloji Anabilim Dalı, Kayseri, Türkiye
| | - Önder Düzlü
- Erciyes Üniversitesi Veteriner Fakültesi, Parazitoloji Anabilim Dalı, Kayseri, Türkiye
| | - Alparslan Yıldırım
- Erciyes Üniversitesi Veteriner Fakültesi, Parazitoloji Anabilim Dalı, Kayseri, Türkiye
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Poudyal NR, Paul KS. Fatty acid uptake in Trypanosoma brucei: Host resources and possible mechanisms. Front Cell Infect Microbiol 2022; 12:949409. [PMID: 36478671 PMCID: PMC9719944 DOI: 10.3389/fcimb.2022.949409] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 10/24/2022] [Indexed: 11/22/2022] Open
Abstract
Trypanosoma brucei spp. causes African Sleeping Sickness in humans and nagana, a wasting disease, in cattle. As T. brucei goes through its life cycle in its mammalian and insect vector hosts, it is exposed to distinct environments that differ in their nutrient resources. One such nutrient resource is fatty acids, which T. brucei uses to build complex lipids or as a potential carbon source for oxidative metabolism. Of note, fatty acids are the membrane anchoring moiety of the glycosylphosphatidylinositol (GPI)-anchors of the major surface proteins, Variant Surface Glycoprotein (VSG) and the Procyclins, which are implicated in parasite survival in the host. While T. brucei can synthesize fatty acids de novo, it also readily acquires fatty acids from its surroundings. The relative contribution of parasite-derived vs. host-derived fatty acids to T. brucei growth and survival is not known, nor have the molecular mechanisms of fatty acid uptake been defined. To facilitate experimental inquiry into these important aspects of T. brucei biology, we addressed two questions in this review: (1) What is known about the availability of fatty acids in different host tissues where T. brucei can live? (2) What is known about the molecular mechanisms mediating fatty acid uptake in T. brucei? Finally, based on existing biochemical and genomic data, we suggest a model for T. brucei fatty acid uptake that proposes two major routes of fatty acid uptake: diffusion across membranes followed by intracellular trapping, and endocytosis of host lipoproteins.
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Affiliation(s)
- Nava Raj Poudyal
- Department of Genetics and Biochemistry, Clemson University, Clemson, SC, United States,Eukaryotic Pathogens Innovation Center (EPIC), Clemson University, Clemson, SC, United States
| | - Kimberly S. Paul
- Department of Genetics and Biochemistry, Clemson University, Clemson, SC, United States,Eukaryotic Pathogens Innovation Center (EPIC), Clemson University, Clemson, SC, United States,*Correspondence: Kimberly S. Paul,
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4
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Xu C, Li H, Tang CK. Sterol carrier protein 2 in lipid metabolism and non-alcoholic fatty liver disease: Pathophysiology, molecular biology, and potential clinical implications. Metabolism 2022; 131:155180. [PMID: 35311663 DOI: 10.1016/j.metabol.2022.155180] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 02/03/2022] [Accepted: 03/13/2022] [Indexed: 11/29/2022]
Abstract
Non-alcoholic fatty liver disease (NAFLD) is considered as the most common chronic liver disease and has become a rapidly global public health problem. Sterol carrier protein 2 (SCP-2), also called non-specific lipid-transfer protein, is predominantly expressed by the liver. SCP-2 plays a key role in intracellular lipid transport and metabolism. SCP-2 has been closely implicated in the development of NAFLD-related metabolic disorders, such as obesity, atherosclerosis, Type 2 diabetes mellitus (T2DM), and gallstones. Recent studies indicate that SCP-2 plays a beneficial role in NAFLD by regulating cholesterol-, endocannabinoid-, and fatty acid-related aspects of lipid metabolism. Hence, in this paper, we summarize the latest findings about the roles of SCP-2 in hepatic steatosis and further describe its molecular function in the pathogenesis of NAFLD.
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Affiliation(s)
- Can Xu
- Institute of Cardiovascular Disease, Key Laboratory for Arteriosclerology of Hunan Province, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, The First Affiliated Hospital of University of South China, Department of Cardiology, Hengyang Medical School, University of South China, Hengyang, Hunan 421001, PR China
| | - Heng Li
- Institute of Cardiovascular Disease, Key Laboratory for Arteriosclerology of Hunan Province, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, The First Affiliated Hospital of University of South China, Department of Cardiology, Hengyang Medical School, University of South China, Hengyang, Hunan 421001, PR China.
| | - Chao-Ke Tang
- Institute of Cardiovascular Disease, Key Laboratory for Arteriosclerology of Hunan Province, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, The First Affiliated Hospital of University of South China, Department of Cardiology, Hengyang Medical School, University of South China, Hengyang, Hunan 421001, PR China.
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Identification of Six Thiolases and their Effects on Fatty Acid and Ergosterol Biosynthesis in Aspergillus oryzae. Appl Environ Microbiol 2022; 88:e0237221. [PMID: 35138925 DOI: 10.1128/aem.02372-21] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Thiolase plays important roles in lipid metabolism. It can be divided into degradative thiolases (Thioase I) and biosynthetic thiolases (thiolases II), which are involved in fatty acid β-oxidation and acetoacetyl-CoA biosynthesis, respectively. The Saccharomyces cerevisiae (S. cerevisiae) genome harbors only one gene each for thioase I and thiolase II, namely, Pot1 and Erg10, respectively. In this study, six thiolases (named AoErg10A-AoErg10F) were identified in Aspergillus oryzae (A. oryzae) genome using bioinformatics analysis. Quantitative reverse transcription-PCR (qRT-PCR) indicated that the expression of these six thiolases varied at different growth time and under different forms of abiotic stress. Subcellular localization analysis showed that AoErg10A was located in the cytoplasm, AoErg10B and AoErg10C in the mitochondria, and AoErg10D-AoErg10F in the peroxisome. Yeast heterologous complementation assays revealed that AoErg10A, AoErg10D, AoErg10E, AoErg10F and cytoplasmic AoErg10B (AoErg10BΔMTS) recovered the phenotypes of S. cerevisiae erg10 weak and lethal mutants, and that only AoErg10D-F recovered the phenotype of the pot1 mutant that cannot use oleic acid as the carbon source. Overexpression of AoErg10s either affected the growth speed or sporulation of the transgenic strains. In addition, the fatty acid and ergosterol content changed in all the AoErg10-overexpressing strains. This study revealed the function of six thiolases in A. oryzae and their effect on growth, and fatty acid and ergosterol biosynthesis, which may lay the foundation for genetic engineering for lipid metabolism in A. oryzae or other fungi. Importance Thiolase including thioase I and thiolase II, plays important roles in lipid metabolism. A. oryzae, one of the most industrially important filamentous fungi, has been widely used for manufacturing oriental fermented food such as sauce, miso, and sake for a long time. Besides, A. oryzae has a high capability in production of high lipid content and has been used for lipid production. Thus, it is very important to investigate the function of thiolases in A. oryzae. In this study, six thiolase (named AoErg10A-AoErg10F) were identified by bioinformatics analysis. Unlike other reported thiolases in fungi, three of the six thiolases showed dual function of thioase I and thiolase II in S. cerevisiae, indicating the lipid metabolism is more complex in A. oryzae. The reveal of function of these thiolases in A. oryzae can lay the foundation for genetic engineering for lipid metabolism in A. oryzae or other fungi.
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Xu C, Li H, Tang CK. Sterol Carrier Protein 2: A promising target in the pathogenesis of atherosclerosis. Genes Dis 2022; 10:457-467. [DOI: 10.1016/j.gendis.2021.12.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 11/21/2021] [Accepted: 12/01/2021] [Indexed: 10/19/2022] Open
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Girotti AW, Korytowski W. Pathophysiological potential of lipid hydroperoxide intermembrane translocation: Cholesterol hydroperoxide translocation as a special case. Redox Biol 2021; 46:102096. [PMID: 34418596 PMCID: PMC8379493 DOI: 10.1016/j.redox.2021.102096] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 08/04/2021] [Accepted: 08/05/2021] [Indexed: 10/29/2022] Open
Abstract
Peroxidation of unsaturated phospholipids, glycolipids, and cholesterol in biological membranes under oxidative stress conditions can underlie a variety of pathological conditions, including atherogenesis, neurodegeneration, and carcinogenesis. Lipid hydroperoxides (LOOHs) are key intermediates in the peroxidative process. Nascent LOOHs may either undergo one-electron reduction to exacerbate membrane damage/dysfunction or two-electron reduction to attenuate this. Another possibility is LOOH translocation to an acceptor site, followed by either of these competing reductions. Cholesterol (Ch)-derived hydroperoxides (ChOOHs) have several special features that will be highlighted in this review. In addition to being susceptible to one-electron vs. two-electron reduction, ChOOHs can translocate from a membrane of origin to another membrane, where such turnover may ensue. Intracellular StAR family proteins have been shown to deliver not only Ch to mitochondria, but also ChOOHs. StAR-mediated transfer of free radical-generated 7-hydroperoxycholesterol (7-OOH) results in impairment of (a) Ch utilization in steroidogenic cells, and (b) anti-atherogenic reverse Ch transport in vascular macrophages. This is the first known example of how a peroxide derivative can be recognized by a natural lipid trafficking pathway with deleterious consequences. For each example above, we will discuss the underlying mechanism of oxidative damage/dysfunction, and how this might be mitigated by antioxidant intervention.
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Affiliation(s)
- Albert W Girotti
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI, USA.
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Ramírez-Nuñez O, Jové M, Torres P, Sol J, Fontdevila L, Romero-Guevara R, Andrés-Benito P, Ayala V, Rossi C, Boada J, Povedano M, Ferrer I, Pamplona R, Portero-Otin M. Nuclear lipidome is altered in amyotrophic lateral sclerosis: A pilot study. J Neurochem 2021; 158:482-499. [PMID: 33905537 DOI: 10.1111/jnc.15373] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 03/28/2021] [Accepted: 04/12/2021] [Indexed: 12/13/2022]
Abstract
Nucleocytosolic transport, a membrane process, is impaired in motor neurons in amyotrophic lateral sclerosis (ALS). This study analyzes the nuclear lipidome in motor neurons in ALS and examines molecular pathways linked to the major lipid alterations. Nuclei were obtained from the frozen anterior horn of the lumbar spinal cord of ALS patients and age-matched controls. Lipidomic profiles of this subcellular fraction were obtained using liquid chromatography and mass spectrometry. We validated the mechanisms behind presumable lipidomic changes by exploring ALS surrogate models including human motor neurons (derived from ALS lines and controls) subjected to oxidative stress, the hSOD-G93A transgenic mice, and samples from an independent cohort of ALS patients. Among the differential lipid species, we noted 41 potential identities, mostly belonging to phospholipids (particularly ether phospholipids, as plasmalogens), as well as diacylglycerols and triacylglycerides. Decreased expression of alkyldihydroxyacetonephosphate synthase (AGPS)-a critical peroxisomal enzyme in plasmalogen synthesis-is found in motor neuron disease models; this occurs in parallel with an increase in the expression of sterol carrier protein 2 (SCP2) mRNA in ALS and Scp2 levels in G93A transgenic mice. Further, we identified diminished expression of diacylglycerol-related enzymes, such as phospholipase C βI (PLCβI) and protein kinase CβII (PKCβII), linked to diacylglycerol metabolism. Finally, lipid droplets were recognized in the nuclei, supporting the identification of triacylglycerides as differential lipids. Our results point to the potentially pathogenic role of altered composition of nuclear membrane lipids and lipids in the nucleoplasm in the anterior horn of the spinal cord in ALS. Overall, these data support the usefulness of subcellular lipidomics applied to neurodegenerative diseases.
