251
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Lange Y, Steck TL. Active membrane cholesterol as a physiological effector. Chem Phys Lipids 2016; 199:74-93. [PMID: 26874289 DOI: 10.1016/j.chemphyslip.2016.02.003] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Revised: 02/04/2016] [Accepted: 02/08/2016] [Indexed: 02/05/2023]
Abstract
Sterols associate preferentially with plasma membrane sphingolipids and saturated phospholipids to form stoichiometric complexes. Cholesterol in molar excess of the capacity of these polar bilayer lipids has a high accessibility and fugacity; we call this fraction active cholesterol. This review first considers how active cholesterol serves as an upstream regulator of cellular sterol homeostasis. The mechanism appears to utilize the redistribution of active cholesterol down its diffusional gradient to the endoplasmic reticulum and mitochondria, where it binds multiple effectors and directs their feedback activity. We have also reviewed a broad literature in search of a role for active cholesterol (as opposed to bulk cholesterol or lipid domains such as rafts) in the activity of diverse membrane proteins. Several systems provide such evidence, implicating, in particular, caveolin-1, various kinds of ABC-type cholesterol transporters, solute transporters, receptors and ion channels. We suggest that this larger role for active cholesterol warrants close attention and can be tested easily.
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Affiliation(s)
- Yvonne Lange
- Department of Pathology, Rush University Medical Center, 1653 W. Congress Parkway, Chicago, IL 60612, USA.
| | - Theodore L Steck
- Department of Biochemistry and Molecular Biology, University of Chicago, 929 East 57th Street, Chicago, IL 60637, USA.
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252
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Cytochrome P450 20A1 in zebrafish: Cloning, regulation and potential involvement in hyperactivity disorders. Toxicol Appl Pharmacol 2016; 296:73-84. [PMID: 26853319 DOI: 10.1016/j.taap.2016.02.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Revised: 01/29/2016] [Accepted: 02/01/2016] [Indexed: 12/17/2022]
Abstract
Cytochrome P450 (CYP) enzymes for which there is no functional information are considered "orphan" CYPs. Previous studies showed that CYP20A1, an orphan, is expressed in human hippocampus and substantia nigra, and in zebrafish (Danio rerio) CYP20A1 maternal transcript occurs in eggs, suggesting involvement in brain and in early development. Moreover, hyperactivity is reported in humans with chromosome 2 microdeletions including CYP20A1. We examined CYP20A1 in zebrafish, including impacts of chemical exposure on expression. Zebrafish CYP20A1 cDNA was cloned, sequenced, and aligned with cloned human CYP20A1 and predicted vertebrate orthologs. CYP20A1s share a highly conserved N-terminal region and unusual sequences in the I-helix and the heme-binding CYP signature motifs. CYP20A1 mRNA expression was observed in adult zebrafish organs including the liver, heart, gonads, spleen and brain, as well as the eye and optic nerve. Putative binding sites in proximal promoter regions of CYP20A1s, and response of zebrafish CYP20A1 to selected nuclear and xenobiotic receptor agonists, point to up-regulation by agents involved in steroid hormone response, cholesterol and lipid metabolism. There also was a dose-dependent reduction of CYP20A1 expression in embryos exposed to environmentally relevant levels of methylmercury. Morpholino knockdown of CYP20A1 in developing zebrafish resulted in behavioral effects, including hyperactivity and a slowing of the optomotor response in larvae. The results suggest that altered expression of CYP20A1 might be part of a mechanism linking methylmercury exposure to neurobehavioral deficits. The expanded information on CYP20A1 brings us closer to "deorphanization", that is, identifying CYP20A1 functions and its roles in health and disease.
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253
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Haberkant P, Stein F, Höglinger D, Gerl MJ, Brügger B, Van Veldhoven PP, Krijgsveld J, Gavin AC, Schultz C. Bifunctional Sphingosine for Cell-Based Analysis of Protein-Sphingolipid Interactions. ACS Chem Biol 2016; 11:222-30. [PMID: 26555438 DOI: 10.1021/acschembio.5b00810] [Citation(s) in RCA: 88] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Sphingolipids are essential structural components of cellular membranes and are crucial regulators of cellular processes. While current high-throughput approaches allow for the systematic mapping of interactions of soluble proteins with their lipid-binding partners, photo-cross-linking is the only technique that enables for the proteome-wide mapping of integral membrane proteins with their direct lipid environment. Here, we report the synthesis of a photoactivatable and clickable analog of sphingosine (pacSph). When administered to sphingosine-1-phosphate lyase deficient cells, pacSph allows its metabolic fate and the subcellular flux of de novo synthesized sphingolipids to be followed in a time-resolved manner. The chemoproteomic profiling yielded over 180 novel sphingolipid-binding proteins, of which we validated a number, demonstrating the unique value of this technique as a discovery tool. This work provides an important resource for the understanding of the global cellular interplay between sphingolipids and their interacting proteins.
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Affiliation(s)
- Per Haberkant
- European Molecular Biology Laboratory, Cell Biology
and Biophysics Unit, Meyerhofstr.
1, 69117 Heidelberg, Germany
| | - Frank Stein
- European Molecular Biology Laboratory, Cell Biology
and Biophysics Unit, Meyerhofstr.
1, 69117 Heidelberg, Germany
| | - Doris Höglinger
- European Molecular Biology Laboratory, Cell Biology
and Biophysics Unit, Meyerhofstr.
1, 69117 Heidelberg, Germany
| | - Mathias J. Gerl
- Heidelberg University Biochemistry Center, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany
| | - Britta Brügger
- Heidelberg University Biochemistry Center, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany
| | - Paul P. Van Veldhoven
- Laboratory
for Lipid Biochemistry and Protein Interactions, Department of Cellular
and Molecular Medicine, KU Leuven, B-3000 Leuven, Belgium
| | - Jeroen Krijgsveld
- European Molecular Biology Laboratory, Genome Biology
Unit, Meyerhofstr. 1, 69117 Heidelberg, Germany
| | - Anne-Claude Gavin
- European Molecular Biology Laboratory, Structural
and Computational Biology Unit, Meyerhofstr. 1, 69117 Heidelberg, Germany
| | - Carsten Schultz
- European Molecular Biology Laboratory, Cell Biology
and Biophysics Unit, Meyerhofstr.
1, 69117 Heidelberg, Germany
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254
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Transition-Metal-Catalyzed Bioorthogonal Cycloaddition Reactions. Top Curr Chem (Cham) 2015; 374:2. [DOI: 10.1007/s41061-015-0001-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Accepted: 11/11/2015] [Indexed: 01/20/2023]
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255
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Martins IJ. Overnutrition Determines LPS Regulation of Mycotoxin Induced Neurotoxicity in Neurodegenerative Diseases. Int J Mol Sci 2015; 16:29554-73. [PMID: 26690419 PMCID: PMC4691133 DOI: 10.3390/ijms161226190] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Revised: 11/19/2015] [Accepted: 12/01/2015] [Indexed: 12/11/2022] Open
Abstract
Chronic neurodegenerative diseases are now associated with obesity and diabetes and linked to the developing and developed world. Interests in healthy diets have escalated that may prevent neurodegenerative diseases such as Parkinson's and Alzheimer's disease. The global metabolic syndrome involves lipoprotein abnormalities and insulin resistance and is the major disorder for induction of neurological disease. The effects of bacterial lipopolysaccharides (LPS) on dyslipidemia and NAFLD indicate that the clearance and metabolism of fungal mycotoxins are linked to hypercholesterolemia and amyloid beta oligomers. LPS and mycotoxins are associated with membrane lipid disturbances with effects on cholesterol interacting proteins, lipoprotein metabolism, and membrane apo E/amyloid beta interactions relevant to hypercholesterolemia with close connections to neurological diseases. The influence of diet on mycotoxin metabolism has accelerated with the close association between mycotoxin contamination from agricultural products such as apple juice, grains, alcohol, and coffee. Cholesterol efflux in lipoproteins and membrane cholesterol are determined by LPS with involvement of mycotoxin on amyloid beta metabolism. Nutritional interventions such as diets low in fat/carbohydrate/cholesterol have become of interest with relevance to low absorption of lipophilic LPS and mycotoxin into lipoproteins with rapid metabolism of mycotoxin to the liver with the prevention of neurodegeneration.
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Affiliation(s)
- Ian James Martins
- Centre of Excellence in Alzheimer's Disease Research and Care, School of Medical Sciences, Edith Cowan University, 270 Joondalup Drive, Joondalup 6027, Australia.
- School of Psychiatry and Clinical Neurosciences, The University of Western Australia, Nedlands 6009, Australia.
- McCusker Alzheimer's Research Foundation, Hollywood Medical Centre, 85 Monash Avenue, Suite 22, Nedlands 6009, Australia.
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256
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Moriyama A, Katagiri N, Nishimura S, Takahashi N, Kakeya H. In Vivo Linking of Membrane Lipids and the Anion Transporter Band 3 with Thiourea-modified Amphiphilic Lipid Probes. Sci Rep 2015; 5:17427. [PMID: 26616474 PMCID: PMC4663539 DOI: 10.1038/srep17427] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Accepted: 10/29/2015] [Indexed: 12/23/2022] Open
Abstract
Membrane proteins interact with membrane lipids for their structural stability and proper function. However, lipid–protein interactions are poorly understood at a molecular level especially in the live cell membrane, due to current limitations in methodology. Here, we report that amphiphilic lipid probes can be used to link membrane lipids and membrane proteins in vivo. Cholesterol and a phospholipid were both conjugated to a fluorescent tag through a linker containing thiourea. In the erythrocyte, the cholesterol probe fluorescently tagged the anion transporter band 3 via thiourea. Tagging by the cholesterol probe, but not by the phospholipid probe, was competitive with an anion transporter inhibitor, implying the presence of a specific binding pocket for cholesterol in this ~100 kDa protein. This method could prove an effective strategy for analyzing lipid–protein interactions in vivo in the live cell membrane.
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Affiliation(s)
- Akihiro Moriyama
- Department of System Chemotherapy and Molecular Sciences, Division of Bioinformatics and Chemical Genomics, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Naohiro Katagiri
- Department of System Chemotherapy and Molecular Sciences, Division of Bioinformatics and Chemical Genomics, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Shinichi Nishimura
- Department of System Chemotherapy and Molecular Sciences, Division of Bioinformatics and Chemical Genomics, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Nobuaki Takahashi
- Department of System Chemotherapy and Molecular Sciences, Division of Bioinformatics and Chemical Genomics, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Hideaki Kakeya
- Department of System Chemotherapy and Molecular Sciences, Division of Bioinformatics and Chemical Genomics, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
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257
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Shen WJ, Azhar S, Kraemer FB. Lipid droplets and steroidogenic cells. Exp Cell Res 2015; 340:209-14. [PMID: 26639173 DOI: 10.1016/j.yexcr.2015.11.024] [Citation(s) in RCA: 111] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Revised: 11/23/2015] [Accepted: 11/25/2015] [Indexed: 02/05/2023]
Abstract
Lipid droplets (LDs) in steroidogenic tissues have a cholesteryl ester (CE) core surrounded by a phospholipid monolayer that is coated with associated proteins. Compared with other tissues, they tend to be smaller in size and more numerous in numbers. These LDs are enriched with PLIN1c, PLIN2 and PLIN3. Both CIDE A and B are found in mouse ovary. Free cholesterol (FC) released upon hormone stimulation from LDs is the preferred source of cholesterol substrate for steroidogenesis, and HSL is the major neutral cholesterol esterase mediating the conversion of CEs to FC. Through the interaction of HSL with vimentin and StAR, FC is translocated to mitochondria for steroid hormone production. Proteomic analyses of LDs isolated from loaded primary ovarian granulosa cells, mouse MLTC-1 Leydig tumor cells and mouse testes revealed LD associated proteins that are actively involved in modulating lipid homeostasis along with a number of steroidogenic enzymes. Microscopy analysis confirmed the localization of many of these proteins to LDs. These studies broaden the role of LDs to include being a platform for functional steroidogenic enzyme activity or as a port for transferring steroidogenic enzymes and/or steroid intermediates, in addition to being a storage depot for CEs.