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Affiliation(s)
- Omar Ramírez-Nuñez
- Department of Experimental Medicine, School of Medicine, IRBLleida-UdL, Lleida, Spain
| | - Mariona Jové
- Department of Experimental Medicine, School of Medicine, IRBLleida-UdL, Lleida, Spain
| | - Pascual Torres
- Department of Experimental Medicine, School of Medicine, IRBLleida-UdL, Lleida, Spain
| | - Joaquim Sol
- Department of Experimental Medicine, School of Medicine, IRBLleida-UdL, Lleida, Spain.,Institut Català de la Salut, Lleida, Spain.,Research Support Unit Lleida, Fundació Institut Universitari per a la recerca a l'Atenció Primària de Salut Jordi Gol i Gurina (IDIAPJGol), Lleida, Spain
| | - Laia Fontdevila
- Department of Experimental Medicine, School of Medicine, IRBLleida-UdL, Lleida, Spain
| | | | - Pol Andrés-Benito
- Departament of Pathology and Experimental Therapeutics, Hospital Universitari de Bellvitge, IDIBELL, Universitat de Barcelona, Hospitalet de Llobregat, Spain.,CIBERNED (Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas), Instituto Carlos III, Barcelona, Spain
| | - Victòria Ayala
- Department of Experimental Medicine, School of Medicine, IRBLleida-UdL, Lleida, Spain
| | - Chiara Rossi
- Department of Experimental Medicine, School of Medicine, IRBLleida-UdL, Lleida, Spain
| | - Jordi Boada
- Department of Experimental Medicine, School of Medicine, IRBLleida-UdL, Lleida, Spain
| | - Mònica Povedano
- Neurology Service, Hospital Universitari de Bellvitge, Barcelona, Spain
| | - Isidro Ferrer
- Departament of Pathology and Experimental Therapeutics, Hospital Universitari de Bellvitge, IDIBELL, Universitat de Barcelona, Hospitalet de Llobregat, Spain.,CIBERNED (Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas), Instituto Carlos III, Barcelona, Spain
| | - Reinald Pamplona
- Department of Experimental Medicine, School of Medicine, IRBLleida-UdL, Lleida, Spain
| | - Manuel Portero-Otin
- Department of Experimental Medicine, School of Medicine, IRBLleida-UdL, Lleida, Spain
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Gutiérrez-García L, Arró M, Altabella T, Ferrer A, Boronat A. Structural and functional analysis of tomato sterol C22 desaturase. BMC PLANT BIOLOGY 2021; 21:141. [PMID: 33731007 PMCID: PMC7972189 DOI: 10.1186/s12870-021-02898-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 02/21/2021] [Indexed: 06/12/2023]
Abstract
BACKGROUND Sterols are structural and functional components of eukaryotic cell membranes. Plants produce a complex mixture of sterols, among which β-sitosterol, stigmasterol, campesterol, and cholesterol in some Solanaceae, are the most abundant species. Many reports have shown that the stigmasterol to β-sitosterol ratio changes during plant development and in response to stresses, suggesting that it may play a role in the regulation of these processes. In tomato (Solanum lycopersicum), changes in the stigmasterol to β-sitosterol ratio correlate with the induction of the only gene encoding sterol C22-desaturase (C22DES), the enzyme specifically involved in the conversion of β-sitosterol to stigmasterol. However, despite the biological interest of this enzyme, there is still a lack of knowledge about several relevant aspects related to its structure and function. RESULTS In this study we report the subcellular localization of tomato C22DES in the endoplasmic reticulum (ER) based on confocal fluorescence microscopy and cell fractionation analyses. Modeling studies have also revealed that C22DES consists of two well-differentiated domains: a single N-terminal transmembrane-helix domain (TMH) anchored in the ER-membrane and a globular (or catalytic) domain that is oriented towards the cytosol. Although TMH is sufficient for the targeting and retention of the enzyme in the ER, the globular domain may also interact and be retained in the ER in the absence of the N-terminal transmembrane domain. The observation that a truncated version of C22DES lacking the TMH is enzymatically inactive revealed that the N-terminal membrane domain is essential for enzyme activity. The in silico analysis of the TMH region of plant C22DES revealed several structural features that could be involved in substrate recognition and binding. CONCLUSIONS Overall, this study contributes to expand the current knowledge on the structure and function of plant C22DES and to unveil novel aspects related to plant sterol metabolism.
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Affiliation(s)
- Laura Gutiérrez-García
- Center for Research in Agricultural Genomics (CSIC-IRTA-UAB-UB), Bellaterra, Barcelona, Spain
| | - Montserrat Arró
- Center for Research in Agricultural Genomics (CSIC-IRTA-UAB-UB), Bellaterra, Barcelona, Spain
- Department of Biochemistry and Physiology, Faculty of Pharmacy and Food Sciences, University of Barcelona, 08028, Barcelona, Spain
| | - Teresa Altabella
- Center for Research in Agricultural Genomics (CSIC-IRTA-UAB-UB), Bellaterra, Barcelona, Spain
- Department of Biology, Healthcare and the Environment, Faculty of Pharmacy and Food Sciences, University of Barcelona, 08028, Barcelona, Spain
| | - Albert Ferrer
- Center for Research in Agricultural Genomics (CSIC-IRTA-UAB-UB), Bellaterra, Barcelona, Spain
- Department of Biochemistry and Physiology, Faculty of Pharmacy and Food Sciences, University of Barcelona, 08028, Barcelona, Spain
| | - Albert Boronat
- Center for Research in Agricultural Genomics (CSIC-IRTA-UAB-UB), Bellaterra, Barcelona, Spain.
- Department of Biochemistry and Molecular Biomedicine, Faculty of Biology, University of Barcelona, 08028, Barcelona, Spain.
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Gianotti AR, Klinke S, Ermácora MR. The structure of unliganded sterol carrier protein 2 from Yarrowia lipolytica unveils a mechanism for binding site occlusion. J Struct Biol 2020; 213:107675. [PMID: 33278583 DOI: 10.1016/j.jsb.2020.107675] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 11/21/2020] [Accepted: 11/27/2020] [Indexed: 11/19/2022]
Abstract
Isolated or as a part of multidomain proteins, Sterol Carrier Protein 2 (SCP2) exhibits high affinity and broad specificity for different lipidic and hydrophobic compounds. A wealth of structural information on SCP2 domains in all forms of life is currently available; however, many aspects of its ligand binding activity are poorly understood. ylSCP2 is a well-characterized single domain SCP2 from the yeast Yarrowia lipolytica. Herein, we report the X-ray structure of unliganded ylSCP2 refined to 2.0 Å resolution. Comparison with the previously solved liganded ylSCP2 structure unveiled a novel mechanism for binding site occlusion. The liganded ylSCP2 binding site is a large cavity with a volume of more than 800 Å3. In unliganded ylSCP2 the binding site is reduced to about 140 Å3. The obliteration is caused by a swing movement of the C-terminal α helix 5 and a subtle compaction of helices 2-4. Previous pairwise comparisons were between homologous SCP2 domains with a uncertain binding status. The reported unliganded ylSCP2 structure allows for the first time a fully controlled comparative analysis of the conformational effects of ligand occupation dispelling several doubts regarding the architecture of SCP2 binding site.
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Affiliation(s)
- Alejo R Gianotti
- Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Argentina; Grupo de Biología Estructural y Biotecnología, IMBICE, CONICET, Universidad Nacional de Quilmes, Argentina
| | - Sebastián Klinke
- Fundación Instituto Leloir, IIBBA-CONICET, and Plataforma Argentina de Biología Estructural y Metabolómica PLABEM, Buenos Aires, Argentina
| | - Mario R Ermácora
- Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Argentina; Grupo de Biología Estructural y Biotecnología, IMBICE, CONICET, Universidad Nacional de Quilmes, Argentina.
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11
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Wang X, Zheng R, Yao Q, Liang Z, Wu M, Wang H. Effects of fluoride on the histology, lipid metabolism, and bile acid secretion in liver of Bufo gargarizans larvae. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 254:113052. [PMID: 31465901 DOI: 10.1016/j.envpol.2019.113052] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 07/12/2019] [Accepted: 08/11/2019] [Indexed: 06/10/2023]
Abstract
In our study, Bufo gargarizans (B. gargarizans) larvae were exposed to control, 0.5, 5, 10 and 50 mg/L of NaF from Gs 26 to 42. At Gs 42, we evaluated the changes of liver histology and the mRNA levels of target genes in liver. In addition, we also examined the composition and content of fatty acids. Histological analysis revealed that fluoride caused liver injury, such as the increase of number of melanomacrophage centres, atrophy of nucleus, dilation of bile canaliculus, and decrease of quantity, degradation and deposition of lipid droplets. The results of RT-qPCR indicated that exposure to 5, 10 and 50 mg/L of NaF significantly decreased the transcript levels of genes related to fatty acid synthesis (FASN, FAE, MECR, KAR and TECR) in liver. Besides, mRNA expression of genes involved in fatty acid β-oxidation (ECHS1, HADHA, SCP2, CPT2, ACAA1 and ACAA2) and oxidative stress (SOD, GPx, MICU1 and HSP90) was significantly downregulated in 0.5, 5, 10 and 50 mg/L of NaF treatment groups. Also, in the relative expression of genes associated with synthesis and secretion of bile acid, BSEP significantly increased at 0.5, 5 and 50 mg/L of NaF while HSD3B7 significantly reduced in 0.5, 5, 10 and 50 mg/L of NaF. Finally, the fatty acid extraction and GC-MS analysis showed that the content of saturated fatty acids (SFAs) was decreased and the content of polyunsaturated fatty acids (PUFAs) was increased in all fluoride treatment groups. Taken together, the present results indicated that fluoride-induced the histological alterations of liver might be linked to the disorder of lipid metabolism, oxidative damage.
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Affiliation(s)
- Xianchan Wang
- College of Life Science, Shaanxi Normal University, Xi'an, 710119, PR China
| | - Rui Zheng
- College of Life Science, Shaanxi Normal University, Xi'an, 710119, PR China
| | - Qiong Yao
- College of Life Science, Shaanxi Normal University, Xi'an, 710119, PR China
| | - Zhijia Liang
- College of Life Science, Shaanxi Normal University, Xi'an, 710119, PR China
| | - Minyao Wu
- College of Life Science, Shaanxi Normal University, Xi'an, 710119, PR China
| | - Hongyuan Wang
- College of Life Science, Shaanxi Normal University, Xi'an, 710119, PR China.
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12
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Luo J, Jiang LY, Yang H, Song BL. Intracellular Cholesterol Transport by Sterol Transfer Proteins at Membrane Contact Sites. Trends Biochem Sci 2019; 44:273-292. [DOI: 10.1016/j.tibs.2018.10.001] [Citation(s) in RCA: 70] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 10/06/2018] [Accepted: 10/10/2018] [Indexed: 12/20/2022]
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13
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The peroxisomal zebrafish SCP2-thiolase (type-1) is a weak transient dimer as revealed by crystal structures and native mass spectrometry. Biochem J 2019; 476:307-332. [PMID: 30573650 DOI: 10.1042/bcj20180788] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Revised: 12/12/2018] [Accepted: 12/20/2018] [Indexed: 12/19/2022]
Abstract
The SCP2 (sterol carrier protein 2)-thiolase (type-1) functions in the vertebrate peroxisomal, bile acid synthesis pathway, converting 24-keto-THC-CoA and CoA into choloyl-CoA and propionyl-CoA. This conversion concerns the β-oxidation chain shortening of the steroid fatty acyl-moiety of 24-keto-THC-CoA. This class of dimeric thiolases has previously been poorly characterized. High-resolution crystal structures of the zebrafish SCP2-thiolase (type-1) now reveal an open catalytic site, shaped by residues of both subunits. The structure of its non-dimerized monomeric form has also been captured in the obtained crystals. Four loops at the dimer interface adopt very different conformations in the monomeric form. These loops also shape the active site and their structural changes explain why a competent active site is not present in the monomeric form. Native mass spectrometry studies confirm that the zebrafish SCP2-thiolase (type-1) as well as its human homolog are weak transient dimers in solution. The crystallographic binding studies reveal the mode of binding of CoA and octanoyl-CoA in the active site, highlighting the conserved geometry of the nucleophilic cysteine, the catalytic acid/base cysteine and the two oxyanion holes. The dimer interface of SCP2-thiolase (type-1) is equally extensive as in other thiolase dimers; however, it is more polar than any of the corresponding interfaces, which correlates with the notion that the enzyme forms a weak transient dimer. The structure comparison of the monomeric and dimeric forms suggests functional relevance of this property. These comparisons provide also insights into the structural rearrangements that occur when the folded inactive monomers assemble into the mature dimer.
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Krombach S, Reissmann S, Kreibich S, Bochen F, Kahmann R. Virulence function of the Ustilago maydis sterol carrier protein 2. THE NEW PHYTOLOGIST 2018; 220:553-566. [PMID: 29897130 DOI: 10.1111/nph.15268] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 05/14/2018] [Indexed: 05/06/2023]
Abstract
The peroxisomal sterol carrier protein 2 (Scp2) of the biotrophic maize pathogen Ustilago maydis was detected in apoplastic fluid, suggesting that it might function as a secreted effector protein. Here we analyze the role of the scp2 gene during plant colonization. We used reverse genetics approaches to delete the scp2 gene, determined stress sensitivity and fatty acid utilization of mutants, demonstrated secretion of Scp2, used quantitative reverse transcription polymerase chain reaction for expression analysis and expressed GFP-Scp2 fusion proteins for protein localization. scp2 mutants were strongly attenuated in virulence and this defect manifested itself during penetration. Scp2 localized to peroxisomes and peroxisomal targeting was necessary for its virulence function. Deletion of scp2 in U. maydis interfered neither with growth nor with peroxisomal β-oxidation. Conventionally secreted Scp2 protein could not rescue the virulence defect. scp2 mutants displayed an altered localization of peroxisomes. Our results show a virulence function for Scp2 during penetration that is probably carried out by Scp2 in peroxisomes. We speculate that Scp2 affects the lipid composition of membranes and in this way ensures the even cellular distribution of peroxisomes.
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Affiliation(s)
- Sina Krombach
- Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch-Strasse 10, 35043, Marburg, Germany
| | - Stefanie Reissmann
- Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch-Strasse 10, 35043, Marburg, Germany
| | - Saskia Kreibich
- Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch-Strasse 10, 35043, Marburg, Germany
| | - Florian Bochen
- Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch-Strasse 10, 35043, Marburg, Germany
| | - Regine Kahmann
- Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch-Strasse 10, 35043, Marburg, Germany
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15
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A phosphatidic acid-binding protein is important for lipid homeostasis and adaptation to anaerobic biofilm conditions in Pseudomonas aeruginosa. Biochem J 2018; 475:1885-1907. [DOI: 10.1042/bcj20180257] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Revised: 04/27/2018] [Accepted: 05/01/2018] [Indexed: 01/22/2023]
Abstract
A quantitative Pseudomonas aeruginosa proteomics approach revealed increased abundance of the so-far uncharacterized protein PA3911 in anaerobic biofilms grown under conditions of the cystic fibrosis lung. Physiological relevance of ORF PA3911 was demonstrated, inter alia, using phenotype microarray experiments. The mutant strain showed increased susceptibility in the presence of antimicrobials (minocycline, nafcillin, oxacillin, chloramphenicol and thiamphenicol), enhanced twitching motility and significantly impaired biofilm formation. PA3911 is a soluble, cytoplasmic protein in P. aeruginosa. In protein–lipid overlay experiments, purified PA3911 bound specifically to phosphatidic acid (PA), the central hub of phospholipid metabolism. Structure-guided site-directed mutagenesis was used to explore the proposed ligand-binding cavity of PA3911. Protein variants of Leu56, Leu58, Val69 and Leu114 were shown to impair PA interaction. A comparative shotgun lipidomics approach demonstrated a multifaceted response of P. aeruginosa to anaerobic conditions at the lipid head group and fatty acid level. Lipid homeostasis in the PA3911 mutant strain was imbalanced with respect to lysophosphatidylcholine, phosphatidylcholine and diacylglycerol under anaerobic and/or aerobic conditions. The impact of the newly identified PA-binding protein on lipid homeostasis and the related macroscopic phenotypes of P. aeruginosa are discussed.
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16
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Santos AL, Preta G. Lipids in the cell: organisation regulates function. Cell Mol Life Sci 2018; 75:1909-1927. [PMID: 29427074 PMCID: PMC11105414 DOI: 10.1007/s00018-018-2765-4] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Revised: 01/04/2018] [Accepted: 01/29/2018] [Indexed: 12/19/2022]
Abstract
Lipids are fundamental building blocks of all cells and play important roles in the pathogenesis of different diseases, including inflammation, autoimmune disease, cancer, and neurodegeneration. The lipid composition of different organelles can vary substantially from cell to cell, but increasing evidence demonstrates that lipids become organised specifically in each compartment, and this organisation is essential for regulating cell function. For example, lipid microdomains in the plasma membrane, known as lipid rafts, are platforms for concentrating protein receptors and can influence intra-cellular signalling. Lipid organisation is tightly regulated and can be observed across different model organisms, including bacteria, yeast, Drosophila, and Caenorhabditis elegans, suggesting that lipid organisation is evolutionarily conserved. In this review, we summarise the importance and function of specific lipid domains in main cellular organelles and discuss recent advances that investigate how these specific and highly regulated structures contribute to diverse biological processes.
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Affiliation(s)
- Ana L Santos
- Institut National de la Santé et de la Recherche Médicale, U1001 and Faculté de Médecine, Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Giulio Preta
- Institute of Biochemistry, Vilnius University, Sauletekio 7, LT-10257, Vilnius, Lithuania.
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Bo X, Mu D, Wu M, Xiao H, Wang H. The morphological changes and molecular biomarker responses in the liver of fluoride-exposed Bufo gargarizans larvae. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2018; 151:199-205. [PMID: 29367176 DOI: 10.1016/j.ecoenv.2018.01.027] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 01/09/2018] [Accepted: 01/11/2018] [Indexed: 06/07/2023]
Abstract
The goal of the current study was to evaluate the negative influences of fluoride on liver of Bufo gargarizans larvae. B. gargarizans larvae were treated with 42.4mgF-/L for 0, 24, 48 and 72h at Gosner stage 37. The morphological changes and responses of molecular biomarkers involved in lipid metabolism, oxidative stress and apoptosis were examined in liver. Disappearance of cell boundaries, degeneration of hepatic parenchyma cells and significant increase in the number of melanomacrophage centres and the quantity of lipid droplets were found in the liver treated with 42.4mgF-/L for 72h. In addition, in the relative expression of acetyl CoA carboxylase 1 (ACC-1), fatty acid elongase 1 (FAE-1), sterol carrier protein 2 (SCP-2), and carnitine palmitoyltransferase-1 (CPT-1), decrease was observed after 24, 48 and 72h of 42.4mgF-/L exposure. Furthermore, the transcript levels of superoxide dismutase (SOD) and glutathione peroxidase (GPx) were downregulated in tadpoles exposed for 24, 48 and 72h to 42.4mgF-/L, while the transcript level of heat shock protein 90 (HSP90) was upregulated at 42.4mgF-/L for 72h. Also, mRNA expression of Bcl-2-associated transcription factor 1(BCLAF1) and thyroid hormone receptors (TRα and TRβ) was significantly upregulated in tadpoles treated with 42.4mgF-/L for 72h. Therefore, our results suggested that the liver injury induced by fluoride might result from disruption of lipid metabolism, oxidative damage and apoptosis.
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Affiliation(s)
- Xiaoxue Bo
- College of Life Science, Shaanxi Normal University, Xi'an 710119, China
| | - Danyang Mu
- College of Life Science, Shaanxi Normal University, Xi'an 710119, China
| | - Minyao Wu
- College of Life Science, Shaanxi Normal University, Xi'an 710119, China
| | - Hui Xiao
- College of Life Science, Shaanxi Normal University, Xi'an 710119, China
| | - Hongyuan Wang
- College of Life Science, Shaanxi Normal University, Xi'an 710119, China.
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18
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McIntosh AL, Storey SM, Huang H, Kier AB, Schroeder F. Sex-dependent impact of Scp-2/Scp-x gene ablation on hepatic phytol metabolism. Arch Biochem Biophys 2017; 635:17-26. [PMID: 29051070 DOI: 10.1016/j.abb.2017.10.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Revised: 10/10/2017] [Accepted: 10/14/2017] [Indexed: 12/19/2022]
Abstract
While prior studies focusing on male mice suggest a role for sterol carrier protein-2/sterol carrier protein-x (SCP-2/SCP-x; DKO) on hepatic phytol metabolism, its role in females is unresolved. This issue was addressed using female and male wild-type (WT) and DKO mice fed a phytoestrogen-free diet without or with 0.5% phytol. GC/MS showed that hepatic: i) phytol was absent and its branched-chain fatty acid (BCFA) metabolites were barely detectable in WT control-fed mice; ii) accumulation of phytol as well as its peroxisomal metabolite BCFAs (phytanic acid » pristanic and 2,3-pristenic acids) was increased by dietary phytol in WT females, but only slightly in WT males; iii) accumulation of phytol and BCFA was further increased by DKO in phytol-fed females, but much more markedly in males. Livers of phytol-fed WT female mice as well as phytol-fed DKO female and male mice also accumulated increased proportion of saturated straight-chain fatty acids (LCFA) at the expense of unsaturated LCFA. Liver phytol accumulation was not due to increased SCP-2 binding/transport of phytol since SCP-2 bound phytanic acid, but not its precursor phytol. Thus, the loss of Scp-2/Scp-x contributed to a sex-dependent hepatic accumulation of dietary phytol and BCFA.
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Affiliation(s)
- Avery L McIntosh
- Department of Physiology and Pharmacology, Texas A&M University, TVMC, College Station, TX 77843-4466, United States
| | - Stephen M Storey
- Department of Physiology and Pharmacology, Texas A&M University, TVMC, College Station, TX 77843-4466, United States
| | - Huan Huang
- Department of Physiology and Pharmacology, Texas A&M University, TVMC, College Station, TX 77843-4466, United States
| | - Ann B Kier
- Department of Pathobiology, Texas A&M University, TVMC, College Station, TX 77843-4467, United States
| | - Friedhelm Schroeder
- Department of Physiology and Pharmacology, Texas A&M University, TVMC, College Station, TX 77843-4466, United States.
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20
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Loiseau L, Fyfe C, Aussel L, Hajj Chehade M, Hernández SB, Faivre B, Hamdane D, Mellot-Draznieks C, Rascalou B, Pelosi L, Velours C, Cornu D, Lombard M, Casadesús J, Pierrel F, Fontecave M, Barras F. The UbiK protein is an accessory factor necessary for bacterial ubiquinone (UQ) biosynthesis and forms a complex with the UQ biogenesis factor UbiJ. J Biol Chem 2017; 292:11937-11950. [PMID: 28559279 DOI: 10.1074/jbc.m117.789164] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 05/08/2017] [Indexed: 11/06/2022] Open
Abstract
Ubiquinone (UQ), also referred to as coenzyme Q, is a widespread lipophilic molecule in both prokaryotes and eukaryotes in which it primarily acts as an electron carrier. Eleven proteins are known to participate in UQ biosynthesis in Escherichia coli, and we recently demonstrated that UQ biosynthesis requires additional, nonenzymatic factors, some of which are still unknown. Here, we report on the identification of a bacterial gene, yqiC, which is required for efficient UQ biosynthesis, and which we have renamed ubiK Using several methods, we demonstrated that the UbiK protein forms a complex with the C-terminal part of UbiJ, another UQ biogenesis factor we previously identified. We found that both proteins are likely to contribute to global UQ biosynthesis rather than to a specific biosynthetic step, because both ubiK and ubiJ mutants accumulated octaprenylphenol, an early intermediate of the UQ biosynthetic pathway. Interestingly, we found that both proteins are dispensable for UQ biosynthesis under anaerobiosis, even though they were expressed in the absence of oxygen. We also provide evidence that the UbiK-UbiJ complex interacts with palmitoleic acid, a major lipid in E. coli Last, in Salmonella enterica, ubiK was required for proliferation in macrophages and virulence in mice. We conclude that although the role of the UbiK-UbiJ complex remains unknown, our results support the hypothesis that UbiK is an accessory factor of Ubi enzymes and facilitates UQ biosynthesis by acting as an assembly factor, a targeting factor, or both.