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Affiliation(s)
- Wen-Jun Shen
- Division of Endocrinology, Gerontology and Metabolism, Stanford University, Stanford, CA 94305, United States; Veterans Affairs Palo Alto Health Care System, Palo Alto, CA 94304, United States
| | - Salman Azhar
- Division of Endocrinology, Gerontology and Metabolism, Stanford University, Stanford, CA 94305, United States; Veterans Affairs Palo Alto Health Care System, Palo Alto, CA 94304, United States
| | - Fredric B Kraemer
- Division of Endocrinology, Gerontology and Metabolism, Stanford University, Stanford, CA 94305, United States; Veterans Affairs Palo Alto Health Care System, Palo Alto, CA 94304, United States.
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258
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Gu X, Huang Y, Levison BS, Gerstenecker G, DiDonato AJ, Hazen LB, Lee J, Gogonea V, DiDonato JA, Hazen SL. Identification of Critical Paraoxonase 1 Residues Involved in High Density Lipoprotein Interaction. J Biol Chem 2015; 291:1890-1904. [PMID: 26567339 DOI: 10.1074/jbc.m115.678334] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2015] [Indexed: 11/06/2022] Open
Abstract
Paraoxonase 1 (PON1) is a high density lipoprotein (HDL)-associated protein with atherosclerosis-protective and systemic anti-oxidant functions. We recently showed that PON1, myeloperoxidase, and HDL bind to one another in vivo forming a functional ternary complex (Huang, Y., Wu, Z., Riwanto, M., Gao, S., Levison, B. S., Gu, X., Fu, X., Wagner, M. A., Besler, C., Gerstenecker, G., Zhang, R., Li, X. M., Didonato, A. J., Gogonea, V., Tang, W. H., et al. (2013) J. Clin. Invest. 123, 3815-3828). However, specific residues on PON1 involved in the HDL-PON1 interaction remain unclear. Unambiguous identification of protein residues involved in docking interactions to lipid surfaces poses considerable methodological challenges. Here we describe a new strategy that uses a novel synthetic photoactivatable and click chemistry-taggable phospholipid probe, which, when incorporated into HDL, was used to identify amino acid residues on PON1 that directly interact with the lipoprotein phospholipid surface. Several specific PON1 residues (Leu-9, Tyr-185, and Tyr-293) were identified through covalent cross-links with the lipid probes using affinity isolation coupled to liquid chromatography with on-line tandem mass spectrometry. Based upon the crystal structure for PON1, the identified residues are all localized in relatively close proximity on the surface of PON1, defining a domain that binds to the HDL lipid surface. Site-specific mutagenesis of the identified PON1 residues (Leu-9, Tyr-185, and Tyr-293), coupled with functional studies, reveals their importance in PON1 binding to HDL and both PON1 catalytic activity and stability. Specifically, the residues identified on PON1 provide important structural insights into the PON1-HDL interaction. More generally, the new photoactivatable and affinity-tagged lipid probe developed herein should prove to be a valuable tool for identifying contact sites supporting protein interactions with lipid interfaces such as found on cell membranes or lipoproteins.
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Affiliation(s)
- Xiaodong Gu
- From the Department of Cellular and Molecular Medicine, Center for Cardiovascular Diagnostics and Prevention, and
| | - Ying Huang
- From the Department of Cellular and Molecular Medicine, Center for Cardiovascular Diagnostics and Prevention, and
| | - Bruce S Levison
- From the Department of Cellular and Molecular Medicine, Center for Cardiovascular Diagnostics and Prevention, and
| | - Gary Gerstenecker
- the Department of Chemistry, Cleveland State University, Cleveland, Ohio 44115
| | - Anthony J DiDonato
- From the Department of Cellular and Molecular Medicine, Center for Cardiovascular Diagnostics and Prevention, and
| | - Leah B Hazen
- From the Department of Cellular and Molecular Medicine, Center for Cardiovascular Diagnostics and Prevention, and.
| | - Joonsue Lee
- From the Department of Cellular and Molecular Medicine, Center for Cardiovascular Diagnostics and Prevention, and
| | - Valentin Gogonea
- From the Department of Cellular and Molecular Medicine, Center for Cardiovascular Diagnostics and Prevention, and; the Department of Chemistry, Cleveland State University, Cleveland, Ohio 44115
| | - Joseph A DiDonato
- From the Department of Cellular and Molecular Medicine, Center for Cardiovascular Diagnostics and Prevention, and
| | - Stanley L Hazen
- From the Department of Cellular and Molecular Medicine, Center for Cardiovascular Diagnostics and Prevention, and; Department of Cardiovascular Medicine, Cleveland Clinic, Cleveland, Ohio 44195 and
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259
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Gamo AM, González-Vera JA, Rueda-Zubiaurre A, Alonso D, Vázquez-Villa H, Martín-Couce L, Palomares Ó, López JA, Martín-Fontecha M, Benhamú B, López-Rodríguez ML, Ortega-Gutiérrez S. Chemoproteomic Approach to Explore the Target Profile of GPCR ligands: Application to 5-HT1A
and 5-HT6
Receptors. Chemistry 2015; 22:1313-21. [DOI: 10.1002/chem.201503101] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Indexed: 12/20/2022]
Affiliation(s)
- Ana M. Gamo
- Departamento de Química Orgánica I; Facultad de Ciencias Químicas; Universidad Complutense de Madrid; 28040 Madrid Spain
| | - Juan A. González-Vera
- Departamento de Química Orgánica I; Facultad de Ciencias Químicas; Universidad Complutense de Madrid; 28040 Madrid Spain
| | - Ainoa Rueda-Zubiaurre
- Departamento de Química Orgánica I; Facultad de Ciencias Químicas; Universidad Complutense de Madrid; 28040 Madrid Spain
| | - Dulce Alonso
- Departamento de Química Orgánica I; Facultad de Ciencias Químicas; Universidad Complutense de Madrid; 28040 Madrid Spain
| | - Henar Vázquez-Villa
- Departamento de Química Orgánica I; Facultad de Ciencias Químicas; Universidad Complutense de Madrid; 28040 Madrid Spain
| | - Lidia Martín-Couce
- Departamento de Química Orgánica I; Facultad de Ciencias Químicas; Universidad Complutense de Madrid; 28040 Madrid Spain
| | - Óscar Palomares
- Departamento de Bioquímica y Biología Molecular I; Facultad de Ciencias Químicas; Universidad Complutense de Madrid; 28040 Madrid Spain
| | - Juan A. López
- Proteomics Unit; Centro Nacional de Investigaciones Cardiovasculares, CNIC; 28029 Madrid Spain
| | - Mar Martín-Fontecha
- Departamento de Química Orgánica I; Facultad de Ciencias Químicas; Universidad Complutense de Madrid; 28040 Madrid Spain
| | - Bellinda Benhamú
- Departamento de Química Orgánica I; Facultad de Ciencias Químicas; Universidad Complutense de Madrid; 28040 Madrid Spain
| | - María L. López-Rodríguez
- Departamento de Química Orgánica I; Facultad de Ciencias Químicas; Universidad Complutense de Madrid; 28040 Madrid Spain
| | - Silvia Ortega-Gutiérrez
- Departamento de Química Orgánica I; Facultad de Ciencias Químicas; Universidad Complutense de Madrid; 28040 Madrid Spain
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260
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Richter JP, Goroncy AK, Ronimus RS, Sutherland-Smith AJ. The Structural and Functional Characterization of Mammalian ADP-dependent Glucokinase. J Biol Chem 2015; 291:3694-704. [PMID: 26555263 DOI: 10.1074/jbc.m115.679902] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Indexed: 12/24/2022] Open
Abstract
The enzyme-catalyzed phosphorylation of glucose to glucose-6-phosphate is a reaction central to the metabolism of all life. ADP-dependent glucokinase (ADPGK) catalyzes glucose-6-phosphate production, utilizing ADP as a phosphoryl donor in contrast to the more well characterized ATP-requiring hexokinases. ADPGK is found in Archaea and metazoa; in Archaea, ADPGK participates in a glycolytic role, but a function in most eukaryotic cell types remains unknown. We have determined structures of the eukaryotic ADPGK revealing a ribokinase-like tertiary fold similar to archaeal orthologues but with significant differences in some secondary structural elements. Both the unliganded and the AMP-bound ADPGK structures are in the "open" conformation. The structures reveal the presence of a disulfide bond between conserved cysteines that is positioned at the nucleotide-binding loop of eukaryotic ADPGK. The AMP-bound ADPGK structure defines the nucleotide-binding site with one of the disulfide bond cysteines coordinating the AMP with its main chain atoms, a nucleotide-binding motif that appears unique to eukaryotic ADPGKs. Key amino acids at the active site are structurally conserved between mammalian and archaeal ADPGK, and site-directed mutagenesis has confirmed residues essential for enzymatic activity. ADPGK is substrate inhibited by high glucose concentration and shows high specificity for glucose, with no activity for other sugars, as determined by NMR spectroscopy, including 2-deoxyglucose, the glucose analogue used for tumor detection by positron emission tomography.
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Affiliation(s)
- Jan P Richter
- From the Institute of Fundamental Sciences, Massey University, Palmerston North 4410, New Zealand and
| | - Alexander K Goroncy
- From the Institute of Fundamental Sciences, Massey University, Palmerston North 4410, New Zealand and
| | - Ron S Ronimus
- AgResearch Limited, Palmerston North 4442, New Zealand
| | - Andrew J Sutherland-Smith
- From the Institute of Fundamental Sciences, Massey University, Palmerston North 4410, New Zealand and
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261
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Abstract
Chemical biology has a significant role to play in the discovery and validation of new therapeutic targets. Activity- and affinity-based probes have demonstrated considerable promise in the drug discovery setting as they provide a chemoproteomic means to confirm and quantify target engagement and selectivity of small molecule drug candidates. Many of these technologies have been developed using cell lysate (through the use of resin-immobilized enzyme inhibitors for example), but this does not represent the biology of an intact cell. This review highlights recent advances made in the design and application of cell-permeable probes that report on target activity and drug-target occupancy in living cells, thus providing a means to decipher molecular pharmacology and pathology in a more physiologically relevant manner.