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Affiliation(s)
- Laurent Loiseau
- Aix Marseille Université, CNRS, Laboratoire de Chimie Bactérienne (LCB) UMR 7283, Institut de Microbiologie de la Méditerranée (IMM), 13402, Marseille, France
| | - Cameron Fyfe
- Laboratoire de Chimie des Processus Biologiques, UMR8229 CNRS, Collège de France, Université Pierre et Marie Curie, 11 place Marcelin Berthelot, 75 231 Paris Cedex 05, France
| | - Laurent Aussel
- Aix Marseille Université, CNRS, Laboratoire de Chimie Bactérienne (LCB) UMR 7283, Institut de Microbiologie de la Méditerranée (IMM), 13402, Marseille, France
| | - Mahmoud Hajj Chehade
- University Grenoble Alpes, Laboratoire Technologies de l'Ingénierie Médicale et de la Complexité-Informatique, Mathématiques et Applications, Techniques de l'Ingénierie Médicale et de la Complexité-Informatique, Mathématiques et Applications, Grenoble (TIMC-IMAG), UMR 5525, 38000 Grenoble, France; CNRS, TIMC-IMAG, 38000 Grenoble, France
| | - Sara B Hernández
- Departamento de Genética, Universidad de Sevilla, 41012 Sevilla, Spain
| | - Bruno Faivre
- Laboratoire de Chimie des Processus Biologiques, UMR8229 CNRS, Collège de France, Université Pierre et Marie Curie, 11 place Marcelin Berthelot, 75 231 Paris Cedex 05, France
| | - Djemel Hamdane
- Laboratoire de Chimie des Processus Biologiques, UMR8229 CNRS, Collège de France, Université Pierre et Marie Curie, 11 place Marcelin Berthelot, 75 231 Paris Cedex 05, France
| | - Caroline Mellot-Draznieks
- Laboratoire de Chimie des Processus Biologiques, UMR8229 CNRS, Collège de France, Université Pierre et Marie Curie, 11 place Marcelin Berthelot, 75 231 Paris Cedex 05, France
| | - Bérengère Rascalou
- University Grenoble Alpes, Laboratoire Technologies de l'Ingénierie Médicale et de la Complexité-Informatique, Mathématiques et Applications, Techniques de l'Ingénierie Médicale et de la Complexité-Informatique, Mathématiques et Applications, Grenoble (TIMC-IMAG), UMR 5525, 38000 Grenoble, France; CNRS, TIMC-IMAG, 38000 Grenoble, France
| | - Ludovic Pelosi
- University Grenoble Alpes, Laboratoire Technologies de l'Ingénierie Médicale et de la Complexité-Informatique, Mathématiques et Applications, Techniques de l'Ingénierie Médicale et de la Complexité-Informatique, Mathématiques et Applications, Grenoble (TIMC-IMAG), UMR 5525, 38000 Grenoble, France; CNRS, TIMC-IMAG, 38000 Grenoble, France
| | - Christophe Velours
- Institut de Biologie Integrative de la cellule, Plateforme Interactions des Macromolécules, I2BC, UMR 9198 CNRS, Bât 430F, 91405 Orsay Cedex, France
| | - David Cornu
- Institut de Biologie Integrative de la cellule, Plateforme SICaPS, I2BC, CNRS, Centre de Recherche de Gif, SICaPS, F-91198 Gif-sur-Yvette Cedex, France
| | - Murielle Lombard
- Laboratoire de Chimie des Processus Biologiques, UMR8229 CNRS, Collège de France, Université Pierre et Marie Curie, 11 place Marcelin Berthelot, 75 231 Paris Cedex 05, France
| | - Josep Casadesús
- Departamento de Genética, Universidad de Sevilla, 41012 Sevilla, Spain
| | - Fabien Pierrel
- University Grenoble Alpes, Laboratoire Technologies de l'Ingénierie Médicale et de la Complexité-Informatique, Mathématiques et Applications, Techniques de l'Ingénierie Médicale et de la Complexité-Informatique, Mathématiques et Applications, Grenoble (TIMC-IMAG), UMR 5525, 38000 Grenoble, France; CNRS, TIMC-IMAG, 38000 Grenoble, France.
| | - Marc Fontecave
- Laboratoire de Chimie des Processus Biologiques, UMR8229 CNRS, Collège de France, Université Pierre et Marie Curie, 11 place Marcelin Berthelot, 75 231 Paris Cedex 05, France.
| | - Frédéric Barras
- Aix Marseille Université, CNRS, Laboratoire de Chimie Bactérienne (LCB) UMR 7283, Institut de Microbiologie de la Méditerranée (IMM), 13402, Marseille, France.
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21
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A structural appraisal of sterol carrier protein 2. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2017; 1865:565-577. [DOI: 10.1016/j.bbapap.2017.03.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 03/03/2017] [Accepted: 03/07/2017] [Indexed: 11/19/2022]
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22
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Martin GG, Landrock D, Landrock KK, Howles PN, Atshaves BP, Kier AB, Schroeder F. Relative contributions of L-FABP, SCP-2/SCP-x, or both to hepatic biliary phenotype of female mice. Arch Biochem Biophys 2015; 588:25-32. [PMID: 26541319 PMCID: PMC4683591 DOI: 10.1016/j.abb.2015.10.018] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Revised: 10/20/2015] [Accepted: 10/28/2015] [Indexed: 01/01/2023]
Abstract
Both sterol carrier protein-2/sterol carrier protein-x (SCP-2/SCP-x) and liver fatty acid binding protein (L-FABP) have been proposed to function in hepatobiliary bile acid metabolism/accumulation. To begin to address this issue, the impact of ablating L-FABP (LKO) or SCP-2/SCP-x (DKO) individually or both together (TKO) was examined in female mice. Biliary bile acid levels were decreased in LKO, DKO, and TKO mice; however, hepatic bile acid concentration was decreased in LKO mice only. In contrast, biliary phospholipid level was decreased only in TKO mice, while biliary cholesterol levels were unaltered regardless of phenotype. The loss of either or both genes increased hepatic expression of the major bile acid synthetic enzymes (CYP7A1 and/or CYP27A1). Loss of L-FABP and/or SCP-2/SCP-x genes significantly altered the molecular composition of biliary bile acids, but not the proportion of conjugated/unconjugated bile acids or overall bile acid hydrophobicity index. These data suggested that L-FABP was more important in hepatic retention of bile acids, while SCP-2/SCP-x more broadly affected biliary bile acid and phospholipid levels.
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Affiliation(s)
- Gregory G Martin
- Department of Physiology and Pharmacology, Texas A&M University, College Station, TX 77843-4466, USA
| | - Danilo Landrock
- Department of Pathobiology, Texas A&M University, College Station, TX 77843-4467, USA
| | - Kerstin K Landrock
- Department of Physiology and Pharmacology, Texas A&M University, College Station, TX 77843-4466, USA
| | - Philip N Howles
- Department of Pathology and Laboratory Medicine, University of Cincinnati, Cincinnati, OH 45219, USA
| | - Barbara P Atshaves
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
| | - Ann B Kier
- Department of Pathobiology, Texas A&M University, College Station, TX 77843-4467, USA
| | - Friedhelm Schroeder
- Department of Physiology and Pharmacology, Texas A&M University, College Station, TX 77843-4466, USA.
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23
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Martin GG, Atshaves BP, Landrock KK, Landrock D, Schroeder F, Kier AB. Loss of L-FABP, SCP-2/SCP-x, or both induces hepatic lipid accumulation in female mice. Arch Biochem Biophys 2015; 580:41-9. [PMID: 26116377 DOI: 10.1016/j.abb.2015.06.009] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2014] [Revised: 06/08/2015] [Accepted: 06/17/2015] [Indexed: 02/06/2023]
Abstract
Although roles for both sterol carrier protein-2/sterol carrier protein-x (SCP-2/SCP-x) and liver fatty acid binding protein (L-FABP) have been proposed in hepatic lipid accumulation, individually ablating these genes has been complicated by concomitant alterations in the other gene product(s). For example, ablating SCP2/SCP-x induces upregulation of L-FABP in female mice. Therefore, the impact of ablating SCP-2/SCP-x (DKO) or L-FABP (LKO) individually or both together (TKO) was examined in female mice. Loss of SCP-2/SCP-x (DKO, TKO) more so than loss of L-FABP alone (LKO) increased hepatic total lipid and total cholesterol content, especially cholesteryl ester. Hepatic accumulation of nonesterified long chain fatty acids (LCFA) and phospholipids occurred only in DKO and TKO mice. Loss of SCP-2/SCP-x (DKO, TKO) increased serum total lipid primarily by increasing triglycerides. Altered hepatic level of proteins involved in cholesterol uptake, efflux, and/or secretion was observed, but did not compensate for the loss of L-FABP, SCP-2/SCP-x or both. However, synergistic responses were not seen with the combinatorial knock out animals-suggesting that inhibiting SCP-2/SCP-x is more correlative with hepatic dysfunction than L-FABP. The DKO- and TKO-induced hepatic accumulation of cholesterol and long chain fatty acids shared significant phenotypic similarities with non-alcoholic fatty liver disease (NAFLD).
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Affiliation(s)
- Gregory G Martin
- Department of Physiology and Pharmacology, Texas A&M University, College Station, TX 77843-4466, United States
| | - Barbara P Atshaves
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, United States
| | - Kerstin K Landrock
- Department of Pathobiology, Texas A&M University, College Station, TX 77843-4467, United States
| | - Danilo Landrock
- Department of Pathobiology, Texas A&M University, College Station, TX 77843-4467, United States
| | - Friedhelm Schroeder
- Department of Physiology and Pharmacology, Texas A&M University, College Station, TX 77843-4466, United States
| | - Ann B Kier
- Department of Pathobiology, Texas A&M University, College Station, TX 77843-4467, United States.
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24
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Curto LM, Angelani CR, Delfino JM. Intervening in the β-barrel structure of lipid binding proteins: consequences on folding, ligand-binding and aggregation propensity. Prostaglandins Leukot Essent Fatty Acids 2015; 93:37-43. [PMID: 25242388 DOI: 10.1016/j.plefa.2014.08.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Revised: 07/26/2014] [Accepted: 08/01/2014] [Indexed: 02/02/2023]
Abstract
Natural β-folds manage to fold up successfully. By contrast, attempts to dissect fragments or peptides from well folded β-sheet proteins have met with insurmountable difficulties. Here we briefly review selected successful cases of intervention on the well-known scaffold of intestinal fatty acid binding protein (IFABP). Lessons from these examples might set guidelines along the design of proteins belonging to this class. Impact of modifications on topology, binding and aggregation is highlighted. With the aid of abridged variants of IFABP we focus on key structural features responsible for the assembly into oligomeric forms or aggregates.
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Affiliation(s)
- L M Curto
- Department of Biological Chemistry and Institute of Biochemistry and Biophysics (IQUIFIB), School of Pharmacy and Biochemistry, University of Buenos Aires, Junín 956, C1113AAD Buenos Aires, Argentina
| | - C R Angelani
- Department of Biological Chemistry and Institute of Biochemistry and Biophysics (IQUIFIB), School of Pharmacy and Biochemistry, University of Buenos Aires, Junín 956, C1113AAD Buenos Aires, Argentina
| | - J M Delfino
- Department of Biological Chemistry and Institute of Biochemistry and Biophysics (IQUIFIB), School of Pharmacy and Biochemistry, University of Buenos Aires, Junín 956, C1113AAD Buenos Aires, Argentina.