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262
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Saliba AE, Vonkova I, Gavin AC. The systematic analysis of protein-lipid interactions comes of age. Nat Rev Mol Cell Biol 2015; 16:753-61. [PMID: 26507169 DOI: 10.1038/nrm4080] [Citation(s) in RCA: 134] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Lipids tailor membrane identities and function as molecular hubs in all cellular processes. However, the ways in which lipids modulate protein function and structure are poorly understood and still require systematic investigation. In this Innovation article, we summarize pioneering technologies, including lipid-overlay assays, lipid pull-down assays, affinity-purification lipidomics and the liposome microarray-based assay (LiMA), that will enable protein-lipid interactions to be deciphered on a systems level. We discuss how these technologies can be applied to the charting of system-wide networks and to the development of new pharmaceutical strategies.
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Affiliation(s)
- Antoine-Emmanuel Saliba
- Institute for Molecular Infection Biology and Core Unit Systems Medicine, University of Würzburg, Josef-Schneider-Strasse 2, D-97080 Würzburg, Germany
| | - Ivana Vonkova
- European Molecular Biology Laboratory (EMBL), Structural and Computational Biology Unit, Meyerhofstrasse 1, D-69117 Heidelberg, Germany
| | - Anne-Claude Gavin
- European Molecular Biology Laboratory (EMBL), Structural and Computational Biology Unit and Molecular Medicine Partnership Unit, Meyerhofstrasse 1, D-69117 Heidelberg, Germany
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263
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Callahan BP, Wang C. Hedgehog Cholesterolysis: Specialized Gatekeeper to Oncogenic Signaling. Cancers (Basel) 2015; 7:2037-53. [PMID: 26473928 PMCID: PMC4695875 DOI: 10.3390/cancers7040875] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Revised: 09/22/2015] [Accepted: 09/28/2015] [Indexed: 12/16/2022] Open
Abstract
Discussions of therapeutic suppression of hedgehog (Hh) signaling almost exclusively focus on receptor antagonism; however, hedgehog's biosynthesis represents a unique and potentially targetable aspect of this oncogenic signaling pathway. Here, we review a key biosynthetic step called cholesterolysis from the perspectives of structure/function and small molecule inhibition. Cholesterolysis, also called cholesteroylation, generates cholesterol-modified Hh ligand via autoprocessing of a hedgehog precursor protein. Post-translational modification by cholesterol appears to be restricted to proteins in the hedgehog family. The transformation is essential for Hh biological activity and upstream of signaling events. Despite its decisive role in generating ligand, cholesterolysis remains conspicuously unexplored as a therapeutic target.
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Affiliation(s)
- Brian P Callahan
- Chemistry Department, Binghamton University 4400 Vestal Parkway East, Binghamton, NY 13902, USA.
| | - Chunyu Wang
- Biology Department, Rensselaer Polytechnic Institute, 110 8th Street, Troy, NY 12180, USA.
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264
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Hymel D, Cai S, Sun Q, Henkhaus RS, Perera C, Peterson BR. Fluorescent mimics of cholesterol that rapidly bind surfaces of living mammalian cells. Chem Commun (Camb) 2015; 51:14624-7. [PMID: 26287483 DOI: 10.1039/c5cc06325f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Mammalian cells acquire cholesterol, a critical membrane constituent, through multiple mechanisms. We synthesized mimics of cholesterol, fluorescent N-alkyl-3β-cholesterylamine-glutamic acids, that are rapidly incorporated into cellular plasma membranes compared with analogous cholesteryl amides, ethers, esters, carbamates, and a sitosterol analogue. This process was inhibited by ezetimibe, indicating a receptor-mediated uptake pathway.
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Affiliation(s)
- David Hymel
- The University of Kansas, Department of Medicinal Chemistry, Lawrence, KS 66045, USA.
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265
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Howe V, Chua NK, Stevenson J, Brown AJ. The Regulatory Domain of Squalene Monooxygenase Contains a Re-entrant Loop and Senses Cholesterol via a Conformational Change. J Biol Chem 2015; 290:27533-44. [PMID: 26434806 DOI: 10.1074/jbc.m115.675181] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Indexed: 11/06/2022] Open
Abstract
Squalene monooxygenase (SM) is an important control point in cholesterol synthesis beyond 3-hydroxy-3-methylglutaryl-CoA reductase. Although it is known to associate with the endoplasmic reticulum, its topology has not been determined. We have elucidated the membrane topology of the sterol-responsive domain of SM comprising the first 100 amino acids fused to GFP (SM N100-GFP) by determining the accessibility of 16 introduced cysteines to the cysteine-reactive, membrane-impermeable reagent PEG-maleimide. We have identified a region integrally associated with the endoplasmic reticulum membrane that is likely to interact with cholesterol or respond to cholesterol-induced membrane effects. By comparing cysteine accessibility with and without cholesterol treatment, we further present evidence to suggest that cholesterol induces a conformational change in SM N100-GFP. This change is likely to lead to its targeted degradation by the ubiquitin-proteasome system because degradation is blunted by treatment with the chemical chaperone glycerol, which retains SM N100-GFP in its native conformation. Furthermore, degradation can be disrupted by insertion of two N-terminal myc tags, implicating the N terminus in this process. Together, this information provides new molecular insights into the regulation of this critical control point in cholesterol synthesis.
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Affiliation(s)
- Vicky Howe
- From the School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney 2052, Australia and
| | - Ngee Kiat Chua
- From the School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney 2052, Australia and
| | - Julian Stevenson
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, California 94720
| | - Andrew J Brown
- From the School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney 2052, Australia and
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266
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Recent developments and applications of clickable photoprobes in medicinal chemistry and chemical biology. Future Med Chem 2015; 7:2143-71. [DOI: 10.4155/fmc.15.136] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Photoaffinity labeling is a well-known biochemical technique that has grown significantly since the turn of the century, principally due to its combination with bioorthogonal/click chemistry reactions. This review highlights new developments and applications of clickable photoprobes in medicinal chemistry and chemical biology. In particular, recent examples of clickable photoprobes for target identification, activity- or affinity-based protein profiling (ABPP or AfBPP), characterization of sterol– or lipid–protein interactions and characterization of ligand-binding sites are presented.
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267
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Hoque M, Rentero C, Conway JR, Murray RZ, Timpson P, Enrich C, Grewal T. The cross-talk of LDL-cholesterol with cell motility: insights from the Niemann Pick Type C1 mutation and altered integrin trafficking. Cell Adh Migr 2015; 9:384-91. [PMID: 26366834 DOI: 10.1080/19336918.2015.1019996] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Cholesterol is considered indispensible for the recruitment and functioning of integrins in focal adhesions for cell migration. However, the physiological cholesterol pools that control integrin trafficking and focal adhesion assembly remain unclear. Using Niemann Pick Type C1 (NPC) mutant cells, which accumulate Low Density lipoprotein (LDL)-derived cholesterol in late endosomes (LE), several recent studies indicate that LDL-cholesterol has multiple roles in regulating focal adhesion dynamics. Firstly, targeting of endocytosed LDL-cholesterol from LE to focal adhesions controls their formation at the leading edge of migrating cells. Other newly emerging literature suggests that this may be coupled to vesicular transport of integrins, Src kinase and metalloproteases from the LE compartment to focal adhesions. Secondly, our recent work identified LDL-cholesterol as a key factor that determines the distribution and ability of several Soluble NSF Attachment Protein (SNAP) Receptor (SNARE) proteins, key players in vesicle transport, to control integrin trafficking to the cell surface and extracellular matrix (ECM) secretion. Collectively, dietary, genetic and pathological changes in cholesterol metabolism may link with efficiency and speed of integrin and ECM cell surface delivery in metastatic cancer cells. This commentary will summarize how direct and indirect pathways enable LDL-cholesterol to modulate cell motility.
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Affiliation(s)
- Monira Hoque
- a Faculty of Pharmacy; University of Sydney ; Sydney , Australia
| | - Carles Rentero
- b Departament de Biologia Cellular ; Immunologia i Neurociències; Centre de Recerca Biomèdica CELLEX; Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS); Facultat de Medicina; Universitat de Barcelona ; Barcelona , Spain
| | - James R Conway
- c Cancer Research Program; The Kinghorn Cancer Center; Garvan Institute of Medical Research ; Darlinghurst , Australia
| | - Rachael Z Murray
- d Tissue Repair and Regeneration Program; Institute of Health and Biomedical Innovation; Queensland University of Technology ; Brisbane , Australia
| | - Paul Timpson
- c Cancer Research Program; The Kinghorn Cancer Center; Garvan Institute of Medical Research ; Darlinghurst , Australia
| | - Carlos Enrich
- b Departament de Biologia Cellular ; Immunologia i Neurociències; Centre de Recerca Biomèdica CELLEX; Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS); Facultat de Medicina; Universitat de Barcelona ; Barcelona , Spain
| | - Thomas Grewal
- a Faculty of Pharmacy; University of Sydney ; Sydney , Australia
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268
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Wüstner D, Solanko K. How cholesterol interacts with proteins and lipids during its intracellular transport. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2015; 1848:1908-26. [DOI: 10.1016/j.bbamem.2015.05.010] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2015] [Revised: 04/14/2015] [Accepted: 05/13/2015] [Indexed: 12/13/2022]
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269
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A Global Map of Lipid-Binding Proteins and Their Ligandability in Cells. Cell 2015; 161:1668-80. [PMID: 26091042 DOI: 10.1016/j.cell.2015.05.045] [Citation(s) in RCA: 170] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Revised: 02/24/2015] [Accepted: 05/04/2015] [Indexed: 01/17/2023]
Abstract
Lipids play central roles in physiology and disease, where their structural, metabolic, and signaling functions often arise from interactions with proteins. Here, we describe a set of lipid-based chemical proteomic probes and their global interaction map in mammalian cells. These interactions involve hundreds of proteins from diverse functional classes and frequently occur at sites of drug action. We determine the target profiles for several drugs across the lipid-interaction proteome, revealing that its ligandable content extends far beyond traditionally defined categories of druggable proteins. In further support of this finding, we describe a selective ligand for the lipid-binding protein nucleobindin-1 (NUCB1) and show that this compound perturbs the hydrolytic and oxidative metabolism of endocannabinoids in cells. The described chemical proteomic platform thus provides an integrated path to both discover and pharmacologically characterize a wide range of proteins that participate in lipid pathways in cells.
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270
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Ganesan L, Levental I. Pharmacological Inhibition of Protein Lipidation. J Membr Biol 2015; 248:929-41. [PMID: 26280397 DOI: 10.1007/s00232-015-9835-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Accepted: 08/07/2015] [Indexed: 01/02/2023]
Abstract
Lipid modifications of mammalian proteins are widespread, modifying thousands of targets involved in all aspects of cellular physiology cellular physiology. Broadly, lipidations serve to increase protein hydrophobicity and association with cellular membranes. Often, these modifications are absolutely essential for protein stability and localization, and serve critical roles in dynamic regulation of protein function. A number of lipidated proteins are associated with diseases, including parasite infections, neurological diseases, diabetes, and cancer, suggesting that lipid modifications represent potentially attractive targets for pharmacological intervention. This review briefly describes the various types of posttranslational protein lipid modifications, proteins modified by them, and the enzymatic machinery associated with these. We then discuss several case studies demonstrating successful development of lipidation inhibitors of potential (and more rarely, realized) clinical value. Although this field remains in its infancy, we believe these examples demonstrate the potential utility of targeting protein lipidation as a viable strategy for inhibiting the function of pathogenic proteins.
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Affiliation(s)
| | - Ilya Levental
- University of Texas Medical School, Houston, TX, USA.
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271
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Terai T, Kohno M, Boncompain G, Sugiyama S, Saito N, Fujikake R, Ueno T, Komatsu T, Hanaoka K, Okabe T, Urano Y, Perez F, Nagano T. Artificial Ligands of Streptavidin (ALiS): Discovery, Characterization, and Application for Reversible Control of Intracellular Protein Transport. J Am Chem Soc 2015; 137:10464-7. [DOI: 10.1021/jacs.5b05672] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
| | | | | | - Shigeru Sugiyama
- Graduate
School of Science, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
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272
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Lorent JH, Levental I. Structural determinants of protein partitioning into ordered membrane domains and lipid rafts. Chem Phys Lipids 2015; 192:23-32. [PMID: 26241883 DOI: 10.1016/j.chemphyslip.2015.07.022] [Citation(s) in RCA: 110] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Revised: 07/27/2015] [Accepted: 07/29/2015] [Indexed: 11/16/2022]
Abstract
Increasing evidence supports the existence of lateral nanoscopic lipid domains in plasma membranes, known as lipid rafts. These domains preferentially recruit membrane proteins and lipids to facilitate their interactions and thereby regulate transmembrane signaling and cellular homeostasis. The functionality of raft domains is intrinsically dependent on their selectivity for specific membrane components; however, while the physicochemical determinants of raft association for lipids are known, very few systematic studies have focused on the structural aspects that guide raft partitioning of proteins. In this review, we describe biophysical and thermodynamic aspects of raft-mimetic liquid ordered phases, focusing on those most relevant for protein partitioning. Further, we detail the variety of experimental models used to study protein-raft interactions. Finally, we review the existing literature on mechanisms for raft targeting, including lipid post-translational modifications, lipid binding, and transmembrane domain features. We conclude that while protein palmitoylation is a clear raft-targeting signal, few other general structural determinants for raft partitioning have been revealed, suggesting that many discoveries lie ahead in this burgeoning field.
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Affiliation(s)
- Joseph Helmuth Lorent
- Department for Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, USA
| | - Ilya Levental
- Department for Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, USA.
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273
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O’Mahony F, Wroblewski K, O’Byrne SM, Jiang H, Clerkin K, Benhammou J, Blaner WS, Beaven SW. Liver X receptors balance lipid stores in hepatic stellate cells through Rab18, a retinoid responsive lipid droplet protein. Hepatology 2015; 62:615-26. [PMID: 25482505 PMCID: PMC4458237 DOI: 10.1002/hep.27645] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Accepted: 12/02/2014] [Indexed: 12/11/2022]
Abstract
UNLABELLED Liver X receptors (LXRs) are determinants of hepatic stellate cell (HSC) activation and liver fibrosis. Freshly isolated HSCs from Lxrαβ(-/-) mice have increased lipid droplet (LD) size, but the functional consequences of this are unknown. Our aim was to determine whether LXRs link cholesterol to retinoid storage in HSCs and how this impacts activation. Primary HSCs from Lxrαβ(-/-) and wild-type mice were profiled by gene array during in vitro activation. Lipid content was quantified by high-performance liquid chromatography and mass spectroscopy. Primary HSCs were treated with nuclear receptor ligands, transfected with small interfering RNA and plasmid constructs, and analyzed by immunocytochemistry. Lxrαβ(-/-) HSCs have increased cholesterol and retinyl esters. The retinoid increase drives intrinsic retinoic acid receptor signaling, and activation occurs more rapidly in Lxrαβ(-/-) HSCs. We identify Rab18 as a novel retinoic acid-responsive, LD-associated protein that helps mediate stellate cell activation. Rab18 mRNA, protein, and membrane insertion increase during activation. Both Rab18 guanosine triphosphatase activity and isoprenylation are required for stellate cell LD loss and induction of activation markers. These phenomena are accelerated in Lxrαβ(-/-) HSCs, where there is greater retinoic acid flux. Conversely, Rab18 knockdown retards LD loss in culture and blocks activation, just like the functional mutants. Rab18 is also induced with acute liver injury in vivo. CONCLUSION Retinoid and cholesterol metabolism are linked in stellate cells by the LD-associated protein Rab18. Retinoid overload helps explain the profibrotic phenotype of Lxrαβ(-/-) mice, and we establish a pivotal role for Rab18 GTPase activity and membrane insertion in wild-type stellate cell activation. Interference with Rab18 may have significant therapeutic benefit in ameliorating liver fibrosis.
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Affiliation(s)
- Fiona O’Mahony
- Division of Digestive Diseases, Department of Medicine, David Geffen School of Medicine at the University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Kevin Wroblewski
- Division of Digestive Diseases, Department of Medicine, David Geffen School of Medicine at the University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Sheila M. O’Byrne
- Department of Medicine, Columbia University, New York, NY 10032, USA
| | - Hongfeng Jiang
- Department of Medicine, Columbia University, New York, NY 10032, USA
| | - Kara Clerkin
- Division of Digestive Diseases, Department of Medicine, David Geffen School of Medicine at the University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Jihane Benhammou
- Division of Digestive Diseases, Department of Medicine, David Geffen School of Medicine at the University of California Los Angeles, Los Angeles, CA 90095, USA
| | - William S. Blaner
- Department of Medicine, Columbia University, New York, NY 10032, USA
| | - Simon W. Beaven
- Division of Digestive Diseases, Department of Medicine, David Geffen School of Medicine at the University of California Los Angeles, Los Angeles, CA 90095, USA
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274
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Lathe R, Kotelevtsev Y, Mason JI. Steroid promiscuity: Diversity of enzyme action. Preface. J Steroid Biochem Mol Biol 2015; 151:1-2. [PMID: 25596328 DOI: 10.1016/j.jsbmb.2015.01.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Accepted: 01/13/2015] [Indexed: 11/25/2022]
Abstract
This Special Issue on the topic of Steroid and Sterol Signaling: Promiscuity and Diversity, dwells on the growing realization that the 'one ligand, one binding site' and 'one enzyme, one reaction' concepts are out of date. Focusing on cytochromes P450 (CYP), hydroxysteroid dehydrogenases (HSDs), and related enzymes, the Special Issue highlights that a single enzyme can bind to diverse substrates, and in different conformations, and can catalyze multiple different conversions (and in different directions), thereby, generating an unexpectedly wide spectrum of ligands that can have subtly different biological actions. This article is part of a Special Issue entitled 'Steroid/Sterol Signaling' .
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Affiliation(s)
- Richard Lathe
- Pieta Research, Edinburgh, UK; Pushchino State University and Institute of Bioorganic Chemistry, Moscow Region, Russian Federation.
| | - Yuri Kotelevtsev
- Skolkovo Institute of Science and Technology, Moscow Region, Russian Federation
| | - J Ian Mason
- MRC Centre for Reproductive Health, University of Edinburgh, Edinburgh, UK.
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275
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Abstract
Protein S-sulfenylation is the reversible oxidative modification of cysteine thiol groups to form cysteine S-sulfenic acids. Mapping the specific sites of protein S-sulfenylation onto complex proteomes is crucial to understanding the molecular mechanisms controlling redox signaling and regulation. This protocol describes global, in situ, site-specific analysis of protein S-sulfenylation using sulfenic acid-specific chemical probes and mass spectrometry (MS)-based proteomics. The major steps in this protocol are as follows: (i) optimization of conditions for selective labeling of cysteine S-sulfenic acids in intact cells with the commercially available dimedone-based probe, DYn-2; (ii) tagging the modified cysteines with a functionalized biotin reagent containing a cleavable linker via Cu(I)-catalyzed azide-alkyne cycloaddition reaction; (iii) enrichment of the biotin-tagged tryptic peptides with streptavidin; (iv) liquid chromatography-tandem MS (LC-MS/MS)-based shotgun proteomics; and (v) computational data analysis. We also outline strategies for quantitative analysis of this modification in cells responding to redox perturbations and discuss special issues pertaining to experimental design of thiol redox studies. Our chemoproteomic platform should be broadly applicable to the investigation of other bio-orthogonal chemically engineered post-translational modifications. The entire analysis protocol takes ∼1 week to complete.
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276
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277
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Grouleff J, Irudayam SJ, Skeby KK, Schiøtt B. The influence of cholesterol on membrane protein structure, function, and dynamics studied by molecular dynamics simulations. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2015; 1848:1783-95. [PMID: 25839353 DOI: 10.1016/j.bbamem.2015.03.029] [Citation(s) in RCA: 123] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Revised: 03/24/2015] [Accepted: 03/25/2015] [Indexed: 12/12/2022]
Abstract
The plasma membrane, which encapsulates human cells, is composed of a complex mixture of lipids and embedded proteins. Emerging knowledge points towards the lipids as having a regulating role in protein function. Furthermore, insight from protein crystallography has revealed several different types of lipids intimately bound to membrane proteins and peptides, hereby possibly pointing to a site of action for the observed regulation. Cholesterol is among the lipid membrane constituents most often observed to be co-crystallized with membrane proteins, and the cholesterol levels in cell membranes have been found to play an essential role in health and disease. Remarkably little is known about the mechanism of lipid regulation of membrane protein function in health as well as in disease. Herein, we review molecular dynamics simulation studies aimed at investigating the effect of cholesterol on membrane protein and peptide properties. This article is part of a Special Issue entitled: Lipid-protein interactions.
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Affiliation(s)
- Julie Grouleff
- Department of Chemistry and Interdisciplinary Nanoscience Center, Aarhus University, Langelandsgade 140, 8000 Aarhus C, Denmark
| | - Sheeba Jem Irudayam
- Department of Chemistry and Interdisciplinary Nanoscience Center, Aarhus University, Langelandsgade 140, 8000 Aarhus C, Denmark
| | - Katrine K Skeby
- Department of Chemistry and Interdisciplinary Nanoscience Center, Aarhus University, Langelandsgade 140, 8000 Aarhus C, Denmark
| | - Birgit Schiøtt
- Department of Chemistry and Interdisciplinary Nanoscience Center, Aarhus University, Langelandsgade 140, 8000 Aarhus C, Denmark.