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Martin GG, Atshaves BP, Landrock KK, Landrock D, Storey SM, Howles PN, Kier AB, Schroeder F. Ablating L-FABP in SCP-2/SCP-x null mice impairs bile acid metabolism and biliary HDL-cholesterol secretion. Am J Physiol Gastrointest Liver Physiol 2014; 307:G1130-43. [PMID: 25277800 PMCID: PMC4254959 DOI: 10.1152/ajpgi.00209.2014] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Accepted: 09/28/2014] [Indexed: 01/31/2023]
Abstract
On the basis of their abilities to bind bile acids and/or cholesterol, the physiological role(s) of liver fatty acid-binding protein (L-FABP) and sterol carrier protein (SCP) 2/SCP-x (SCP-2/SCP-x) gene products in biliary bile acid and cholesterol formation was examined in gene-ablated male mice. L-FABP (LKO) or L-FABP/SCP-2/SCP-x [triple-knockout (TKO)] ablation markedly decreased hepatic bile acid concentration, while SCP-2/SCP-x [double-knockout (DKO)] ablation alone had no effect. In contrast, LKO increased biliary bile acid, while DKO and TKO had no effect on biliary bile acid levels. LKO and DKO also altered biliary bile acid composition to increase bile acid hydrophobicity. Furthermore, LKO and TKO decreased hepatic uptake and biliary secretion of high-density lipoprotein (HDL)-derived 22-(N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino)-23,24-bisnor-5-cholen-3β-ol (NBD-cholesterol), while DKO alone had no effect. Finally, LKO and, to a lesser extent, DKO decreased most indexes contributing to cholesterol solubility in biliary bile. These results suggest different, but complementary, roles for L-FABP and SCP-2/SCP-x in biliary bile acid and cholesterol formation. L-FABP appears to function more in hepatic retention of bile acids as well as hepatic uptake and biliary secretion of HDL-cholesterol. Conversely, SCP-2/SCP-x may function more in formation and biliary secretion of bile acid, with less impact on hepatic uptake or biliary secretion of HDL-cholesterol.
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Affiliation(s)
- Gregory G Martin
- Department of Physiology and Pharmacology, Texas A & M University, College Station, Texas
| | - Barbara P Atshaves
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan
| | - Kerstin K Landrock
- Department of Pathobiology, Texas A & M University, College Station, Texas; and
| | - Danilo Landrock
- Department of Pathobiology, Texas A & M University, College Station, Texas; and
| | - Stephen M Storey
- Department of Physiology and Pharmacology, Texas A & M University, College Station, Texas
| | - Philip N Howles
- Department of Pathology and Laboratory Medicine, University of Cincinnati, Cincinnati, Ohio
| | - Ann B Kier
- Department of Pathobiology, Texas A & M University, College Station, Texas; and
| | - Friedhelm Schroeder
- Department of Physiology and Pharmacology, Texas A & M University, College Station, Texas;
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De Berti FP, Capaldi S, Ferreyra R, Burgardt N, Acierno JP, Klinke S, Monaco HL, Ermácora MR. The crystal structure of sterol carrier protein 2 from Yarrowia lipolytica and the evolutionary conservation of a large, non-specific lipid-binding cavity. ACTA ACUST UNITED AC 2013; 14:145-53. [DOI: 10.1007/s10969-013-9166-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2013] [Accepted: 11/11/2013] [Indexed: 11/25/2022]
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Murdoch RW, Hay AG. Genetic and chemical characterization of ibuprofen degradation by Sphingomonas Ibu-2. MICROBIOLOGY (READING, ENGLAND) 2013; 159:621-632. [PMID: 23329679 PMCID: PMC4083657 DOI: 10.1099/mic.0.062273-0] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2012] [Revised: 11/05/2012] [Accepted: 01/14/2013] [Indexed: 01/03/2023]
Abstract
Sphingomonas Ibu-2 has the unusual ability to cleave the acid side chain from the pharmaceutical ibuprofen and related arylacetic acid derivatives to yield corresponding catechols under aerobic conditions via a previously uncharacterized mechanism. Screening a chromosomal library of Ibu-2 DNA in Escherichia coli EPI300 allowed us to identify one fosmid clone (pFOS3G7) that conferred the ability to metabolize ibuprofen to isobutylcatechol. Characterization of pFOS3G7 loss-of-function transposon mutants permitted identification of five ORFs, ipfABDEF, whose predicted amino acid sequences bore similarity to the large and small units of an aromatic dioxygenase (ipfAB), a sterol carrier protein X (SCPx) thiolase (ipfD), a domain of unknown function 35 (DUF35) protein (ipfE) and an aromatic CoA ligase (ipfF). Two additional ORFs, ipfH and ipfI, which encode putative ferredoxin reductase and ferredoxin components of an aromatic dioxygenase system, respectively, were also identified on pFOS3G7. Complementation of a markerless loss-of-function ipfD deletion mutant restored catechol production as did complementation of the ipfF Tn mutant. Expression of subcloned ipfABDEF alone in E. coli did not impart full metabolic activity unless coexpressed with ipfHI. CoA ligation followed by ring oxidation is common to phenylacetic acid pathways. However, the need for a putative SCPx thiolase (IpfD) and DUF35 protein (IpfE) in aerobic arylacetic acid degradation is unprecedented. This work provides preliminary insights into the mechanism behind this novel arylacetic acid-deacylating, catechol-generating activity.
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Affiliation(s)
- Robert W. Murdoch
- Graduate Program in Environmental Toxicology, Institute for Comparative and Environmental Toxicology, Cornell University, Ithaca, NY 14850, USA
| | - Anthony G. Hay
- Graduate Program in Environmental Toxicology, Institute for Comparative and Environmental Toxicology, Cornell University, Ithaca, NY 14850, USA
- Department of Microbiology, B53A Wing Hall, Cornell University, Ithaca, NY 14850, USA
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Faust JE, Verma A, Peng C, McNew JA. An inventory of peroxisomal proteins and pathways in Drosophila melanogaster. Traffic 2012; 13:1378-92. [PMID: 22758915 PMCID: PMC3443258 DOI: 10.1111/j.1600-0854.2012.01393.x] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2011] [Revised: 06/28/2012] [Accepted: 07/03/2012] [Indexed: 11/29/2022]
Abstract
Peroxisomes are ubiquitous organelles housing a variety of essential biochemical pathways. Peroxisome dysfunction causes a spectrum of human diseases known as peroxisome biogenesis disorders (PBD). Although much is known regarding the mechanism of peroxisome biogenesis, it is still unclear how peroxisome dysfunction leads to the disease state. Several recent studies have shown that mutations in Drosophila peroxin genes cause phenotypes similar to those seen in humans with PBDs suggesting that Drosophila might be a useful system to model PBDs. We have analyzed the proteome of Drosophila to identify the proteins involved in peroxisomal biogenesis and homeostasis as well as metabolic enzymes that function within the organelle. The subcellular localization of five of these predicted peroxisomal proteins was confirmed. Similar to Caenorhabditis elegans, Drosophila appears to only utilize the peroxisome targeting signal type 1 system for matrix protein import. This work will further our understanding of peroxisomes in Drosophila and add to the usefulness of this emerging model system.
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Affiliation(s)
- Joseph E. Faust
- Department of Biochemistry and Cell Biology, Rice University, 6100 Main Street MS601, Houston, TX 77005
| | - Avani Verma
- Department of Biochemistry and Cell Biology, Rice University, 6100 Main Street MS601, Houston, TX 77005
| | - Chengwei Peng
- Department of Biochemistry and Cell Biology, Rice University, 6100 Main Street MS601, Houston, TX 77005
| | - James A. McNew
- Department of Biochemistry and Cell Biology, Rice University, 6100 Main Street MS601, Houston, TX 77005
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McIntosh AL, Atshaves BP, Storey SM, Landrock KK, Landrock D, Martin GG, Kier AB, Schroeder F. Loss of liver FA binding protein significantly alters hepatocyte plasma membrane microdomains. J Lipid Res 2012; 53:467-480. [PMID: 22223861 PMCID: PMC3276470 DOI: 10.1194/jlr.m019919] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2011] [Revised: 12/21/2011] [Indexed: 12/13/2022] Open
Abstract
Although lipid-rich microdomains of hepatocyte plasma membranes serve as the major scaffolding regions for cholesterol transport proteins important in cholesterol disposition, little is known regarding intracellular factors regulating cholesterol distribution therein. On the basis of its ability to bind cholesterol and alter hepatic cholesterol accumulation, the cytosolic liver type FA binding protein (L-FABP) was hypothesized to be a candidate protein regulating these microdomains. Compared with wild-type hepatocyte plasma membranes, L-FABP gene ablation significantly increased the proportion of cholesterol-rich microdomains. Lack of L-FABP selectively increased cholesterol, phospholipid (especially phosphatidylcholine), and branched-chain FA accumulation in the cholesterol-rich microdomains. These cholesterol-rich microdomains are important, owing to enrichment therein of significant amounts of key transport proteins involved in uptake of cholesterol [SR-B1, ABCA-1, P-glycoprotein (P-gp), sterol carrier binding protein (SCP-2)], FA transport protein (FATP), and glucose transporters 1 and 2 (GLUT1, GLUT2) insulin receptor. L-FABP gene ablation enhanced the concentration of SCP-2, SR-B1, FATP4, and GLUT1 in the cholesterol-poor microdomains, with functional implications in HDL-mediated uptake and efflux of cholesterol. Thus L-FABP gene ablation significantly impacted the proportion of cholesterol-rich versus -poor microdomains in the hepatocyte plasma membrane and altered the distribution of lipids and proteins involved in cholesterol uptake therein.
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Affiliation(s)
- Avery L McIntosh
- Department of Physiology and Pharmacology, Texas A&M University Texas Veterinary Medical Center, College Station, TX 77843; and
| | - Barbara P Atshaves
- Department of Biochemistry & Molecular Biology, Michigan State University, East Lansing, MI 48824
| | - Stephen M Storey
- Department of Physiology and Pharmacology, Texas A&M University Texas Veterinary Medical Center, College Station, TX 77843; and
| | - Kerstin K Landrock
- Department of Physiology and Pharmacology, Texas A&M University Texas Veterinary Medical Center, College Station, TX 77843; and
| | - Danilo Landrock
- Department of Pathobiology, Texas A&M University Texas Veterinary Medical Center, College Station, TX 77843; and
| | - Gregory G Martin
- Department of Physiology and Pharmacology, Texas A&M University Texas Veterinary Medical Center, College Station, TX 77843; and
| | - Ann B Kier
- Department of Pathobiology, Texas A&M University Texas Veterinary Medical Center, College Station, TX 77843; and
| | - Friedhelm Schroeder
- Department of Physiology and Pharmacology, Texas A&M University Texas Veterinary Medical Center, College Station, TX 77843; and.
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The characterization and evolutionary relationships of a trypanosomal thiolase. Int J Parasitol 2011; 41:1273-83. [DOI: 10.1016/j.ijpara.2011.07.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2011] [Revised: 06/22/2011] [Accepted: 07/19/2011] [Indexed: 11/23/2022]
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Cui Y, Li Z, Zhao E, Jia Y, Li D, Zhang J, Cui N. Overexpression of Sterol Carrier Protein 2 in patients with hereditary cholesterol gallstones. BMC Gastroenterol 2011; 11:10. [PMID: 21310066 PMCID: PMC3042972 DOI: 10.1186/1471-230x-11-10] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2010] [Accepted: 02/10/2011] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND Lithogenic bile is the major cause of cholesterol gallstone, but its pathogenesis is not well understood. The hypersecretion of biliary cholesterol is believed to be an important cause of lithogenic bile. Sterol Carrier Protein 2 (SCP2) participates in cholesterol trafficking and lipid metabolism in hepatocytes and may play a key role in cholesterol gallstone formation. METHODS 21 cholesterol gallstone genealogies were studied to investigate the expression of SCP2 gene in liver tissue of hereditary and non-hereditary cholesterol gallstone patients as well as non-gallstone patients. The mRNA expression of liver SCP2 in 28 hereditary patients, 30 non-hereditary cholesterol gallstone patients and 32 non-gallstone patients was measured by Reverse Transcription Polymerase Chain Reaction (RT-PCR). The protein expression of liver SCP2 was also detected in all the patients by Western blotting. At the same time, the bile was also analyzed with biochemical techniques and the Cholesterol Saturation Index (CSI) was calculated. RESULTS The mRNA and protein expression of SCP2 was significantly increased in cholesterol gallstone patients compared to those of non-gallstone patients. Moreover, SCP2 was expressed at higher levels in hereditary cholesterol gallstone patients than that of non-hereditary cholesterol gallstone patients. There was significant difference observed in CSI between cholesterol gallstone patients and non-gallstone patients, but not in CSI between hereditary and non-hereditary cholesterol gallstone patients. CONCLUSIONS SCP2 was overexpressed in hereditary cholesterol gallstone patients compared to non-hereditary cholesterol gallstone patients. This finding indicated that SCP2 might be one of the genetic factors contributing to cholesterol gallstone formation, which was always accompanied by the increase of bile lithogenicity.