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278
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Liu N, Van Voorst JR, Johnston JB, Kuhn LA. CholMine: Determinants and Prediction of Cholesterol and Cholate Binding Across Nonhomologous Protein Structures. J Chem Inf Model 2015; 55:747-59. [PMID: 25760928 DOI: 10.1021/ci5006542] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Identifying physiological ligands is necessary for annotating new protein structures, yet this presents a significant challenge to biologists and pharmaceutical chemists. Here we develop a predictor of cholesterol and cholate binding that works across diverse protein families, extending beyond sequence motif-based prediction. This approach combines SimSite3D site comparison with the detection of conserved interactions in cholesterol/cholate bound crystal structures to define three-dimensional interaction motifs. The resulting predictor identifies cholesterol sites with an ∼82% unbiased true positive rate in both membrane and soluble proteins, with a very low false positive rate relative to other predictors. The CholMine Web server can analyze users' structures, detect those likely to bind cholesterol/cholate, and predict the binding mode and key interactions. By deciphering the determinants of binding for these important steroids, CholMine may also aid in the design of selective inhibitors and detergents for targets such as G protein coupled receptors and bile acid receptors.
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Affiliation(s)
- Nan Liu
- †Department of Chemistry, ‡Department of Computer Science and Engineering, and §Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824-1319, United States
| | - Jeffrey R Van Voorst
- †Department of Chemistry, ‡Department of Computer Science and Engineering, and §Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824-1319, United States
| | - John B Johnston
- †Department of Chemistry, ‡Department of Computer Science and Engineering, and §Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824-1319, United States
| | - Leslie A Kuhn
- †Department of Chemistry, ‡Department of Computer Science and Engineering, and §Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824-1319, United States
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279
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Sparse feature selection methods identify unexpected global cellular response to strontium-containing materials. Proc Natl Acad Sci U S A 2015; 112:4280-5. [PMID: 25831522 DOI: 10.1073/pnas.1419799112] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Despite the increasing sophistication of biomaterials design and functional characterization studies, little is known regarding cells' global response to biomaterials. Here, we combined nontargeted holistic biological and physical science techniques to evaluate how simple strontium ion incorporation within the well-described biomaterial 45S5 bioactive glass (BG) influences the global response of human mesenchymal stem cells. Our objective analyses of whole gene-expression profiles, confirmed by standard molecular biology techniques, revealed that strontium-substituted BG up-regulated the isoprenoid pathway, suggesting an influence on both sterol metabolite synthesis and protein prenylation processes. This up-regulation was accompanied by increases in cellular and membrane cholesterol and lipid raft contents as determined by Raman spectroscopy mapping and total internal reflection fluorescence microscopy analyses and by an increase in cellular content of phosphorylated myosin II light chain. Our unexpected findings of this strong metabolic pathway regulation as a response to biomaterial composition highlight the benefits of discovery-driven nonreductionist approaches to gain a deeper understanding of global cell-material interactions and suggest alternative research routes for evaluating biomaterials to improve their design.
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280
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Lomenick B, Shi H, Huang J, Chen C. Identification and characterization of β-sitosterol target proteins. Bioorg Med Chem Lett 2015; 25:4976-4979. [PMID: 25804720 DOI: 10.1016/j.bmcl.2015.03.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Revised: 02/28/2015] [Accepted: 03/03/2015] [Indexed: 11/27/2022]
Abstract
β-Sitosterol is the most abundant plant sterol in the human diet. It is also the major component of several traditional medicines, including saw palmetto and devil's claw. Although β-sitosterol is effective against enlarged prostate in human clinical trials and has anti-cancer and anti-inflammatory activities, the mechanisms of action are poorly understood. Here, we report the identification of two new binding proteins for β-sitosterol that may underlie its beneficial effects.
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Affiliation(s)
- Brett Lomenick
- Department of Molecular and Medical Pharmacology, 23-231 Center for Health Sciences, 650 Charles E Young Dr. South, University of California Los Angeles, Los Angeles, CA 90095, USA.
| | - Heping Shi
- Department of Biochemistry, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA
| | - Jing Huang
- Department of Molecular and Medical Pharmacology, 23-231 Center for Health Sciences, 650 Charles E Young Dr. South, University of California Los Angeles, Los Angeles, CA 90095, USA; Molecular Biology Institute, University of California Los Angeles, Los Angeles, CA 90095, USA; Jonsson Comprehensive Cancer Center, University of California Los Angeles, Los Angeles, CA 90095, USA.
| | - Chuo Chen
- Department of Biochemistry, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA.
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281
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Enrich C, Rentero C, Hierro A, Grewal T. Role of cholesterol in SNARE-mediated trafficking on intracellular membranes. J Cell Sci 2015; 128:1071-81. [PMID: 25653390 DOI: 10.1242/jcs.164459] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The cell surface delivery of extracellular matrix (ECM) and integrins is fundamental for cell migration in wound healing and during cancer cell metastasis. This process is not only driven by several soluble NSF attachment protein (SNAP) receptor (SNARE) proteins, which are key players in vesicle transport at the cell surface and intracellular compartments, but is also tightly modulated by cholesterol. Cholesterol-sensitive SNAREs at the cell surface are relatively well characterized, but it is less well understood how altered cholesterol levels in intracellular compartments impact on SNARE localization and function. Recent insights from structural biology, protein chemistry and cell microscopy have suggested that a subset of the SNAREs engaged in exocytic and retrograde pathways dynamically 'sense' cholesterol levels in the Golgi and endosomal membranes. Hence, the transport routes that modulate cellular cholesterol distribution appear to trigger not only a change in the location and functioning of SNAREs at the cell surface but also in endomembranes. In this Commentary, we will discuss how disrupted cholesterol transport through the Golgi and endosomal compartments ultimately controls SNARE-mediated delivery of ECM and integrins to the cell surface and, consequently, cell migration.
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Affiliation(s)
- Carlos Enrich
- Departament de Biologia Cellular, Immunologia i Neurociències, Centre de Recerca Biomèdica CELLEX, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS). Facultat de Medicina, Universitat de Barcelona, 08036-Barcelona, Spain
| | - Carles Rentero
- Departament de Biologia Cellular, Immunologia i Neurociències, Centre de Recerca Biomèdica CELLEX, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS). Facultat de Medicina, Universitat de Barcelona, 08036-Barcelona, Spain
| | - Aitor Hierro
- Structural Biology Unit, CIC bioGUNE, Bizkaia Technology Park, 48160 Derio; IKERBASQUE, Basque Foundation for Science, 48013 Bilbao, Spain
| | - Thomas Grewal
- Faculty of Pharmacy, University of Sydney, Sydney, NSW 2006, Australia
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282
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Abstract
Eukaryotic and prokaryotic organisms possess huge numbers of uncharacterized enzymes. Selective inhibitors offer powerful probes for assigning functions to enzymes in native biological systems. Here, we discuss how the chemical proteomic platform activity-based protein profiling (ABPP) can be implemented to discover selective and in vivo-active inhibitors for enzymes. We further describe how these inhibitors have been used to delineate the biochemical and cellular functions of enzymes, leading to the discovery of metabolic and signaling pathways that make important contributions to human physiology and disease. These studies demonstrate the value of selective chemical probes as drivers of biological inquiry.
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Affiliation(s)
- Micah J Niphakis
- The Skaggs Institute for Chemical Biology and the Department of Chemical Physiology, The Scripps Research Institute, La Jolla, California 92037;
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283
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Lee HJ, Zhang W, Zhang D, Yang Y, Liu B, Barker EL, Buhman KK, Slipchenko LV, Dai M, Cheng JX. Assessing cholesterol storage in live cells and C. elegans by stimulated Raman scattering imaging of phenyl-Diyne cholesterol. Sci Rep 2015; 5:7930. [PMID: 25608867 PMCID: PMC4302291 DOI: 10.1038/srep07930] [Citation(s) in RCA: 99] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Accepted: 12/22/2014] [Indexed: 02/07/2023] Open
Abstract
We report a cholesterol imaging method using rationally synthesized phenyl-diyne cholesterol (PhDY-Chol) and stimulated Raman scattering (SRS) microscope. The phenyl-diyne group is biologically inert and provides a Raman scattering cross section that is 88 times larger than the endogenous C = O stretching mode. SRS microscopy offers an imaging speed that is faster than spontaneous Raman microscopy by three orders of magnitude, and a detection sensitivity of 31 μM PhDY-Chol (~1,800 molecules in the excitation volume). Inside living CHO cells, PhDY-Chol mimics the behavior of cholesterol, including membrane incorporation and esterification. In a cellular model of Niemann-Pick type C disease, PhDY-Chol reflects the lysosomal accumulation of cholesterol, and shows relocation to lipid droplets after HPβCD treatment. In live C. elegans, PhDY-Chol mimics cholesterol uptake by intestinal cells and reflects cholesterol storage. Together, our work demonstrates an enabling platform for study of cholesterol storage and trafficking in living cells and vital organisms.
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Affiliation(s)
- Hyeon Jeong Lee
- Interdisciplinary Life Science Program, Purdue University, West Lafayette, IN, USA
- Department of Comparative Pathobiology, Purdue University, West Lafayette, IN, USA
| | - Wandi Zhang
- Department of Chemistry, Purdue University, West Lafayette, IN, USA
| | - Delong Zhang
- Department of Chemistry, Purdue University, West Lafayette, IN, USA
| | - Yang Yang
- Department of Chemistry, Purdue University, West Lafayette, IN, USA
| | - Bin Liu
- National Key Laboratory of Science and Technology on Tunable Laser, Harbin Institute of Technology, Harbin 150080, China
| | - Eric L. Barker
- Interdisciplinary Life Science Program, Purdue University, West Lafayette, IN, USA
- Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN, USA
| | - Kimberly K. Buhman
- Interdisciplinary Life Science Program, Purdue University, West Lafayette, IN, USA
- Department of Nutrition Science, Purdue University, West Lafayette, IN, USA
| | | | - Mingji Dai
- Interdisciplinary Life Science Program, Purdue University, West Lafayette, IN, USA
- Department of Chemistry, Purdue University, West Lafayette, IN, USA
| | - Ji-Xin Cheng
- Interdisciplinary Life Science Program, Purdue University, West Lafayette, IN, USA
- Department of Chemistry, Purdue University, West Lafayette, IN, USA
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, USA
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284
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Peng T, Hang HC. Bifunctional fatty acid chemical reporter for analyzing S-palmitoylated membrane protein-protein interactions in mammalian cells. J Am Chem Soc 2015; 137:556-9. [PMID: 25575299 PMCID: PMC4303541 DOI: 10.1021/ja502109n] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Studying the functions of S-palmitoylated proteins in cells can be challenging due to the membrane targeting property and dynamic nature of protein S-palmitoylation. New strategies are therefore needed to specifically capture S-palmitoylated protein complexes in cellular membranes for dissecting their functions in vivo. Here we present a bifunctional fatty acid chemical reporter, x-alk-16, which contains an alkyne and a diazirine, for metabolic labeling of S-palmitoylated proteins and photo-cross-linking of their involved protein complexes in mammalian cells. We demonstrate that x-alk-16 can be metabolically incorporated into known S-palmitoylated proteins such as H-Ras and IFITM3, a potent antiviral protein, and induce covalent cross-linking of IFITM3 oligomerization as well as its specific interactions with other membrane proteins upon in-cell photoactivation. Moreover, integration of x-alk-16-induced photo-cross-linking with label-free quantitative proteomics allows identification of new IFITM3 interacting proteins.
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Affiliation(s)
- Tao Peng
- Laboratory of Chemical Biology and Bacterial Pathogenesis, The Rockefeller University, New York, New York 10065, United States
| | - Howard C. Hang
- Laboratory of Chemical Biology and Bacterial Pathogenesis, The Rockefeller University, New York, New York 10065, United States
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285
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Alvarez-Guaita A, Vilà de Muga S, Owen DM, Williamson D, Magenau A, García-Melero A, Reverter M, Hoque M, Cairns R, Cornely R, Tebar F, Grewal T, Gaus K, Ayala-Sanmartín J, Enrich C, Rentero C. Evidence for annexin A6-dependent plasma membrane remodelling of lipid domains. Br J Pharmacol 2015; 172:1677-90. [PMID: 25409976 DOI: 10.1111/bph.13022] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Revised: 11/11/2014] [Accepted: 11/14/2014] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND AND PURPOSE Annexin A6 (AnxA6) is a calcium-dependent phospholipid-binding protein that can be recruited to the plasma membrane to function as a scaffolding protein to regulate signal complex formation, endo- and exocytic pathways as well as distribution of cellular cholesterol. Here, we have investigated how AnxA6 influences the membrane order. EXPERIMENTAL APPROACH We used Laurdan and di-4-ANEPPDHQ staining in (i) artificial membranes; (ii) live cells to investigate membrane packing and ordered lipid phases; and (iii) a super-resolution imaging (photoactivated localization microscopy, PALM) and Ripley's K second-order point pattern analysis approach to assess how AnxA6 regulates plasma membrane order domains and protein clustering. KEY RESULTS In artificial membranes, purified AnxA6 induced a global increase in membrane order. However, confocal microscopy using di-4-ANEPPDHQ in live cells showed that cells expressing AnxA6, which reduces plasma membrane cholesterol levels and modifies the actin cytoskeleton meshwork, displayed a decrease in membrane order (∼15 and 30% in A431 and MEF cells respectively). PALM data from Lck10 and Src15 membrane raft/non-raft markers revealed that AnxA6 expression induced clustering of both raft and non-raft markers. Altered clustering of Lck10 and Src15 in cells expressing AnxA6 was also observed after cholesterol extraction with methyl-β-cyclodextrin or actin cytoskeleton disruption with latrunculin B. CONCLUSIONS AND IMPLICATIONS AnxA6-induced plasma membrane remodelling indicated that elevated AnxA6 expression decreased membrane order through the regulation of cellular cholesterol homeostasis and the actin cytoskeleton. This study provides the first evidence from live cells that support current models of annexins as membrane organizers.
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Affiliation(s)
- Anna Alvarez-Guaita
- Departament de Biologia Cel·lular, Immunologia i Neurociències, Facultat de Medicina, Universitat de Barcelona, Barcelona, Spain
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286
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Owen TS, Xie XJ, Laraway B, Ngoje G, Wang C, Callahan BP. Active site targeting of hedgehog precursor protein with phenylarsine oxide. Chembiochem 2014; 16:55-8. [PMID: 25418613 DOI: 10.1002/cbic.201402421] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Indexed: 01/19/2023]
Abstract
Hedgehog proteins, signaling molecules implicated in human embryo development and cancer, can be inhibited at the stage of autoprocessing by the trivalent arsenical phenyl arsine oxide (PhAs(III) ). The interaction (apparent Ki , 4 × 10(-7) M) is characterized by an optical binding assay and by NMR spectroscopy. PhAs(III) appears to be the first validated inhibitor of hedgehog autoprocessing, which is unique to hedgehog proteins and essential for biological activity.
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Affiliation(s)
- Timothy S Owen
- Chemistry Department, Binghamton University, 4400 Vestal Parkway East, Binghamton, New York (USA)
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287
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Valenza M, Marullo M, Di Paolo E, Cesana E, Zuccato C, Biella G, Cattaneo E. Disruption of astrocyte-neuron cholesterol cross talk affects neuronal function in Huntington's disease. Cell Death Differ 2014; 22:690-702. [PMID: 25301063 DOI: 10.1038/cdd.2014.162] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Revised: 08/13/2014] [Accepted: 09/03/2014] [Indexed: 01/22/2023] Open
Abstract
In the adult brain, neurons require local cholesterol production, which is supplied by astrocytes through apoE-containing lipoproteins. In Huntington's disease (HD), such cholesterol biosynthesis in the brain is severely reduced. Here we show that this defect, occurring in astrocytes, is detrimental for HD neurons. Astrocytes bearing the huntingtin protein containing increasing CAG repeats secreted less apoE-lipoprotein-bound cholesterol in the medium. Conditioned media from HD astrocytes and lipoprotein-depleted conditioned media from wild-type (wt) astrocytes were equally detrimental in a neurite outgrowth assay and did not support synaptic activity in HD neurons, compared with conditions of cholesterol supplementation or conditioned media from wt astrocytes. Molecular perturbation of cholesterol biosynthesis and efflux in astrocytes caused similarly altered astrocyte-neuron cross talk, whereas enhancement of glial SREBP2 and ABCA1 function reversed the aspects of neuronal dysfunction in HD. These findings indicate that astrocyte-mediated cholesterol homeostasis could be a potential therapeutic target to ameliorate neuronal dysfunction in HD.
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Affiliation(s)
- M Valenza
- Department of Biosciences and Centre for Stem Cell Research, Università degli Studi di Milano, Milano, Italy
| | - M Marullo
- Department of Biosciences and Centre for Stem Cell Research, Università degli Studi di Milano, Milano, Italy
| | - E Di Paolo
- Department of Biosciences and Centre for Stem Cell Research, Università degli Studi di Milano, Milano, Italy
| | - E Cesana
- Department of Biology and Biotechnology, Università degli Studi di Pavia, Pavia, Italy
| | - C Zuccato
- Department of Biosciences and Centre for Stem Cell Research, Università degli Studi di Milano, Milano, Italy
| | - G Biella
- Department of Biology and Biotechnology, Università degli Studi di Pavia, Pavia, Italy
| | - E Cattaneo
- Department of Biosciences and Centre for Stem Cell Research, Università degli Studi di Milano, Milano, Italy
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288
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Squalene mono-oxygenase, a key enzyme in cholesterol synthesis, is stabilized by unsaturated fatty acids. Biochem J 2014; 461:435-42. [PMID: 24840124 DOI: 10.1042/bj20131404] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
SM (squalene mono-oxygenase) catalyses the first oxygenation step in cholesterol synthesis, immediately before the formation of the steroid backbone at lanosterol. SM is an important control point in the pathway, and is regulated at the post-translational level by accelerated cholesterol-dependent ubiquitination and proteasomal degradation, which is associated with the accumulation of squalene. Using model cell systems, we report that SM is stabilized by unsaturated fatty acids. Treatment with unsaturated fatty acids such as oleate, but not saturated fatty acids, increased protein levels of SM or SM-N100-GFP (the first 100 amino acids of SM fused to GFP) at the post-translational level and partially overcame cholesterol-dependent degradation, as well as reversing cholesterol-dependent squalene accumulation. Maximum stabilization required activation of fatty acids, but not triacylglycerol or phosphatidylcholine synthesis. The mechanism of oleate-mediated stabilization appeared to occur through reduced ubiquitination by the E3 ubiquitin ligase MARCH6. Stabilization of a cholesterol biosynthetic enzyme by unsaturated fatty acids may help maintain a constant cholesterol/phospholipid ratio.
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289
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Sharpe LJ, Cook ECL, Zelcer N, Brown AJ. The UPS and downs of cholesterol homeostasis. Trends Biochem Sci 2014; 39:527-35. [PMID: 25220377 DOI: 10.1016/j.tibs.2014.08.008] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Revised: 08/18/2014] [Accepted: 08/21/2014] [Indexed: 11/26/2022]
Abstract
An emerging theme in the regulation of cholesterol homeostasis is the role of the ubiquitin proteasome system (UPS), through which proteins are ubiquitylated and then degraded in response to specific signals. The UPS controls all aspects of cholesterol metabolism including its synthesis, uptake, and efflux. We review here recent work uncovering the ubiquitylation and degradation of key players in cholesterol homeostasis. This includes the low-density lipoprotein (LDL) receptor, transcription factors (sterol regulatory element binding proteins and liver X receptors), flux-controlling enzymes in cholesterol synthesis (3-hydroxy-3-methylglutaryl-CoA reductase and squalene monooxygenase), and cholesterol exporters (ATP-binding cassette transporters ABCA1 and ABCG1). We explore which E3 ligases are involved, and identify areas deserving of further research.
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Affiliation(s)
- Laura J Sharpe
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, NSW 2052, Australia
| | - Emma C L Cook
- Department of Medical Biochemistry, Academic Medical Center, University of Amsterdam, Meibergdreef 15, 1105AZ Amsterdam, The Netherlands
| | - Noam Zelcer
- Department of Medical Biochemistry, Academic Medical Center, University of Amsterdam, Meibergdreef 15, 1105AZ Amsterdam, The Netherlands.
| | - Andrew J Brown
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, NSW 2052, Australia.
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290
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Lanning BR, Whitby LR, Dix MM, Douhan J, Gilbert AM, Hett EC, Johnson TO, Joslyn C, Kath JC, Niessen S, Roberts LR, Schnute ME, Wang C, Hulce JJ, Wei B, Whiteley LO, Hayward MM, Cravatt BF. A road map to evaluate the proteome-wide selectivity of covalent kinase inhibitors. Nat Chem Biol 2014; 10:760-767. [PMID: 25038787 PMCID: PMC4138289 DOI: 10.1038/nchembio.1582] [Citation(s) in RCA: 254] [Impact Index Per Article: 25.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Accepted: 06/03/2014] [Indexed: 01/05/2023]
Abstract
Kinases are principal components of signal transduction pathways and the focus of intense basic and drug discovery research. Irreversible inhibitors that covalently modify non-catalytic cysteines in kinase active sites have emerged as valuable probes and approved drugs. Many protein classes, however, have functional cysteines, and therefore understanding the proteome-wide selectivity of covalent kinase inhibitors is imperative. Here, we accomplish this objective using activity-based protein profiling coupled with quantitative MS to globally map the targets, both specific and nonspecific, of covalent kinase inhibitors in human cells. Many of the specific off-targets represent nonkinase proteins that, notably, have conserved active site cysteines. We define windows of selectivity for covalent kinase inhibitors and show that, when these windows are exceeded, rampant proteome-wide reactivity and kinase target-independent cell death conjointly occur. Our findings, taken together, provide an experimental road map to illuminate opportunities and surmount challenges for the development of covalent kinase inhibitors.