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Affiliation(s)
- YunFeng Cui
- Department of Surgery, Tianjin Nankai Hospital, Nankai Clinical School of Medicine, Tianjin Medical University, 122 Sanwei Road Nankai District, Tianjin 300100, PR China
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Atshaves B, Martin G, Hostetler H, McIntosh A, Kier A, Schroeder F. Liver fatty acid-binding protein and obesity. J Nutr Biochem 2010; 21:1015-32. [PMID: 20537520 PMCID: PMC2939181 DOI: 10.1016/j.jnutbio.2010.01.005] [Citation(s) in RCA: 159] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2009] [Revised: 01/11/2010] [Accepted: 01/12/2010] [Indexed: 12/17/2022]
Abstract
While low levels of unesterified long chain fatty acids (LCFAs) are normal metabolic intermediates of dietary and endogenous fat, LCFAs are also potent regulators of key receptors/enzymes and at high levels become toxic detergents within the cell. Elevated levels of LCFAs are associated with diabetes, obesity and metabolic syndrome. Consequently, mammals evolved fatty acid-binding proteins (FABPs) that bind/sequester these potentially toxic free fatty acids in the cytosol and present them for rapid removal in oxidative (mitochondria, peroxisomes) or storage (endoplasmic reticulum, lipid droplets) organelles. Mammals have a large (15-member) family of FABPs with multiple members occurring within a single cell type. The first described FABP, liver-FABP (L-FABP or FABP1), is expressed in very high levels (2-5% of cytosolic protein) in liver as well as in intestine and kidney. Since L-FABP facilitates uptake and metabolism of LCFAs in vitro and in cultured cells, it was expected that abnormal function or loss of L-FABP would reduce hepatic LCFA uptake/oxidation and thereby increase LCFAs available for oxidation in muscle and/or storage in adipose. This prediction was confirmed in vitro with isolated liver slices and cultured primary hepatocytes from L-FABP gene-ablated mice. Despite unaltered food consumption when fed a control diet ad libitum, the L-FABP null mice exhibited age- and sex-dependent weight gain and increased fat tissue mass. The obese phenotype was exacerbated in L-FABP null mice pair fed a high-fat diet. Taken together with other findings, these data suggest that L-FABP could have an important role in preventing age- or diet-induced obesity.
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Affiliation(s)
- B.P. Atshaves
- Department of Physiology and Pharmacology, Texas A&M University, TVMC, College Station, TX 77843-4466
| | - G.G. Martin
- Department of Physiology and Pharmacology, Texas A&M University, TVMC, College Station, TX 77843-4466
| | - H.A. Hostetler
- Department of Physiology and Pharmacology, Texas A&M University, TVMC, College Station, TX 77843-4466
| | - A.L. McIntosh
- Department of Physiology and Pharmacology, Texas A&M University, TVMC, College Station, TX 77843-4466
| | - A.B. Kier
- Department of Pathobiology, Texas A&M University, TVMC, College Station, TX 77843-4467
| | - F. Schroeder
- Department of Physiology and Pharmacology, Texas A&M University, TVMC, College Station, TX 77843-4466
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NMR and X-ray structures of the putative sterol carrier protein 2 from Thermus thermophilus HB8 show conformational changes. ACTA ACUST UNITED AC 2010; 11:247-56. [DOI: 10.1007/s10969-010-9096-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2010] [Accepted: 09/23/2010] [Indexed: 11/27/2022]
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Kriska T, Pilat A, Schmitt JC, Girotti AW. Sterol carrier protein-2 (SCP-2) involvement in cholesterol hydroperoxide cytotoxicity as revealed by SCP-2 inhibitor effects. J Lipid Res 2010; 51:3174-84. [PMID: 20656919 DOI: 10.1194/jlr.m008342] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Sterol carrier protein-2 (SCP-2) plays an important role in cholesterol trafficking and metabolism in mammalian cells. The purpose of this study was to determine whether SCP-2, under oxidative stress conditions, might also traffic hydroperoxides of cholesterol, thereby disseminating their cytotoxic effects. Two inhibitors, SCPI-1 and SCPI-3, known to block cholesterol binding by an insect SCP-2, were used to investigate this. A mouse fibroblast transfectant clone (SC2F) overexpressing SCP-2 was found to be substantially more sensitive to apoptotic killing induced by liposomal 7α-hydroperoxycholesterol (7α-OOH) than a wild-type control. 7α-OOH uptake by SC2F cells and resulting apoptosis were both inhibited by SCPI-1 or SCPI-3 at a subtoxic concentration. Preceding cell death, reactive oxidant accumulation and loss of mitochondrial membrane potential were also strongly inhibited. Similar SCPI protection against 7α-OOH was observed with two other types of SCP-2-expressing mammalian cells. In striking contrast, neither inhibitor had any effect on H(2)O(2)-induced cell killing. To learn whether 7α-OOH cytotoxicity is due to uptake/transport by SCP-2, we used a fluorescence-based competitive binding assay involving recombinant SCP-2, NBD-cholesterol, and SCPI-1/SCPI-3 or 7α-OOH. The results clearly showed that 7α-OOH binds to SCP-2 in SCPI-inhibitable fashion. Our findings suggest that cellular SCP-2 not only binds and translocates cholesterol but also cholesterol hydroperoxides, thus expanding their redox toxicity and signaling ranges under oxidative stress conditions.
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Affiliation(s)
- Tamas Kriska
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI, USA
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Iga M, Smagghe G. Identification and expression profile of Halloween genes involved in ecdysteroid biosynthesis in Spodoptera littoralis. Peptides 2010; 31:456-67. [PMID: 19682519 DOI: 10.1016/j.peptides.2009.08.002] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2009] [Revised: 08/03/2009] [Accepted: 08/03/2009] [Indexed: 10/20/2022]
Abstract
20-Hydroxyecdyone (20E), an active form of ecdysteroid, is the key hormone in insect growth and development. The biosynthesis of ecdysteroid is triggered and under the control of the neuropeptide, prothoracicotropic hormone (PTTH). To date, five cytochrome P450 enzymes, namely Spook (Spo), Phantom (Phm), Disembodied (Dib), Shadow (Sad) and Shade (Shd) related to ecdysteroid biosynthesis, are identified and the character of last four enzymes is well studied in Drosophila melanogaster, Bombyx mori and Manduca sexta. These genes are called Halloween genes and mediate the biosynthesis of 20E from cholesterol. In this study, we extended these works to a major pest insect in agriculture, the cotton leafworm Spodoptera littoralis (Lepidoptera: Noctuidae). We identified the sequence of five Halloween genes, and the converted amino acid sequences were compared with those of other insects. The phylogenetic analysis clearly showed separated clusters of each gene and the evolutional conservation in insects with a high similarity in Lepidoptera. Spo, phm, dib and sad were predominantly expressed in prothoracic glands, and shd was expressed in fat body and Malpighian tubules at the last instar larvae. Spo expression was kept high level between day 2 and day 4 after ecdysis. The expression of phm and dib peaked at day 2, and sad and shd expressions peaked at day 2 and day 4 after ecdysis. In addition, the hemolymph ecdysteroid titer showed a small peak at day 2 and a large peak at day 4 after ecdysis. These results suggest the importance of Halloween genes in ecdysone biosynthesis by prothoracic glands and conversion of ecdysone into 20E by fat body in larval-pupal metamorphosis.
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Affiliation(s)
- Masatoshi Iga
- Laboratory of Agrozoology, Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, B-9000 Ghent, Belgium.
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Schroeder F, Huang H, McIntosh AL, Atshaves BP, Martin GG, Kier AB. Caveolin, sterol carrier protein-2, membrane cholesterol-rich microdomains and intracellular cholesterol trafficking. Subcell Biochem 2010; 51:279-318. [PMID: 20213548 DOI: 10.1007/978-90-481-8622-8_10] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
While the existence of membrane lateral microdomains has been known for over 30 years, interest in these structures accelerated in the past decade due to the discovery that cholesterol-rich microdomains serve important biological functions. It is increasingly appreciated that cholesterol-rich microdomains in the plasma membranes of eukaryotic cells represent an organizing nexus for multiple cellular proteins involved in transmembrane nutrient uptake (cholesterol, fatty acid, glucose, etc.), cell-signaling, immune recognition, pathogen entry, and many other roles. Despite these advances, however, relatively little is known regarding the organization of cholesterol itself in these plasma membrane microdomains. Although a variety of non-sterol markers indicate the presence of microdomains in the plasma membranes of living cells, none of these studies have demonstrated that cholesterol is enriched in these microdomains in living cells. Further, the role of cholesterol-rich membrane microdomains as targets for intracellular cholesterol trafficking proteins such as sterol carrier protein-2 (SCP-2) that facilitate cholesterol uptake and transcellular transport for targeting storage (cholesterol esters) or efflux is only beginning to be understood. Herein, we summarize the background as well as recent progress in this field that has advanced our understanding of these issues.
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Affiliation(s)
- Friedhelm Schroeder
- Department of Physiology and Pharmacology, Texas A&M University, TVMC College Station, TX, 77843-4466, USA.
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Burgardt NI, Ferreyra RG, Falomir-Lockhart L, Córsico B, Ermácora MR, Ceolín M. Biophysical characterisation and urea-induced unfolding of recombinant Yarrowia lipolytica sterol carrier protein-2. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2009; 1794:1115-22. [PMID: 19376277 DOI: 10.1016/j.bbapap.2009.04.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2008] [Revised: 03/18/2009] [Accepted: 04/06/2009] [Indexed: 11/30/2022]
Affiliation(s)
- Noelia I Burgardt
- Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Bernal, Argentina
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Gong J, Hou Y, Zha XF, Lu C, Zhu Y, Xia QY. Molecular cloning and characterization ofBombyx moristerol carrier protein x/sterol carrier protein 2 (SCPx/SCP2) gene. ACTA ACUST UNITED AC 2009; 17:326-33. [PMID: 17343205 DOI: 10.1080/10425170600886706] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Cholesterol transport is a very important process in insect. We have isolated the Bombyx mori sterol carrier protein x (BmSCPx) cDNA and sterol carrier protein 2 (BmSCP2) cDNA: a 1.7 kb clone encoding SCPx, a 3-ketoacyl CoA thiolase, and 0.6 kb clone presumably encoding SCP2, which is thought to be an intracellular lipid transfer protein. Interestingly, the identical gene SCPx/SCP2 encodes the two types of transcripts by alternative splicing mechanism in Bombyx mori. The SCPx mRNA spans two exons in genome, and conceptual translation of the SCPx cDNA encodes a protein of 536 amino acids, which contains a thiolase domain and a SCP2 domain. Whereas the SCP2 mRNA partly lakes the first exon, and the SCP2 is a 146 amino acids containing a SCP2 domain only. Both BmSCPx and BmSCP2 have a putative peroxisomal targeting signal in the C-terminal region. BmSCPx shares 94 and 72% similarity to Spodoptera littoralis SCPx and human SCPx, respectively. RT-PCR analysis reveals that transcripts of BmSCP2 were detected in all tissues analyzed. BmSCPx transcription expressed only in midgut and malpighian tubules. However, the BmSCPx and BmSCP2 express strong in midgut during the last instar larvae. The tissue-specific expression pattern of BmSCPx and BmSCP2 is consistent with a role for these proteins in cholesterol metabolism. The results suggest that SCPx/SCP2 may play a key role in sterol absorption and intracellular carrier in silkworm.