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Affiliation(s)
- Bryan R. Lanning
- The Skaggs Institute for Chemical Biology and Department of Chemical Physiology, The Scripps Research Institute, 10550 N. Torrey Pines Rd. La Jolla, CA, 92307
| | - Landon R. Whitby
- The Skaggs Institute for Chemical Biology and Department of Chemical Physiology, The Scripps Research Institute, 10550 N. Torrey Pines Rd. La Jolla, CA, 92307
| | - Melissa M. Dix
- The Skaggs Institute for Chemical Biology and Department of Chemical Physiology, The Scripps Research Institute, 10550 N. Torrey Pines Rd. La Jolla, CA, 92307
| | - John Douhan
- Pfizer Worldwide Research and Development, 200 Cambridge Park Drive, Cambridge, MA 02140
| | - Adam M. Gilbert
- Pfizer Worldwide Research and Development, Eastern Point Road, Groton, CT 06340
| | - Erik C. Hett
- Pfizer Worldwide Research and Development, 200 Cambridge Park Drive, Cambridge, MA 02140
| | - Theodore O. Johnson
- Pfizer Worldwide Research and Development, 10770 Science Park Drive, San Diego, CA 92121
| | - Chris Joslyn
- The Skaggs Institute for Chemical Biology and Department of Chemical Physiology, The Scripps Research Institute, 10550 N. Torrey Pines Rd. La Jolla, CA, 92307
| | - John C. Kath
- Pfizer Worldwide Research and Development, 10770 Science Park Drive, San Diego, CA 92121
| | - Sherry Niessen
- Pfizer Worldwide Research and Development, 10770 Science Park Drive, San Diego, CA 92121
| | - Lee R. Roberts
- Pfizer Worldwide Research and Development, 200 Cambridge Park Drive, Cambridge, MA 02140
| | - Mark E. Schnute
- Pfizer Worldwide Research and Development, 200 Cambridge Park Drive, Cambridge, MA 02140
| | - Chu Wang
- The Skaggs Institute for Chemical Biology and Department of Chemical Physiology, The Scripps Research Institute, 10550 N. Torrey Pines Rd. La Jolla, CA, 92307
| | - Jonathan J. Hulce
- The Skaggs Institute for Chemical Biology and Department of Chemical Physiology, The Scripps Research Institute, 10550 N. Torrey Pines Rd. La Jolla, CA, 92307
| | - Baoxian Wei
- Pfizer Worldwide Research and Development, 1 Burtt Rd, Andover, MA 01810
| | | | - Matthew M. Hayward
- Pfizer Worldwide Research and Development, Eastern Point Road, Groton, CT 06340
| | - Benjamin F. Cravatt
- The Skaggs Institute for Chemical Biology and Department of Chemical Physiology, The Scripps Research Institute, 10550 N. Torrey Pines Rd. La Jolla, CA, 92307
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291
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Yang J, Gupta V, Carroll KS, Liebler DC. Site-specific mapping and quantification of protein S-sulphenylation in cells. Nat Commun 2014; 5:4776. [PMID: 25175731 PMCID: PMC4167403 DOI: 10.1038/ncomms5776] [Citation(s) in RCA: 190] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Accepted: 07/22/2014] [Indexed: 02/06/2023] Open
Abstract
Cysteine S-sulphenylation provides redox regulation of protein functions, but the global cellular impact of this transient post-translational modification remains unexplored. We describe a chemoproteomic workflow to map and quantify over 1,000 S-sulphenylation sites on more than 700 proteins in intact cells. Quantitative analysis of human cells stimulated with hydrogen peroxide or epidermal growth factor measured hundreds of site selective redox changes. Different cysteines in the same proteins displayed dramatic differences in susceptibility to S-sulphenylation. Newly discovered S-sulphenylations provided mechanistic support for proposed cysteine redox reactions and suggested novel redox mechanisms, including S-sulphenyl-mediated redox regulation of the transcription factor HIF1A by SIRT6. S-sulphenylation is favored at solvent-exposed protein surfaces and is associated with sequence motifs that are distinct from those for other thiol modifications. S-sulphenylations affect regulators of phosphorylation, acetylation and ubiquitylation, which suggest regulatory crosstalk between redox control and signalling pathways.
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Affiliation(s)
- Jing Yang
- 1] Departmemt of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-6350, USA [2] Jim Ayers Institute for Precancer Detection and Diagnosis, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-6350, USA
| | - Vinayak Gupta
- Department of Chemistry, The Scripps Research Institute, Jupiter, Florida 33458, USA
| | - Kate S Carroll
- Department of Chemistry, The Scripps Research Institute, Jupiter, Florida 33458, USA
| | - Daniel C Liebler
- 1] Departmemt of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-6350, USA [2] Jim Ayers Institute for Precancer Detection and Diagnosis, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-6350, USA
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292
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Schiapparelli LM, McClatchy DB, Liu HH, Sharma P, Yates JR, Cline HT. Direct detection of biotinylated proteins by mass spectrometry. J Proteome Res 2014; 13:3966-78. [PMID: 25117199 PMCID: PMC4156236 DOI: 10.1021/pr5002862] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Mass spectrometric strategies to identify protein subpopulations involved in specific biological functions rely on covalently tagging biotin to proteins using various chemical modification methods. The biotin tag is primarily used for enrichment of the targeted subpopulation for subsequent mass spectrometry (MS) analysis. A limitation of these strategies is that MS analysis does not easily discriminate unlabeled contaminants from the labeled protein subpopulation under study. To solve this problem, we developed a flexible method that only relies on direct MS detection of biotin-tagged proteins called "Direct Detection of Biotin-containing Tags" (DiDBiT). Compared with conventional targeted proteomic strategies, DiDBiT improves direct detection of biotinylated proteins ∼200 fold. We show that DiDBiT is applicable to several protein labeling protocols in cell culture and in vivo using cell permeable NHS-biotin and incorporation of the noncanonical amino acid, azidohomoalanine (AHA), into newly synthesized proteins, followed by click chemistry tagging with biotin. We demonstrate that DiDBiT improves the direct detection of biotin-tagged newly synthesized peptides more than 20-fold compared to conventional methods. With the increased sensitivity afforded by DiDBiT, we demonstrate the MS detection of newly synthesized proteins labeled in vivo in the rodent nervous system with unprecedented temporal resolution as short as 3 h.
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Affiliation(s)
- Lucio Matias Schiapparelli
- The Dorris Neuroscience Center, Department of Molecular and Cellular Neuroscience, ‡Department of Chemical Physiology, and §Kellogg School of Science and Technology, The Scripps Research Institute , La Jolla, California 92037, United States
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293
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Lipids in the nervous system: from biochemistry and molecular biology to patho-physiology. Biochim Biophys Acta Mol Cell Biol Lipids 2014; 1851:51-60. [PMID: 25150974 DOI: 10.1016/j.bbalip.2014.08.011] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Revised: 08/08/2014] [Accepted: 08/12/2014] [Indexed: 12/16/2022]
Abstract
Lipids in the nervous system accomplish a great number of key functions, from synaptogenesis to impulse conduction, and more. Most of the lipids of the nervous system are localized in myelin sheaths. It has long been known that myelin structure and brain homeostasis rely on specific lipid-protein interactions and on specific cell-to-cell signaling. In more recent years, the growing advances in large-scale technologies and genetically modified animal models have provided valuable insights into the role of lipids in the nervous system. Key findings recently emerged in these areas are here summarized. In addition, we briefly discuss how this new knowledge can open novel approaches for the treatment of diseases associated with alteration of lipid metabolism/homeostasis in the nervous system. This article is part of a Special Issue entitled Linking transcription to physiology in lipidomics.
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294
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Ciepla P, Konitsiotis AD, Serwa RA, Masumoto N, Leong WP, Dallman MJ, Magee AI, Tate EW. New chemical probes targeting cholesterylation of Sonic Hedgehog in human cells and zebrafish. Chem Sci 2014; 5:4249-4259. [PMID: 25574372 PMCID: PMC4285107 DOI: 10.1039/c4sc01600a] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Accepted: 07/25/2014] [Indexed: 12/17/2022] Open
Abstract
Alkynyl-cholesterol probes tag and track Hedgehog protein, illuminating the role of protein cholesterylation in secretion, transport complex formation and signalling, and enabling quantitative proteomic analysis, imaging, and detection of cholesterylation in developing zebrafish.
Sonic Hedgehog protein (Shh) is a morphogen molecule important in embryonic development and in the progression of many cancer types in which it is aberrantly overexpressed. Fully mature Shh requires attachment of cholesterol and palmitic acid to its C- and N-termini, respectively. The study of lipidated Shh has been challenging due to the limited array of tools available, and the roles of these posttranslational modifications are poorly understood. Herein, we describe the development and validation of optimised alkynyl sterol probes that efficiently tag Shh cholesterylation and enable its visualisation and analysis through bioorthogonal ligation to reporters. An optimised probe was shown to be an excellent cholesterol biomimetic in the context of Shh, enabling appropriate release of tagged Shh from signalling cells, formation of multimeric transport complexes and signalling. We have used this probe to determine the size of transport complexes of lipidated Shh in culture medium and expression levels of endogenous lipidated Shh in pancreatic ductal adenocarcinoma cell lines through quantitative chemical proteomics, as well as direct visualisation of the probe by fluorescence microscopy and detection of cholesterylated Hedgehog protein in developing zebrafish embryos. These sterol probes provide a set of novel and well-validated tools that can be used to investigate the role of lipidation on activity of Shh, and potentially other members of the Hedgehog protein family.
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Affiliation(s)
- Paulina Ciepla
- Department of Chemistry , Imperial College London , Exhibition Road , London SW7 2AZ , UK . ; Institute of Chemical Biology , Imperial College London , Exhibition Road , London SW7 2AZ , UK .
| | - Antonios D Konitsiotis
- National Heart and Lung Institute , Imperial College London , Exhibition Road , London SW7 2AZ , UK
| | - Remigiusz A Serwa
- Department of Chemistry , Imperial College London , Exhibition Road , London SW7 2AZ , UK .
| | - Naoko Masumoto
- Department of Chemistry , Imperial College London , Exhibition Road , London SW7 2AZ , UK . ; Institute of Chemical Biology , Imperial College London , Exhibition Road , London SW7 2AZ , UK .
| | - Wai P Leong
- Department of Chemistry , Imperial College London , Exhibition Road , London SW7 2AZ , UK .
| | - Margaret J Dallman
- Institute of Chemical Biology , Imperial College London , Exhibition Road , London SW7 2AZ , UK . ; Department of Life Sciences , Imperial College London , Exhibition Road , London SW7 2AZ , UK
| | - Anthony I Magee
- Institute of Chemical Biology , Imperial College London , Exhibition Road , London SW7 2AZ , UK . ; National Heart and Lung Institute , Imperial College London , Exhibition Road , London SW7 2AZ , UK
| | - Edward W Tate
- Department of Chemistry , Imperial College London , Exhibition Road , London SW7 2AZ , UK . ; Institute of Chemical Biology , Imperial College London , Exhibition Road , London SW7 2AZ , UK .
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295
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Weiser BP, Salari R, Eckenhoff RG, Brannigan G. Computational investigation of cholesterol binding sites on mitochondrial VDAC. J Phys Chem B 2014; 118:9852-60. [PMID: 25080204 PMCID: PMC4141696 DOI: 10.1021/jp504516a] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
![]()
The
mitochondrial voltage-dependent anion channel (VDAC) allows
passage of ions and metabolites across the mitochondrial outer membrane.
Cholesterol binds mammalian VDAC, and we investigated the effects
of binding to human VDAC1 with atomistic molecular dynamics simulations
that totaled 1.4 μs. We docked cholesterol to specific sites
on VDAC that were previously identified with NMR, and we tested the
reliability of multiple docking results in each site with simulations.
The most favorable binding modes were used to build a VDAC model with
cholesterol occupying five unique sites, and during multiple 100 ns
simulations, cholesterol stably and reproducibly remained bound to
the protein. For comparison, VDAC was simulated in systems with identical
components but with cholesterol initially unbound. The dynamics of
loops that connect adjacent β-strands were most affected by
bound cholesterol, with the averaged root-mean-square fluctuation
(RMSF) of multiple residues altered by 20–30%. Cholesterol
binding also stabilized charged residues inside the channel and localized
the surrounding electrostatic potentials. Despite this, ion diffusion
through the channel was not significantly affected by bound cholesterol,
as evidenced by multi-ion potential of mean force measurements. Although
we observed modest effects of cholesterol on the open channel, our
model will be particularly useful in experiments that investigate
how cholesterol affects VDAC function under applied electrochemical
forces and also how other ligands and proteins interact with the channel.
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Affiliation(s)
- Brian P Weiser
- Department of Anesthesiology and Critical Care and ‡Department of Pharmacology, University of Pennsylvania Perelman School of Medicine , Philadelphia, Pennsylvania 19104, United States
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296
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Khor VK, Ahrends R, Lin Y, Shen WJ, Adams CM, Roseman AN, Cortez Y, Teruel MN, Azhar S, Kraemer FB. The proteome of cholesteryl-ester-enriched versus triacylglycerol-enriched lipid droplets. PLoS One 2014; 9:e105047. [PMID: 25111084 PMCID: PMC4128735 DOI: 10.1371/journal.pone.0105047] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Accepted: 07/19/2014] [Indexed: 12/20/2022] Open
Abstract
Within cells, lipids are stored in the form of lipid droplets (LDs), consisting of a neutral lipid core, surrounded by a phospholipid monolayer and an outer layer of protein. LDs typically accumulate either triacylglycerol (TAG) and diacylglycerol or cholesteryl ester (CE), depending on the type of tissue. Recently, there has been an increased interest in the proteins that surround LDs. LD proteins have been found to be quite diverse, from structural proteins to metabolic enzymes, proteins involved in vesicular transport, and proteins that may play a role in LD formation. Previous proteomics analyses have focused on TAG-enriched LDs, whereas CE-enriched LDs have been largely ignored. Our study has compared the LD proteins from CE-enriched LDs to TAG-enriched LDs in steroidogenic cells. In primary rat granulosa cells loaded with either HDL to produce CE-enriched LDs or fatty acids to produce TAG-enriched LDs, 61 proteins were found to be elevated in CE-enriched LDs and 40 proteins elevated in TAG-enriched LDs with 278 proteins in similar amounts. Protein expression was further validated by selected reaction monitoring (SRM) mass spectrometry (MS). SRM verified expression of 25 of 27 peptides that were previously detected by tandem mass tagging MS. Several proteins were confirmed to be elevated in CE-enriched LDs by SRM including the intermediate filament vimentin. This study is the first to compare the proteins found on CE-enriched LDs with TAG-enriched LDs and constitutes the first step in creating a better understanding of the proteins found on CE-enriched LDs in steroidogenic cells.
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Affiliation(s)
- Victor K. Khor
- Division of Endocrinology, Gerontology and Metabolism, Stanford University, Stanford, California, United States of America
- Veterans Affairs Palo Alto Health Care System, Palo Alto, California, United States of America
| | - Robert Ahrends
- Department of Chemical and Systems Biology, Stanford University, Stanford, California, United States of America
| | - Ye Lin
- Division of Endocrinology, Gerontology and Metabolism, Stanford University, Stanford, California, United States of America
- Veterans Affairs Palo Alto Health Care System, Palo Alto, California, United States of America
| | - Wen-Jun Shen
- Division of Endocrinology, Gerontology and Metabolism, Stanford University, Stanford, California, United States of America
- Veterans Affairs Palo Alto Health Care System, Palo Alto, California, United States of America
| | - Christopher M. Adams
- Mass Spectrometry Center, Stanford University, Stanford, California, United States of America
| | - Ann Nomoto Roseman
- Veterans Affairs Palo Alto Health Care System, Palo Alto, California, United States of America
| | - Yuan Cortez
- Veterans Affairs Palo Alto Health Care System, Palo Alto, California, United States of America
| | - Mary N. Teruel
- Department of Chemical and Systems Biology, Stanford University, Stanford, California, United States of America
| | - Salman Azhar
- Division of Gastroenterology and Hepatology, Department of Medicine, Stanford University, Stanford, California, United States of America
- Veterans Affairs Palo Alto Health Care System, Palo Alto, California, United States of America
| | - Fredric B. Kraemer
- Division of Endocrinology, Gerontology and Metabolism, Stanford University, Stanford, California, United States of America
- Veterans Affairs Palo Alto Health Care System, Palo Alto, California, United States of America
- * E-mail:
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297
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Peng T, Yuan X, Hang HC. Turning the spotlight on protein-lipid interactions in cells. Curr Opin Chem Biol 2014; 21:144-53. [PMID: 25129056 PMCID: PMC4206213 DOI: 10.1016/j.cbpa.2014.07.015] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Revised: 07/14/2014] [Accepted: 07/16/2014] [Indexed: 12/27/2022]
Abstract
Protein function is largely dependent on coordinated and dynamic interactions of the protein with biomolecules including other proteins, nucleic acids and lipids. Although powerful methods for global profiling of protein-protein and protein-nucleic acid interactions are available, proteome-wide mapping of protein-lipid interactions is still challenging and rarely performed. The emergence of bifunctional lipid probes with photoactivatable and clickable groups offers new chemical tools for globally profiling protein-lipid interactions under cellular contexts. In this review, we summarize recent advances in the development of bifunctional lipid probes for studying protein-lipid interactions. We also highlight how in vivo photocrosslinking reactions contribute to the characterization of lipid-binding proteins and lipidation-mediated protein-protein interactions.
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Affiliation(s)
- Tao Peng
- Laboratory of Chemical Biology and Microbial Pathogenesis, The Rockefeller University, New York, NY 10065, United States
| | - Xiaoqiu Yuan
- Laboratory of Chemical Biology and Microbial Pathogenesis, The Rockefeller University, New York, NY 10065, United States
| | - Howard C Hang
- Laboratory of Chemical Biology and Microbial Pathogenesis, The Rockefeller University, New York, NY 10065, United States.
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298
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Kambe T, Correia BE, Niphakis MJ, Cravatt BF. Mapping the protein interaction landscape for fully functionalized small-molecule probes in human cells. J Am Chem Soc 2014; 136:10777-82. [PMID: 25045785 PMCID: PMC4120992 DOI: 10.1021/ja505517t] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
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Phenotypic screening provides a means
to discover small molecules
that perturb cell biological processes. Discerning the proteins and
biochemical pathways targeted by screening hits, however, remains
technically challenging. We recently described the use of small molecules
bearing photoreactive groups and latent affinity handles as fully
functionalized probes for integrated phenotypic screening and target
identification. The general utility of such probes, or, for that matter,
any small-molecule screening library, depends on the scope of their
protein interactions in cells, a parameter that remains largely unexplored.
Here, we describe the synthesis of an ∼60-member fully functionalized
probe library, prepared from Ugi-azide condensation reactions to impart
structural diversity and introduce diazirine and alkyne functionalities
for target capture and enrichment, respectively. In-depth mass spectrometry-based
analysis revealed a diverse array of probe targets in human cells,
including enzymes, channels, adaptor and scaffolding proteins, and
proteins of uncharacterized function. For many of these proteins,
ligands have not yet been described. Most of the probe–protein
interactions showed well-defined structure–activity relationships
across the probe library and were blocked by small-molecule competitors
in cells. These findings indicate that fully functionalized small
molecules canvas diverse segments of the human proteome and hold promise
as pharmacological probes of cell biology.
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Affiliation(s)
- Tohru Kambe
- The Skaggs Institute for Chemical Biology and Department of Chemical Physiology, The Scripps Research Institute , 10550 North Torrey Pines Road, La Jolla, California 92037, United States
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299
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Sheng R, Kim H, Lee H, Xin Y, Chen Y, Tian W, Cui Y, Choi JC, Doh J, Han JK, Cho W. Cholesterol selectively activates canonical Wnt signalling over non-canonical Wnt signalling. Nat Commun 2014; 5:4393. [PMID: 25024088 PMCID: PMC4100210 DOI: 10.1038/ncomms5393] [Citation(s) in RCA: 102] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Accepted: 06/13/2014] [Indexed: 12/19/2022] Open
Abstract
Wnt proteins control diverse biological processes through β-catenin-dependent canonical signalling and β-catenin-independent non-canonical signalling. The mechanisms by which these signalling pathways are differentially triggered and controlled are not fully understood. Dishevelled (Dvl) is a scaffold protein that serves as the branch point of these pathways. Here, we show that cholesterol selectively activates canonical Wnt signalling over non-canonical signalling under physiological conditions by specifically facilitating the membrane recruitment of the PDZ domain of Dvl and its interaction with other proteins. Single-molecule imaging analysis shows that cholesterol is enriched around the Wnt-activated Frizzled and low-density lipoprotein receptor-related protein 5/6 receptors and plays an essential role for Dvl-mediated formation and maintenance of the canonical Wnt signalling complex. Collectively, our results suggest a new regulatory role of cholesterol in Wnt signalling and a potential link between cellular cholesterol levels and the balance between canonical and non-canonical Wnt signalling activities.
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Affiliation(s)
- Ren Sheng
- Department of Chemistry, University of Illinois at Chicago, Chicago, IL 60607, USA
| | | | | | - Yao Xin
- Department of Chemistry, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Yong Chen
- Department of Chemistry, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Wen Tian
- Department of Chemistry, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Yang Cui
- Department of Chemistry, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Jong-Cheol Choi
- Mechanical Engineering, Pohang University of Science and Technology, Pohang, 790-784, Korea
| | - Junsang Doh
- Mechanical Engineering, Pohang University of Science and Technology, Pohang, 790-784, Korea
| | | | - Wonhwa Cho
- Department of Chemistry, University of Illinois at Chicago, Chicago, IL 60607, USA
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300
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Hoque M, Rentero C, Cairns R, Tebar F, Enrich C, Grewal T. Annexins — Scaffolds modulating PKC localization and signaling. Cell Signal 2014; 26:1213-25. [DOI: 10.1016/j.cellsig.2014.02.012] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Accepted: 02/22/2014] [Indexed: 12/15/2022]
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