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Affiliation(s)
- Jing Gong
- Key Sericultural Laboratory of Agricultural Ministry, Southwest University, Chongqing 400715, People's Republic of China
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Huang X, Warren JT, Gilbert LI. New players in the regulation of ecdysone biosynthesis. J Genet Genomics 2009; 35:1-10. [PMID: 18222403 DOI: 10.1016/s1673-8527(08)60001-6] [Citation(s) in RCA: 101] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2007] [Revised: 11/24/2007] [Accepted: 11/24/2007] [Indexed: 02/04/2023]
Abstract
Insect ecdysone steroid hormone regulates major developmental transitions, such as molting and metamorphosis. The production of ecdysone correlates well with the timing of these transitions. Finding out how the ecdysone biosynthesis is regulated is crucial to fully understand these sophisticated developmental switches. Here we summarized recent findings in the regulation of ecdysone biosynthesis from the aspects of cell signaling, key biosynthetic enzymes and substrate cholesterol trafficking.
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Affiliation(s)
- Xun Huang
- Laboratory of Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.
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40
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McIntosh AL, Atshaves BP, Huang H, Gallegos AM, Kier AB, Schroeder F. Fluorescence techniques using dehydroergosterol to study cholesterol trafficking. Lipids 2008; 43:1185-208. [PMID: 18536950 PMCID: PMC2606672 DOI: 10.1007/s11745-008-3194-1] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2008] [Accepted: 05/09/2008] [Indexed: 12/22/2022]
Abstract
Cholesterol itself has very few structural/chemical features suitable for real-time imaging in living cells. Thus, the advent of dehydroergosterol [ergosta-5,7,9(11),22-tetraen-3beta-ol, DHE] the fluorescent sterol most structurally and functionally similar to cholesterol to date, has proven to be a major asset for real-time probing/elucidating the sterol environment and intracellular sterol trafficking in living organisms. DHE is a naturally occurring, fluorescent sterol analog that faithfully mimics many of the properties of cholesterol. Because these properties are very sensitive to sterol structure and degradation, such studies require the use of extremely pure (>98%) quantities of fluorescent sterol. DHE is readily bound by cholesterol-binding proteins, is incorporated into lipoproteins (from the diet of animals or by exchange in vitro), and for real-time imaging studies is easily incorporated into cultured cells where it co-distributes with endogenous sterol. Incorporation from an ethanolic stock solution to cell culture media is effective, but this process forms an aqueous dispersion of DHE crystals which can result in endocytic cellular uptake and distribution into lysosomes which is problematic in imaging DHE at the plasma membrane of living cells. In contrast, monomeric DHE can be incorporated from unilamellar vesicles by exchange/fusion with the plasma membrane or from DHE-methyl-beta-cyclodextrin (DHE-MbetaCD) complexes by exchange with the plasma membrane. Both of the latter techniques can deliver large quantities of monomeric DHE with significant distribution into the plasma membrane. The properties and behavior of DHE in protein-binding, lipoproteins, model membranes, biological membranes, lipid rafts/caveolae, and real-time imaging in living cells indicate that this naturally occurring fluorescent sterol is a useful mimic for probing the properties of cholesterol in these systems.
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Affiliation(s)
- Avery L. McIntosh
- Department of Physiology and Pharmacology Texas A&M University, TVMC College Station, TX 77843-4466
| | - Barbara P. Atshaves
- Department of Physiology and Pharmacology Texas A&M University, TVMC College Station, TX 77843-4466
| | - Huan Huang
- Department of Physiology and Pharmacology Texas A&M University, TVMC College Station, TX 77843-4466
| | - Adalberto M. Gallegos
- Department of Pathobiology Texas A&M University, TVMC College Station, TX 77843-4467
| | - Ann B. Kier
- Department of Pathobiology Texas A&M University, TVMC College Station, TX 77843-4467
| | - Friedhelm Schroeder
- Department of Physiology and Pharmacology Texas A&M University, TVMC College Station, TX 77843-4466
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41
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McIntosh AL, Atshaves BP, Gallegos AM, Storey SM, Reibenspies JH, Kier AB, Meyer E, Schroeder F. Structure of dehydroergosterol monohydrate and interaction with sterol carrier protein-2. Lipids 2008; 43:1165-84. [PMID: 19020914 DOI: 10.1007/s11745-008-3267-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2008] [Accepted: 10/31/2008] [Indexed: 10/21/2022]
Abstract
Dehydroergosterol [ergosta-5,7,9(11),22-tetraen-3beta-ol] is a naturally-occurring, fluorescent sterol utilized extensively to probe membrane cholesterol distribution, cholesterol-protein interactions, and intracellular cholesterol transport both in vitro and in vivo. In aqueous solutions, the low solubility of dehydroergosterol results in the formation of monohydrate crystals similar to cholesterol. Low temperature X-ray diffraction analysis reveals that dehydroergosterol monohydrate crystallizes in the space group P2(1) with four molecules in the unit cell and monoclinic crystal parameters a = 9.975(1) A, b = 7.4731(9) A, c = 34.054(4) A, and beta = 92.970(2) degrees somewhat similar to ergosterol monohydrate. The molecular arrangement is in a slightly closer packed bilayer structure resembling cholesterol monohydrate. Since dehydroergosterol fluorescence emission undergoes a quantum yield enhancement and red-shift of its maximum wavelength when crystallized, formation or disruption of microcrystals was monitored with high sensitivity using cuvette-based spectroscopy and multi-photon laser scanning imaging microscopy. This manuscript reports on the dynamical effect of sterol carrier protein-2 (SCP-2) interacting between aqueous dispersions of dehydroergosterol monohydrate microcrystal donors and acceptors consisting not only of model membranes but also vesicles derived from plasma membranes isolated by biochemical fractionation and affinity purification from Madin-Darby canine kidney cells. Furthermore, this study provides real-time measurements of the effect of increased SCP-2 levels on the rate of disappearance of dehydroergosterol microcrystals in living cells.
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Affiliation(s)
- Avery L McIntosh
- Department of Physiology and Pharmacology, Texas A&M University, TVMC, College Station, TX 77843-4466, USA
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42
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Lige B, Jayabalasingham B, Zhang H, Pypaert M, Coppens I. Role of an ancestral d-bifunctional protein containing two sterol-carrier protein-2 domains in lipid uptake and trafficking in Toxoplasma. Mol Biol Cell 2008; 20:658-72. [PMID: 19005217 DOI: 10.1091/mbc.e08-05-0482] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The inability to synthesize cholesterol is universal among protozoa. The intracellular pathogen Toxoplasma depends on host lipoprotein-derived cholesterol to replicate in mammalian cells. Mechanisms of cholesterol trafficking in this parasite must be important for delivery to proper organelles. We characterized a unique d-bifunctional protein variant expressed by Toxoplasma consisting of one N-terminal d-3-hydroxyacyl-CoA dehydrogenase domain fused to two tandem sterol carrier protein-2 (SCP-2) domains. This multidomain protein undergoes multiple cleavage steps to release free SCP-2. The most C-terminal SCP-2 carries a PTS1 that directs the protein to vesicles before processing. Abrogation of this signal results in SCP-2 accumulation in the cytoplasm. Cholesterol specifically binds to parasite SCP-2 but with 10-fold lower affinity than phosphatidylcholine. In mammalian cells and Toxoplasma, the two parasite SCP-2 domains promote the circulation of various lipids between organelles and to the surface. Compared with wild-type parasites, TgHAD-2SCP-2-transfected parasites replicate faster and show enhanced uptake of cholesterol and oleate, which are incorporated into neutral lipids that accumulate at the basal end of Toxoplasma. This work provides the first evidence that the lipid transfer capability of an ancestral eukaryotic SCP-2 domain can influence the lipid metabolism of an intracellular pathogen to promote its multiplication in mammalian cells.
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Affiliation(s)
- Bao Lige
- Department of Molecular Microbiology and Immunology, Johns Hopkins University School of Public Health, Baltimore, MD 21205, USA
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43
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Martin GG, Hostetler HA, McIntosh AL, Tichy SE, Williams BJ, Russell DH, Berg JM, Spencer TA, Ball J, Kier AB, Schroeder F. Structure and function of the sterol carrier protein-2 N-terminal presequence. Biochemistry 2008; 47:5915-34. [PMID: 18465878 PMCID: PMC2474712 DOI: 10.1021/bi800251e] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Although sterol carrier protein-2 (SCP-2) is encoded as a precursor protein (proSCP-2), little is known regarding the structure and function of the 20-amino acid N-terminal presequence. As shown herein, the presequence contains significant secondary structure and alters SCP-2: (i) secondary structure (CD), (ii) tertiary structure (aqueous exposure of Trp shown by UV absorbance, fluorescence, and fluorescence quenching), (iii) ligand binding site [Trp response to ligands, peptide cross-linked by photoactivatable free cholesterol (FCBP)], (iv) selectivity for interaction with anionic phospholipid-rich membranes, (v) interaction with a peroxisomal import protein [FRET studies of Pex5p(C) binding], the N-terminal presequence increased SCP-2's affinity for Pex5p(C) by 10-fold, and (vi) intracellular targeting in living and fixed cells (confocal microscopy). Nearly 5-fold more SCP-2 than proSCP-2 colocalized with plasma membrane lipid rafts and caveolae (AF488-CTB); 2.8-fold more SCP-2 than proSCP-2 colocalized with a mitochondrial marker (Mitotracker), but nearly 2-fold less SCP-2 than proSCP-2 colocalized with peroxisomes (AF488 antibody to PMP70). These data indicate the importance of the N-terminal presequence in regulating SCP-2 structure, cholesterol localization within the ligand binding site, membrane association, and, potentially, intracellular targeting.
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Affiliation(s)
- Gregory G. Martin
- Department of Physiology and Pharmacology, Texas A&M University, TVMC, College Station, TX 77843-4466
| | - Heather A. Hostetler
- Department of Physiology and Pharmacology, Texas A&M University, TVMC, College Station, TX 77843-4466
| | - Avery L. McIntosh
- Department of Physiology and Pharmacology, Texas A&M University, TVMC, College Station, TX 77843-4466
| | - Shane E. Tichy
- Department of Chemistry, Texas A&M University, College Station, TX 77843-3255
| | - Brad J. Williams
- Department of Chemistry, Texas A&M University, College Station, TX 77843-3255
| | - David H. Russell
- Department of Chemistry, Texas A&M University, College Station, TX 77843-3255
| | - Jeremy M. Berg
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892
| | | | - Judith Ball
- Department of Pathobiology, Texas A&M University, College Station, TX 77843-4467
| | - Ann B. Kier
- Department of Pathobiology, Texas A&M University, College Station, TX 77843-4467
| | - Friedhelm Schroeder
- Department of Physiology and Pharmacology, Texas A&M University, TVMC, College Station, TX 77843-4466
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44
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Girotti AW. Translocation as a means of disseminating lipid hydroperoxide-induced oxidative damage and effector action. Free Radic Biol Med 2008; 44:956-68. [PMID: 18206663 PMCID: PMC2361152 DOI: 10.1016/j.freeradbiomed.2007.12.004] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2007] [Revised: 12/06/2007] [Accepted: 12/06/2007] [Indexed: 11/25/2022]
Abstract
Lipid hydroperoxides (LOOHs) generated in cells and lipoproteins under oxidative pressure may induce waves of damaging chain lipid peroxidation near their sites of origin if O2 is readily available and antioxidant capacity is overwhelmed. However, recent studies have demonstrated that chain induction is not necessarily limited to a nascent LOOH's immediate surroundings but can extend to other cell membranes or lipoproteins by means of LOOH translocation through the aqueous phase. Mobilization and translocation can also extend the range of LOOHs as redox signaling molecules and in this sense they could act like the small, readily diffusible inorganic analogue H2O2, which has been studied much more extensively in this regard. In this article, basic mechanisms of free-radical- and singlet-oxygen-mediated LOOH formation and one-electron and two-electron LOOH reduction pathways and their biological consequences are reviewed. The first studies to document spontaneous and protein-assisted LOOH transfer in model systems and cells are described. Finally, LOOH translocation is discussed in the context of cytotoxicity vs detoxification and expanded effector action, i.e., redox signaling activity.
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Affiliation(s)
- Albert W Girotti
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI 53226-4801, USA.
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45
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Black SL, Stanley WA, Filipp FV, Bhairo M, Verma A, Wichmann O, Sattler M, Wilmanns M, Schultz C. Probing lipid- and drug-binding domains with fluorescent dyes. Bioorg Med Chem 2007; 16:1162-73. [PMID: 18024138 DOI: 10.1016/j.bmc.2007.10.080] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2007] [Revised: 10/12/2007] [Accepted: 10/23/2007] [Indexed: 11/24/2022]
Abstract
A series of 2- and 3-OH Nile red dyes was prepared in order to generate water-soluble probes that could be used to probe lipid binding to proteins. Various substitutions in positions 2-/3-, 6-, and 7-shifted wavelengths while maintaining the environmental sensitivity of Nile red. In order to increase the solubility of the dyes in aqueous solutions, we attached butyric acid groups to the 2- or 3-OH position. In addition, phenothiazine dyes, which exhibited particularly long excitation properties, were synthesized and tested for the first time. All dyes showed Stoke's shifts of 70-100 nm and changes in excitation and emission of over 100 nm, depending on the hydrophobicity of the environment. Binding studies with bovine serum albumin and the non-specific lipid transfer protein SCP2 revealed emission changes of more than 30 nm upon binding to the protein and a five-fold increase in emission intensity. Titration of the dye-loaded proteins with various lipids or drugs replaced the dye and thereby reversed the shift in wavelength intensity. This allowed us to estimate the lipid binding affinity of the investigated proteins. For SCP2, isothermal calorimetry (ITC) data verified the titration experiments. NMR titration experiments of SCP2 with Nile red 2-O-butyric acid (1a) revealed that the dye is bound within the lipid binding pocket and competes with lipid ligands for this binding site. These results give valuable insight into lipid and drug transport by proteins outside and inside cells.
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Affiliation(s)
- Shannon L Black
- European Molecular Biology Laboratory, Meyerhofstr. 1, 69117 Heidelberg, Germany
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46
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Parr RD, Martin GG, Hostetler HA, Schroeder ME, Mir KD, Kier AB, Ball JM, Schroeder F. A new N-terminal recognition domain in caveolin-1 interacts with sterol carrier protein-2 (SCP-2). Biochemistry 2007; 46:8301-14. [PMID: 17580960 PMCID: PMC3658303 DOI: 10.1021/bi7002636] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Although plasma membrane domains, such as caveolae, provide an organizing principle for signaling pathways and cholesterol homeostasis in the cell, relatively little is known regarding specific mechanisms, whereby intracellular lipid-binding proteins are targeted to caveolae. Therefore, the interaction between caveolin-1 and sterol carrier protein-2 (SCP-2), a protein that binds and transfers both cholesterol and signaling lipids (e.g., phosphatidylinositides and sphingolipids), was examined by yeast two-hybrid, in vitro binding and fluorescence resonance energy transfer (FRET) analyses. Results of the in vivo and in vitro assays identified for the first time the N-terminal amino acids (aa) 1-32 amphipathic alpha helix of SCP-2 functionally interacted with caveolin-1. This interaction was independent of the classic caveolin-1 scaffolding domain, in which many signaling proteins interact. Instead, SCP-2 bound caveolin-1 through a new domain identified in the N-terminal domain of caveolin-1 between aa 34-40. Modeling studies suggested that electrostatic interactions between the SCP-2 N-terminal aa 1-32 amphipathic alpha-helical domain (cationic, positively charged face) and the caveolin-1 N-terminal aa 33-59 alpha helix (anionic, negatively charged face) may significantly contribute to this interaction. These findings provide new insights on how SCP-2 enhances cholesterol retention within the cell as well as regulates the distribution of signaling lipids, such as phosphoinositides and sphingolipids, at plasma membrane caveolae.
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Affiliation(s)
- Rebecca D. Parr
- Department of Pathobiology, Texas A&M University, TVMC, College Station, TX77843-4467
| | - Gregory G. Martin
- Department of Physiology and Pharmacology, Texas A&M University, TVMC, College Station, TX77843-4466
| | - Heather A. Hostetler
- Department of Physiology and Pharmacology, Texas A&M University, TVMC, College Station, TX77843-4466
| | - Megan E. Schroeder
- Department of Pathobiology, Texas A&M University, TVMC, College Station, TX77843-4467
| | - Kiran D. Mir
- Department of Pathobiology, Texas A&M University, TVMC, College Station, TX77843-4467
| | - Ann B. Kier
- Department of Pathobiology, Texas A&M University, TVMC, College Station, TX77843-4467
| | - Judith M. Ball
- Department of Pathobiology, Texas A&M University, TVMC, College Station, TX77843-4467
| | - Friedhelm Schroeder
- Department of Physiology and Pharmacology, Texas A&M University, TVMC, College Station, TX77843-4466
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47
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Abstract
The nonspecific lipid transfer protein sterol carrier protein 2 (SCP2) is involved in organellar fatty acid metabolism. A hydrophobic cavity in the structure of SCP2 accommodates a wide variety of apolar ligands such as cholesterol derivatives or fatty acyl-coenzyme A (CoA) conjugates. The properties of this nonspecific lipid binding pocket are explored using NMR chemical shift perturbations, paramagnetic relaxation enhancement, amide hydrogen exchange, and 15N relaxation measurements. A common binding cavity shared by different physiological ligands is identified. NMR relaxation measurements reveal that residues in the three C-terminal alpha-helices within the lipid binding region exhibit mobility at fast (picosecond to nanosecond) and slow (microsecond to millisecond) time scales. Ligand binding is associated with a considerable loss of peptide backbone mobility. The observed conformational dynamics in SCP2 may play a role for the access of hydrophobic ligands to an occluded binding pocket. The C-terminal peroxisomal targeting signal of SCP2 is specifically recognized by the Pex5p receptor protein, which conducts cargo proteins toward the peroxisomal organelle. Neither the C-terminal targeting signal nor the N-terminal precursor sequence interferes with lipid binding by SCP2. The alpha-helices involved in lipid binding also mediate a secondary interaction interface with the Pex5p receptor. Silencing of conformational dynamics of the peptide backbone in these helices upon either lipid or Pex5p binding might communicate the loading state of the cargo protein to the targeting receptor.
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Affiliation(s)
| | - Michael Sattler
- Corresponding author. Telephone: +49-6221-387-552. Fax: +49-6221-387-98552.
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48
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Schroeder F, Atshaves BP, McIntosh AL, Gallegos AM, Storey SM, Parr RD, Jefferson JR, Ball JM, Kier AB. Sterol carrier protein-2: new roles in regulating lipid rafts and signaling. BIOCHIMICA ET BIOPHYSICA ACTA 2007; 1771:700-18. [PMID: 17543577 PMCID: PMC1989133 DOI: 10.1016/j.bbalip.2007.04.005] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2006] [Revised: 03/28/2007] [Accepted: 04/03/2007] [Indexed: 12/31/2022]
Abstract
Sterol carrier protein-2 (SCP-2) was independently discovered as a soluble protein that binds and transfers cholesterol as well as phospholipids (nonspecific lipid transfer protein, nsLTP) in vitro. Physiological functions of this protein are only now beginning to be resolved. The gene encoding SCP-2 also encodes sterol carrier protein-x (SCP-x) arising from an alternate transcription site. In vitro and in vivo SCP-x serves as a peroxisomal 3-ketoacyl-CoA thiolase in oxidation of branched-chain lipids (cholesterol to form bile acids; branched-chain fatty acid for detoxification). While peroxisomal SCP-2 facilitates branched-chain lipid oxidation, the role(s) of extraperoxisomal (up to 50% of total) are less clear. Studies using transfected fibroblasts overexpressing SCP-2 and hepatocytes from SCP-2/SCP-x gene-ablated mice reveal that SCP-2 selectively remodels the lipid composition, structure, and function of lipid rafts/caveolae. Studies of purified SCP-2 and in cells show that SCP-2 has high affinity for and selectively transfers many lipid species involved in intracellular signaling: fatty acids, fatty acyl CoAs, lysophosphatidic acid, phosphatidylinositols, and sphingolipids (sphingomyelin, ceramide, mono-di-and multi-hexosylceramides, gangliosides). SCP-2 selectively redistributes these signaling lipids between lipid rafts/caveolae and intracellular sites. These findings suggest SCP-2 serves not only in cholesterol and phospholipid transfer, but also in regulating multiple lipid signaling pathways in lipid raft/caveolae microdomains of the plasma membrane.
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Affiliation(s)
- Friedhelm Schroeder
- Department of Physiology and Pharmacology, Texas A&M University, TVMC, College Station, TX 77843-4466, USA.
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49
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Stanley WA, Versluis K, Schultz C, Heck AJR, Wilmanns M. Investigation of the ligand spectrum of human sterol carrier protein 2 using a direct mass spectrometry assay. Arch Biochem Biophys 2007; 461:50-8. [PMID: 17418802 DOI: 10.1016/j.abb.2007.02.026] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2006] [Revised: 02/11/2007] [Accepted: 02/12/2007] [Indexed: 11/17/2022]
Abstract
Sterol carrier protein 2 (SCP2) has been investigated by nearly native electrospray ionisation mass spectrometry in the presence of long chain fatty acyl CoAs (LCFA-CoAs) and carnitine derivatives of equivalent fatty acid chain length (LCFA-carnitines). Four SCP2 constructs were compared to examine the influence of the N-terminal presequence and the C-terminal peroxisomal targeting signal on ligand binding. Removal of N- or C-terminal residues did not influence ligand binding. The observation that LCFA-CoAs are high affinity ligands for SCP2 was confirmed, while LCFA-carnitines were demonstrated for the first time not to interact with SCP2. LCFA-CoAs formed non-covalent complexes with SCP2 of 2:1 and 1:1 stoichiometry, which could be dissociated by elevating the energy of the ions upon entrance to the mass spectrometer. A fluorescence-competition assay using Nile Red butyric acid confirmed the mass spectrometric observations in solution. The physiological significance of the lack of LCFA-carnitine binding by SCP2 is discussed.
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Affiliation(s)
- Will A Stanley
- EMBL-Hamburg, c/o DESY, Notkestrasse 85, 22603 Hamburg, Germany.
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50
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Kernstock RM, Girotti AW. Lipid transfer protein binding of unmodified natural lipids as assessed by surface plasmon resonance methodology. Anal Biochem 2007; 365:111-21. [PMID: 17376396 PMCID: PMC1975857 DOI: 10.1016/j.ab.2007.02.018] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2007] [Accepted: 02/16/2007] [Indexed: 12/12/2022]
Abstract
A new approach for analyzing lipid-lipid transfer protein interactions is described. The transfer protein is genetically engineered for expression with a C-terminal biotinylated peptide extension (AviTag). This allows protein anchoring to a streptavidin-coated chip for surface plasmon resonance (SPR)-based assessment of lipid binding. Sterol carrier protein-2 (SCP-2), involved in the intracellular trafficking of cholesterol, fatty acids, and other lipids, was selected as the prototype. Biotinylated SCP-2 (bSCP-2) was expressed in Escherichia coli, purified to homogeneity by mutated streptavidin (SoftLink) affinity chromatography, and confirmed by mass spectrometry to contain one biotin group at the expected position. Intermembrane [(14)C]cholesterol transfer was strongly enhanced by bSCP-2, demonstrating that it was functional. Using bSCP-2 immobilized on a Biacore streptavidin chip, we determined on- and off-rate constants along with equilibrium dissociation constants for the following analytes: oleic acid, linoleic acid, cholesterol, and fluorophore (NBD)-derivatized cholesterol. The dissociation constant for NBD-cholesterol was similar to that determined by fluorescence titration for SCP-2 in solution, thereby validating the SPR approach. This method can be readily adapted to other transfer proteins and has several advantages over existing techniques for measuring lipid binding, including (i) the ability to study lipids in their natural states (i.e., without relatively large reporter groups) and (ii) the ability to measure on- and off- rate constants as well as equilibrium constants.
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Affiliation(s)
| | - Albert W. Girotti
- *To whom correspondence should be addressed: Dr. Albert W. Girotti, Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI, 53226, Tel: 414-456-8432, Fax: 414-456-6510, E-mail:
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